Radiology September 2010

Volume: 9 • Issue: 3 & 4 September 2010

Special Feature

A Timeto

Shape-up

• Initial Management of Polytrauma Patient

• Neuroimaging in Epilepsy

• Role of CT & MRI in the Evaluation of Pathologies in Female Pelvis

• Imaging in Stroke

• Coronary CT Angiography

• Office Economics

CT Scan

Ultrasound MRI Imaging

Mammography

Vol. 9, Issue 3 & 4, April-September 20101

Vol. 9 Issue 3 & 4 April - September 2010

• Owned,Edited,PrintedandPublishedby Dr.VinayAggarwalforandonbehalfof

PushpanjaliMedicalPublicationsPvt.Ltd.,A-14,Pushpanjali,VikasMargExtn.,Delhi-110092

• PrintedatKumarOffsetPrinter,381,PatparganjIndustrialArea,Delhi-110092

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EDITOR SPEAKS

Editor-in-Chief Dr. Vinay Aggarwal

SectionalEditor Dr. Parveen Gulati

EditorialBoard

Dr. Vijay Agarwal Dr. Ashok Grover

Dr. Gaurav Aggarwal Atul Gandotra

Dr. Madhumita Puri Dr. Sharda Jain

Dr. B.K. Gupta Dr. Rajiv Gupta

Dr. S. Arul Rhaj Dr. Yogesh Jhamb

Dr. Neeraj Jain Mr. S.K. Singhal

DesignandLayout Ms.Tabassum

CONTENTS

1. NeuroimaginginEpilepsy 3

2. Imaginginstroke 7

3. CTCoronaryAngiography 15

4. RoleofCT&MRIintheEvaluationof 19

PathologiesintheFemalePelvis

5. AtimetoShapeUp 25

6. InitialManagementofPolytrauma 29

Patient

7. TransFats–TheTruth 35

8. OfficeErgonomics 39

9. EventsandInitiatives 45

10.Guidelinesforsubmissionof 51

manuscripts

We are fortunate to belong to an era of

unprecedented growth of scientific technology

as applied to medicine in general and medical

imaginginparticular.Eversincethediscoveryof

X-raysbyWilliamKRoentgenin1895,thescience

of radiology has shown tremendous progress.

Introduction of new diagnostic modalities like

USG,CT,Bonedensitometer,Mammographyand

MRI have revolutionized the field. Structural

imaging is no longer in two dimensions, and has evolved to imaging that

providesmultiplanarstructuralaswellfunctionalinformation.

Modernmedicalsciencehasmovedfromconventionalradiographytodigital

radiography, to 4D sonography with elastography, 256-slice CT and 3.0T

MRI that adds to the clinical information gathered by the specialist. The

introduction of interventional radiology has given a new face to this field

helpingthepatientaswellasclinicianinearlydiagnosisandtreatment.The

impactofthesenewadvancementscanbejudgedbythefactthatallformer

departments of Radiology are now christened as departments of Radiology

andImaging.

However, with so many options available to the practicing physicians and

surgeonsthatattimesthespecialistisinastateofdilemmaabouttheideal

imaging modality or an interventional procedure. This is especially true

with reference to two issues – degree of radiation exposure and financial

implicationsforthepatient.

Thepresentissuecoversfewofthecommonproblemsfacedinourday-to-day

practice.

Articlesonneuroimagingviz.,epilepsyandstrokehighlightedtheadvances

madeinthisrespectinrecentyearsandhowourperceptionandmanagement

ofthesepatientshaveundergoneseachangeswiththesemodalities,treating

a patient with stroke and without CT is something unimaginable now

consideringtheclinicalpitfalls.CTcoronaryangiographyissuchanaddition

totheinvestigativearmamentariumandtheutilityithasprovedinevaluating

atypical chest pain, post CABG status with chest pain is tremendous. The

clarityimagingprovidesinpolytraumapatientisremarkable.

Healthy life style, obesity and relief from it is delved into by Dr. Dinesh

Bhargava. A write up on Trans fats makes very interesting reading.

Physiotherapydepartment’sobservationsonofficeergonomics,oneneedsto

becarefulabout.

Dr. Parveen Gulati Head,Radiology&Imaging

PushpanjaliCrosslayHospital

Administrator

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Neuroimaging In Epilepsy

Shahina Bano and Sachchida Nand Yadav

A seizure is defined as a paroxysmal alteration

in neurologic function due to excessive

electrical discharge from the central nervous

system. Epilepsy is defined as a condition of

recurrent seizures, and medical intractability

as recurrent seizures despite optimal treatment

under the direction of an experienced

neurologist over a two to three year period.

Determining the underlying cause of a patient’s

seizure is the fundamental goal in the workup of

epilepsy. Imaging of the brain provides valuable

information in this regard. The main purposes

of neuroimaging in epilepsy patients are to

identify underlying structural or metabolic

abnormalities that require specific treatment

and to aid in formulating a syndromic or

etiologic diagnosis. Neuroimaging is even more

important for those patients who have medically

intractable seizures. Advances in technology to

localize epileptogenic focus, especially with

high resolution magnetic resonance imaging

(MRI), have substantially improved the success

of surgical treatment.

Common structural disorders associated

with seizure and detected on imaging can

be categorized into the following groups:

hippocampal or mesial temporal sclerosis,

cortical developmental malformations

or neuronal migration disorders (cortical

dysplasias, heterotopias, hemimegalencephaly,

lissencephaly, schizencephaly, pachygyria,

polymicrogyria, Rasmussen encephalitis),

phakomatoses (Tuberous sclerosis, Sturge

Weber syndrome, neurofibromatosis), vascular

abnormalities (arteriovenous malformation,

cavernous hemangiomas), infections

(Tuberculoma, neurocysticercosis), neoplasms

(ganglioglima, dysembryoplastic neuroepithelial

tumor, low grade gliomas and cerebral

metastasis in adults), stroke, posttraumatic

epilepsy, and miscellaneous conditions (gliosis,

encephalocele).

This article highlights the specific role of

various imaging modalities in patients with

epilepsy, and their practical applications in the

management of epileptic patients.

The major utility of computed tomography (CT)

scanning is in the initial evaluation of seizures,

particularly in trauma, hemorrhage, infarction,

tumors, calcified lesions and major structural

changes. In perioperative patients, it is the

imaging technique of choice as it can detect

the bleed, hydrocephalus and asses electrode

placement. However, the overall sensitivity of

CT in patients with epilepsy is low (~ 30%),

and because of poor resolution in the temporal

fossa CT is of no use in detecting mesial

temporal sclerosis, the most common pathology

in intractable temporal lobe epilepsy.1

Magnetic resonance imaging (MRI), with its

excellent spatial resolution, soft tissue contrast,

and multiplanar capabilities, is the imaging

modality of choice in investigating patients

with seizure disorder. The sensitivity of MRI

in identifying epileptogenic foci in patients

with medically refractory patients has been

reported to be more than 80%. However, in

patients with idiopathic generalized epilepsy,

MRI has not been shown to be useful. The

correlation of the MRI finding with clinical

and electroencephalography (EEG) findings are

essential to avoid false positive localization of

epileptogenic focus.2

Routine scanning protocol for a patient with

refractory epilepsy may include axial or coronal

T1 and T2-weighted imaging, Fluid-attenuated

inversion recovery (FLAIR) imaging, and 3D

volume acquisition sequences. Common 3D

acquisition sequences include high resolution

T1-weighted magnetization prepared rapid

acquisition gradient echo (MPRAGE) and fast

spoiled GRASS(3D-FSPGR), where GRASS is

gradient recalled echo acquisition at steady

state. T1-weighted sequences are used to

define the brain anatomy, and T2-weighted

or FLAIR sequences are used to detect the

brain pathologies. High-resolution 3D volume

acquisition provides good T1-weighted contrast

between gray and white matter and helps to

detect subtle cortical dysplasias and internal

structure of hippocampus in case of mesial

temporal sclerosis.3,4,5 For optimal assessment

Shahina Bano Consultant RadiologistRML HospitalDelhi

Sachchida Nand YadavConsultant RadiologistRML HospitalDelhi


of hippocampus the imaging should be in hippocampal axis

(oblique coronal plane) with thin slices and good signal-to-

noise ratio. The application of contrast agent is indicated if

there is suspicious of primary or metastatic tumor, infection, or

inflammatory lesion.

The specialized protocol includes Quantitative volumetry and T2

relaxometry, MR spectroscopy, Functional MRI (fMRI), Diffusion

weighted imaging (DWI) & Diffusion tensor imaging (DTI), and

Magnetic source imaging (MSI).

High resolution T1-weighted 3D volume gradient echo sequences

are also used for quantitative measurement of volume of any

particular region of interest. In the case of epilepsy this is usually

the hippocampus. Volumetric analysis of the hippocampus

can be performed both in adults and children with epilepsy,

to detect more subtle volume deficits (atrophy) that may be

missed by visual assessment alone. Volumetric measurements

can be performed manually or with half-or fully-automated

software, however, needs good knowledge of anatomical

details. Longitudinal studies done to asses the progression

of volumetric changes correlate with the seizure associated

damage.6 T2 relaxometry is the quantitative determinant of the

T2 relaxation time. To achieve this, several T2-weighted images

are acquired at different echo times, and with these values an

exponential decay curve is obtained to estimates the T2 decay

rate of the imaged tissue. The tissues that have prolonged T2 are

considered abnormal. In epileptic patients with hippocampal

sclerosis, signal increase on T2-weighted images is typically

observed in the hippocampus. The measured values of the

hippocampal volume and the T2 times are correlated with each

other, indicating that a marked volume loss is associated with

a significant increase in T2 relaxation, reflecting the complex

pathology of hippocampal sclerosis. 7

Proton MR spectroscopy (MRS) has proven to be a sensitive

measure to detect metabolic dysfunction in patients with

temporal lobe epilepsy (TLE), particularly mesial temporal

sclerosis (MTS) involving hippocampus. 20% of patients with

TLE have normal structural MRI scan and the findings in

children generally tend to be more subtle than those in adults.

MRS metabolite abnormalities may be found even in the absence

of detectable structural abnormalities. NAA, NAA/Cho, NAA/Cr,

and NAA/(Cho+Cr) all are decreased in atrophic hippocampi, as

well as in nonatrophic hippocampi with abnormal EEG findings.

Reduced N-acetylaspartate concentration suggests neuronal loss

or dysfunction. TLE patients may also show increased choline

and myoinositol signals, suggestive of gliosis. Studies of patients

during or immediately after seizures (within 6 hours) may also

show lactate increase in the epiletogenic focus. MRS also has

promising role in the evaluation of patients with extratemporal

epilepsy (frontal lobe epilepsy).8,9 In patients with structural

MR evidence of malformations of cortical development (MCD)

or neuronal migration disorders (NMD), MRS provides insight

into both the pathology and true extent of the disease processes.

Abnormally decreased NAA/Cr and Cho/Cr ratios have been

noted in these lesions, as well as in the normal appearing

brain contralateral to the lesion, when compared with gray and

white matter of neurologic controls.10,11 MRS is of particular

importance in patients with brain tumors. The characteristic

elevation of choline makes MRS a valuable tool for the diagnosis

of tumors and their differentiation from other lesions. There is

also evidence that MRS can differentiate between tumor types.12

Neurotransmitter MRS studies have potential therapeutic impact

in seizure patients. Glutamate and γ amino-butyric-acid(GABA)

can be measured using MRS editing techniques. Intracellular

glutamate concentrations remain elevated in the epileptogenic

hippocampus and neocortex, and contribute to the epileptic

state by increasing cellular excitability. 13

Surgical treatment of refractory focal seizure has been an important

and effective means for seizure control. However, the surgical

outcome is dependant on precise localization of epiletogenic

focus and functional areas of the brain. The functional MRI

(fMRI), plays a very important role in preoperative localization

of epileptogenic focus and assessment of cognitive function in

patients with refractory epilepsy. During focal seizure, cerebral

blood flow and metabolism is considerably increased. fMRI using

blood oxygen level dependent (BOLD) technique can detect

these cerebral hemodynamic changes. The excellent spatial

resolution of fMRI helps to study cortical activation during

epileptic activity and define epiletogenic focus in originally

activated area. The recent development of EEG-triggered fMRI

which allows interpretable electroencephalographic data to be

recorded during MRI scanning, has advantage of combining the

spatial resolution of imaging with the temporal resolution of

electrophysiology in precise localization of seizure foci, thus

increasing the rate of successful resection of the epileptogenic

focus. The EEG-triggered fMRI is highly reliable, repeatable and

noninvasive tool in localization of the seizure foci of patients

with intractable focal seizure. Combined video-EEG and fMRI in

localization of seizure foci has also shown good results.14,15 Long

term epileptic activity in patients with epilepsy results in atypical

distribution of cognitive function areas because of reorganization

of cortical language and memory areas. Accurate localization of

cognitive functional areas is necessary, to avoid their resection

at the time of surgery, to modify surgical approaches for those

patients at risk of language and memory deficit and to predict

postoperative cognitive deficit after resection of seizure foci.16

The diffusion-weighted signal reflects the molecular motion of

water in the intra-and extra-cellular environments. In tissue

components such as CSF, molecular motion is not restricted

in any direction and is known as isotropic diffusion, detected

by diffusion weighted imaging (DWI). In tissues with linear

arrangement of myelinated fibers such as white matter tracts, the

molecular motion is restricted to the axis along the white tracts

and is known as anisotropic diffusion, detected by diffusion

tensor imaging (DTI) or tractography. In epilepsy, DWI is used

to asses acute cerebral ischemia, tumors or infections, while

DTI has been used to assess the degree of distortion of white

matter tracts in case of developmental abnormalities and other

Vol. 9, Issue 3 & 4, April-September 2010�

References

1. Gastaut H, Gastaut JL. Computerized transverse axial

tomography in epilepsy. Epilepsia 17:325-336,1976.

2. Berg AT, Shinnar S. The risk of seizure recurrence

following a first unprovoked seizure: a quantitative review.

Neurology1991; 41:965-972.

3. Ruggieri PM, Najm IM. MR imaging in epilepsy. Neurol Clin

2001;19:477-89.

4. Raybound C, Guye M, Mancini J, Girard N. Neuroimaging

of epilepsy in children. Magn Reson Imaging Clin N Am

2001;9:121-47.

5. Barkovich AJ, Kuzniecky RI, Jackson GD, Guerrini R, Dobyns

WB. Classification system for malformations of cortical

development. Update 2001. Neurology 2002;57:2168-78.

6. Cook MJ, Fish DR, Shoryon SD, Straughan K, Stevens JM.

Hippocampal volumetric and morphometric studies in

frontal and temporal lobe epilepsy. Brain 1992; 115:

1001-15.

7. Van paesschen W, Connelly A, King MD, Jackson GD,

Duncan JS. The spectrum of hippocampal sclerosis. A

quantitative magnetic resonance imaging study. Ann

Neurol 1997;41:41-51.

8. Danielsen ER, Ross B. The clinical significance of

metabolites. In: Danielsen ER, Ross B, eds. Magnetic

resonance spectroscopy of Neurological Disease. New

York: Marcel Dekker inc, 1999:23-42.

9. Kuzniecky R, Palmer C, Hugg J, et al. Magnetic resonance

spectroscopic Imaging in temporal lobe epilepsy:

neuronal dysfunction or cell loss? Arch Neurol 2001;

58:2048-53.

10. Li LM, Cendes F, Bastos AC, et al: Neuronal metabolic

dysfunction in patients with cortical developmental

malformations: A proton magnetic resonance

spectroscopic imaging study. Neurology 50:755-759,

1998.

11. Simone IL, Federico F, Tortorella C, et al: Metabolic

changes in neuronal migration disorders: Evaluation by

combined MRI and proton MR spectroscopy. Epilepsa

40:872-879,1999.

12. Burtscher IM, Holtas S. Proton magnetic resonance

spectroscopy in brain tumors: clinical applications.

Neuroradiology 2001;43:345-352.

13. Petroff O. GABA and glutamate in the human brain.

Neuroscientist 2002;8:562-573.

14. YU AH, Piao CK, Li KC. Progress of functional MRI in

epilepsy. Clin Radiol(Chin) 2005;24:270-272.

15. Al asmi A, Benar CG, Gross DW, et al. fMRI activation

in continous and spike triggered EEG-fMRIstudies of

epileptic spikes. Epilepsia 2003;44:1328-1330.

16. Zhang L, Jin Z, Zeng YW, et al. Preoperative

brain functional mapping using fMRI in patients

with intractable epilepsy. Chin J sterotact Funct

Neurosurg(Chin) 2004;17:257-261.

17. Romero JM, Schaefer PW, Grant PE, Becerra L, Gonzalez

RG. Diffusion MR imaging of acute ischemic stroke.

Neuro Imaging Clin N Am 2002;12:35-53.

18. Rugg-Gunn FJ, Eriksson SH, Symms MR, Barker GJ,

Duncan JS. Diffusion tensor imaging of cryptogenic and

acquired partial epilepsies. Brain 2001;124:627-36.

19. Gallen CC, Hirschkoff EC, Buchann DS.

Magnetoencephalography and magnetic source imaging.

Capabilities and limitations. Neuroimaging Clin N Am

1995;5:227-249.

20. Chugani DC, Chugani HT. new directions in PET

neuroimaging for neocortical epilepsy. Adv Neurol 2000;

84:447-456.

21. Zubal IG, Spencer SS, Imam k, Seibyl J, Smith EO,

Wisniewski G, Hoffer PB. Difference images calculated

from ictal and interictal technetium-99m-HMPAO

SPECT scans of epilepsy. J Nucl Med 1995;36:684-689.

lesions responsible for seizure. Anisotropy is reduced in areas of

structural abnormalities suggesting structural disorganization of

white matter.17,18

Magnetoencephalography (MEG), also known as MSI when

combined with structural imaging, has proved to be new

noninvasive tool for localization of epileptic focus. MSI is similar

to EEG, but unlike EEG it detects magnetic rather than electric

signal and is more accurate for localizing abnormal focus. It is

increasingly useful for presurgical localization of epileptogenic

lesions and stimulus induced normal neuronal function to

minimize postoperative neurological deficits.19

Besides purely structural imaging techniques like MRI,

functional imaging studies like interictal positron emission

tomography (PET), and ictal and interictal single photon

emission computed tomography (SPECT) may provide additional

information in some patients and thus aid in clinical decision

making. PET and SPECT are usually not indicated for the majority

of patients with epilepsy but has important role in the surgical

candidates. The detection of cryptogenic lesions is the main goals

of functional epilepsy imaging with PET or SPECT. PET utilizes

an injection of tracer 18F- labeled deoxyglucose (18 FDG) to

measure brain metabolism. Interictal PET shows hypometabolism

in the seizure focus, especially in TLE. Ictal PET is not practical

due to extremely short half life of the radiotracers used. PET

remains a diagnostic modality for presurgical localization of

the focus in temporal lobe and extratemporal epilepsy when

MRI is normal.20 SPECT utilizes injection of radio-labeled

tracer Technetium99m hexamethyl-propyleneamineoxime (Tc-

HMPAO) or ethyl cysteinate dimmer(Tc ECD), which has very

slow distribution once in the brain. The tracer is stable for several

hours, allowing delayed imaging. The most useful study for

presurgical evaluation is an ictal SPECT, which usually reveals

increased blood flow at site of seizure onset. Interictal studies

often show relative hypoperfusion at the site of seizure onset.

The substraction of the interictal from the ictal SPECT, and then

coregistration of the resulting images onto MRI (substraction

ictal SPECT coregistration MRI - SISCOM) has shown to increase

the accuracy of this method.


Imaging in Stroke

Mohit Bhargava

IntroductionStroke is a medical emergency and is a consequence of compromised blood supply to the brain. Normal blood flow to the brain is approximately 50 ml per 100 grams brain tissue per minute, if the blood supply is < 18 ml per 100 grams brain tissue per minute spontaneous and evoked electrical activity ceases, resulting in a focal neurologic deficit. If ischemia persists for more than 30 minutes cytotoxic edema sets in irreversible damage starts in 30-60 minutes if blood supply is reduced by 40% or more

Etiologies:ThromboembolismIntracranial hemorrhageSystemic hypotensionVenous dural sinus thrombosisVasculitides

PathogenesisRegardless of the cause, neuronal ischemia initiates a complex chain of metabolic events culminating in death of the tissue in the involved area. There is rapid depletion of intracellular adenosine triphosphate (ATP), which leads to failure of the membrane-bound ATP-dependent ionic channels responsible for both neuron resting membrane potentials as well as generation of action potentials. This metabolic aberration results in accumulation of intracellular ions (including calcium ions), creating an intracellular gradient responsible for intracellular accumulation of water (ie, cytotoxic edema).

Cerebral endothelial cells are more resistant to ischemia than are neurons and neuroglial cells. About 3-4 hours after the onset of ischemia, the integrity of the blood-brain barrier becomes compromised, and plasma proteins are able to pass into the extracellular space. The intravascular water follows when reperfusion occurs (vasogenic edema); this process begins 3-6 hours after the onset of stroke and reaches a maximum 2-4 days after the onset of stroke; edema may extend into the white matter.

Depending on the size and type of vessel involved, there may be a central core of irreversibly damaged tissue; with presence of collateral circulation resulting in a rim of

damaged but still viable tissue in the lesion.

This area, called the penumbra, can be salvaged

provided the cerebral blood flow is restored

in time. By 24-48 hours, reparative process

begins at the periphery of the ischemic area and

proceeds centrally.

The necrotic tissue (damaged by ischemia) is

eventually removed by macrophages and is

replaced by remnant cysts and cavities along

with glial scar tissue. Reperfusion can also be

accompanied by hemorrhagic transformation of

the infarct, which is usually related to the volume

and site of the infarct, being more common in

large cortical infarcts. Encephalomalacia and

loss of volume in the affected region ensue

within weeks.

Why imaging?

According to Rowley, [1] the imaging of stroke

involves the evaluation of four ‘P’s (parenchyma,

pipes (cerebral vessels), perfusion, and

penumbra.)

Imaging helps in detection of the ischemia,

assessing the probable cause and extent of

parenchymal involvement, identify reversibly

or irreversibly damaged areas and to assess the

effect of ischmia on brain; and also to detect

early complication of stroke (e.g. cerebral

herniation, Hemorrhagic transformation, etc)

Imaging also helps in differentiating ischaemic

stroke from intracranial hemorrhage, and in

detecting structural lesions mimicking stroke

(like tumors, AVM, SDH, etc)

Stroke imaging is essential for planning

management strategy as it confirms the

occurrence of a stroke and, secondly is also

necessary for prognostication by assessing the

amount of potentially salvageable brain tissue

and irreversibly infarcted tissue. CT perfusion

and MR perfusion have been successfully

employed to assess the extent of salvageable

tissue as they define and differentiate between

the infarcted core and the ischemic penumbra,

so that measures can be taken to reverse the

ischemic changes and salvage as much brain

tissue as possible.

Mohit BhargavaConsultant RadiologistDept. of Radiology & ImagingPushpanjali Crosslay HospitalVaishali, Ghaziabad (NCR)


It is important to understand the meaning of potentially salvageable tissue. Whenever there is a decrease in the flow of blood to a particular area of the brain, collateral supply from the leptomeningeal vessels and from normal surrounding vessels tries to compensate. This results in a central area, the infarct, which receives little or no blood supply and a larger peripheral area where autoregulatory compensation tries to ensure the maintenance of adequate blood supply. This peripheral area is potentially salvageable by thrombolytic therapy and is called the ‘penumbra.’ [2],[3]

The limitation of an NCCT scan is that up to 40% of stroke patients have a normal scan in the first few hours and even if some of the subtle signs enumerated above are present, the observer may still miss them. [4] MRI imaging, especially diffusion-weighted imaging (DWI), scores over CT scan in this respect as DWI is very sensitive in detecting early ischemia and can detect changes as early as 20 min after the onset of stroke. [5],[6]1. CT angiography is an advanced application of present-day

multislice spiral CT scan machines. 2. MR angiography scores over CT angiography as it is possible

to evaluate both intracranial and extracranial arteries with and without injecting iv contrast

3. MR venography enables evaluation of cerebral veins and dural venous sinuses without injecting iv contrast

Types of infarction Broadly, stroke can be classified into two categories: ischemic and hemorrhagic. The former accounts for an estimated 80-85% of cases; the rest are hemorrhagic.[7] Stroke is a leading cause of death in developed countries and one of the most common causes of long-standing disability.

Atherosclerosis of the carotid arteries is by far the most common predisposing condition for stroke.

Thromboembolic infarction: This is the most common form of infarction. Typically, it is observed on MRI as a wedge-shaped infarct in the particular vascular distribution. Recent data support the hypothesis that a single infarct in a vascular territory is more likely to be thrombotic than multiple infarcts, which are more likely to be embolic.

Watershed infarction: This type of infarction occurs at the distal margins of specific arterial territories. It can occur both superficially and deep in the brain parenchyma. Common etiologies for this lesion include hypotension, cardiac and respiratory arrest, and proximal arterial stenosis or occlusion. MRI findings follow the pattern of incomplete thromboembolic ischemic infarction in T1 and T2 morphologic and signal changes, with early parenchymal enhancement suggesting early reperfusion. Recent studies show that this type of infarction could be more readily detected by using DWI.

Lacunar infarction: These are small deep cerebral infarctions believed to be caused by intrinsic small-vessel disease secondary to lipohyalinosis and fibrinoid necrosis; they are most frequently observed in patients with hypertension or diabetes mellitus. Common sites for these lesions include basal ganglia, internal

capsule, thalamus, brain stem, and cerebellum. MRI findings in

these lesions follow the same pattern observed in thromboembolic

infarction.

Venous thrombosis and infarction: Occlusion of cerebral veins

and venous sinuses is usually caused by systemic conditions,

such as pregnancy, collagen vascular diseases, inflammatory

bowel diseases, and hypercoagulable states, as well as local

conditions such as infection, neoplasia, and trauma. Occlusion

of the venous structure causes outflow obstruction and

vascular congestion that result in parenchymal infarctions and

hemorrhages.

Patients usually present in the late acute phase or in the subacute

phase, which makes the diagnosis difficult because diagnosis

at these stages depends on imaging studies. MRI findings in

these lesions include loss of venous flow void signal, absence of

normal venous enhancement, and visualization of isointense to

hyperintense signals within the venous channels on both T1 and

T2 images. These variable patterns of enhancement are due to

mixed blood products, which are present in the lesion.

These patterns are usually bilateral, do not respect arterial

vascular territories, and have associated hemorrhage.

Three-dimensional phase contrast magnetic resonance

venography (MRV) is the preferred technique in the evaluation

of venous thrombosis.

Ischemic Infarct

Features on CT scan:

Hyperacute stage: Changes seen on CT are due to cytotoxic

edema. There is decreased density of grey matter in the ischemic

zone, loss of grey-white matter differentiation, effacement /

obliteration of adjacent sulci (these lead to the “insular ribbon

sign” and obscuration of lentiform nuclei in MCA infarcts), and

mass effect may be present.

Acute stage: Early (acute) thrombus in the affected MCA results

in relative hyperdensity compared to the contralateral MCA

(Hyperdense MCA sign). During the next few days density of the

infracted tissue decreases, mass effect increases and both grey &

white matter may show changes.

Subacute stage: The ischemic area becomes isodense to normal

brain. This is called the “fogging effect”

Chronic stage: Encepahlomalacia with loss of volume ensues

CT perfusion helps in predicting the stroke location, stroke

size, reduction in cerebral blood flow volume (predicts absence

of vascular collaterals and thus the possibility of eventual

infarction) [8]

MRI perfusion and diffusion imaging provide similar information

with greater sensitivity and specificity. However, there are certain

inherent advantages of CT scan-based imaging. CT scan is more

widely available as compared to MRI and thus imaging can be

done earlier. It is relatively less expensive. Also, evaluation of

the carotids, intracerebral vessels, and cerebral perfusion can

be done in a very short time (approximately 5 min) The major

disadvantage of CT scan is the exposure to ionizing radiation


The American Heart Association has provided certain guidelines and recommendations for imaging of cerebral ischemia. According to these guidelines, quantitative CTP may probably be useful to differentiate between reversible and irreversible ischemic tissue in acute stroke patients. On the other hand, MRI perfusion and diffusion techniques are probably useful in differentiating between reversible and irreversible ischemic tissue in acute stroke patients [15] Thus, both techniques may be used, although at present MRI perfusion has more evidence in its favor.

Features on MRI:Acute stage: There is absence of normally visualized flow void in affected vessel. Altered signal intensity is seen, appearing hyperintense on T2W images – the findings may limited to grey matter in initial few hours; and may be associated with loss of grey white matter differentiation and a subtle mass effect. Hypointense areas may be seen in the subcortical white matter on T2W images. Arterial enhancement may be seen, especially in the area showing altered signalSubacute stage: Signal alteration and mass effect become more prominent. Fogging effect may be seen; prominent parenchymal enhancement may be seen, along with intravascular and overlying meningeal enhancementChronic stage: Encephalomalacia and cortical laminar necrosis are seen.

Diffusion Weighted Imaging: DWI is sensitive to the microscopic random motion of the water molecule protons, a value known as the apparent diffusion coefficient (ADC), which is measured and captured by this type of imaging. Numerous studies have shown that ADCs in ischemic areas are lower by 50% or more than those of normal brain areas, and they appear as bright areas (ie, hyperintensities) on the DWI

The technique most commonly used to acquire the DWI is an ultrafast one, echo-planar imaging (EPI); this technique decreases scanning time significantly and eliminates movement artifacts.The acute drop in ADC is gradually normalized to baseline at 5-10 days after ischemia (pseudonormalization); it even exceeds normal levels as time passes, helping in some cases to differentiate between acute, subacute, and chronic lesions.

DWI is very sensitive and relatively specific in detecting acute ischemic stroke. DWI findings have shown high levels of diagnostic accuracy; however, recent studies demonstrated that small brainstem lacunar infarctions may escape detection. Normal DWI in patients with stroke-like symptoms should trigger further investigation for a nonischemic cause of the symptoms. DWI has been shown to reveal diffusion abnormalities in almost 50% of patients with clinically defined transient ischemic attacks (TIAs); it tends to be of higher yield at increasing time intervals from the onset of stroke symptoms

Studies have demonstrated that changes in the ADC occur as early as 10 minutes following onset of ischemia. Cytotoxic edema appears following sodium/potassium pump failure, which results from energy metabolism failure due to ischemic insult; this

occurs within minutes of the onset of ischemia and produces an increase in brain tissue water of up to 3-5%. Reduction in intracellular and extracellular water molecule movement is the presumed explanation for the drop in ADC values.

ADC values are measured in several directions (3, 6, or more), and ADC maps are created to produce a direction-insensitive measurement of the diffusion. When ADC is measured in 6 or more directions, the diffusion motion of all the water molecules (ie, ADC tensor matrix) can be calculated to create what is called full diffusion tensor mapping, which can also be used to visualize white matter tracts.

Reduction in the ADC also occurs in other conditions such as global ischemia, hypoglycemia, and status epilepticus; it should always be evaluated in relation to the clinical condition of the patient.

Perfusion MRThis uses rapid MR pulse sequences after injecting iv contrast With this technique, information about the perfusion status of the brain is available. The most commonly used technique is bolus-contrast tracking (other techniques include blood oxygen level and arterial spin tagging). The imaging is based on the monitoring of a nondiffusible contrast material (gadolinium) passing through brain tissue.

The signal intensity declines as contrast material passes through the infarcted area and returns to normal as it exits this area. A curve is derived from this tracing data (ie, signal washout curve), which represents and estimates the cerebral blood volume (CBV). Quantitative maps of cerebral blood flow (CBF), CBV, mean transit time (MTT), time to peak (TTP), and various other hemodynamic parameters can be obtained.

Combination of DW and perfusion MRIDWI and PWI together have been shown to be superior to conventional MRI both in early phases and also up to 48 hours after the onset of stroke [9]. Using both DWI and PWI is very important because together they provide information about location and extent of infarction within minutes of onset; when performed in series, they can provide information about the pattern of evolution of the ischemic lesion. This information may be of great importance in choosing the appropriate treatment modality as well as in predicting outcome and prognosis. Several recent randomized clinical trials are selecting patients with diffusion-perfusion mismatch to test thrombolytic treatment alternatives beyond the standard 3-hour time window used for iv TPA.

The lesion usually enlarges on serial DWIs over a period of several days. It has been suggested that this enlargement can be halted if reperfusion (i.e. resolution of original PWI lesion) occurs early enough. Lesions that are not large on initial PWI do not show this enlargement.

The diffusion-perfusion mismatch ie, the difference in size between lesions captured by DWI and PWI, usually represents the ischemic penumbra which is the region of incomplete


ischemia that lies next to the core of the infarction. The ischemic

penumbra is regarded as an area that is viable but under ischemic

threat; it can be saved if appropriate intervention is promptly

instituted. The viability of this region could extend up to 48

hours after the onset of stroke. Determining the volume of the

ischemic penumbra may be very useful in identifying patients

who would benefit from thrombolytic therapy and perhaps even

conventional treatments such as carotid endarterectomy or blood

pressure elevation. It could also aid in evaluating the risk/benefit

ratio of using such treatments in stroke patients.

DTI

More extended diffusion tensor imaging (DTI) scans derive

neural tract directional information from the data using 3D or

multidimensional vector algorithms based on three, six, or more

gradient directions, sufficient to compute the diffusion tensor.

The diffusion model is a rather simple model of the diffusion

process, assuming homogeneity and linearity of the diffusion

within each image voxel. From the diffusion tensor, diffusion

anisotropy measures such as the fractional anisotropy (FA), can

be computed. Moreover, the principal direction of the diffusion

tensor can be used to infer the white-matter connectivity of the

brain (ie, tractography - trying to see which part of the brain is

connected to which other part) [10].

Recently, more advanced models of the diffusion process have

been proposed that aim to overcome the weaknesses of the

diffusion tensor model

Traditionally, in diffusion-weighted imaging (DWI), three

gradient-directions are applied, sufficient to estimate the trace of

the diffusion tensor or ‘average diffusivity’, a putative measure

of edema. Clinically, trace-weighted images have proven to be

very useful to diagnose vascularstrokes in the brain, by early

detection (within a couple of minutes) of the hypoxic edema.

Limitations of diffusion-perfusion mismatch are mainly methodological and include (1) lack of anatomical match between diffusion and perfusion-weighted abnormality, (2) variable sensitivity of perfusion-weighted image based on Tmax

delay, (3) visual versus quantitative estimation of mismatch.

One limitation of these techniques is in detection of acute intracerebral hemorrhages; early studies demonstrated that susceptibility imaging could be sensitive in the detection of acute intracerebral hemorrhage. Gradient-recalled echo (GRE) monstrated the most favorable sensitivity in detecting susceptibility dephasing associated with chronic intracerebral hemorrhages.

MRI still has some limitations in its application, namely, in patients with metal implants and acutely ill patients requiring close monitoring.

These new techniques, DWI and PWI, together represent the most exciting areas in MRI for their potential ability to detect early changes (ie, within minutes of the stroke). They are currently used in the evaluation of thrombolytic and neuroprotective therapy in acute stroke clinical trials.

MRI findings in TIAA third to a half of the patients presenting with a TIA have lesions on DWI. A significant proportion of these patients may not reveal a corresponding lesion on T2-WI. PWI may be more sensitive but has not been adequately tested in patients with TIA. DWI-positive TIA lesions do necessarily show as infarction on follow-up MRI.

Although TIAs have been traditionally defined as transient (<24h) neurologic deficit of vascular origin, the advent of MRI has lead to reconsideration of the definition. Whether DWI- positive TIAs are to be regarded as stroke or TIA is unclear.

Magnetic resonance imaging in acute stroke: Diffusion-perfusion mismatch in acute ischemic stroke. The perfusion abnormality (right) is larger than the diffusion abnormality (left), indicating the ischemic penumbra, which is at risk of infarction. Courtesy: http://emedicine.medscape.com/article/1155506-media


MRI in hemorrhagic stroke

GRE and EPI sequences have the ability to detect microbleeds

that are clinically silent and not visualized by CT scanning or

routine MR sequences. These microbleeds are visualized in a fifth

to a quarter of patients with ischemic stroke and 5% of elderly

asymptomatic individuals. The microbleeds depict hemosiderin

deposit and have been histopathologically correlated with prior

extravasations of blood. These microbleeds may represent

bleeding-prone angiopathy and a higher rate of hemorrhagic

transformation from anticoagulation, antithrombotic, and

thrombolytic therapy.

GRE, EPI, and DWI (B0) are sensitive to detecting intraparenchymal

hemorrhage (primary intracerebral hemorrhage and hemorrhagic

transformation) in the hyperacute stages (first few hours),

whereas the conventional T1-WI and T2-WI are sensitive in

detecting subacute and chronic bleeding. FLAIR sequences may

have a role in detecting extra-axial collections of blood (subdural

hemorrhages). Routine T1W and T2W sequences are also used

to date the intra axial hemorrhage. Having stated the above, the

current guidelines do not advocate the use of MR in place of CT

scanning to screen patients for thrombolysis.

Follow Up

Further Inpatient Care

Inpatients may often continue to be monitored and receive

treatment while undergoing MRI because MRI-compatible ECG

monitors, intravenous infusion pumps, and ventilators are

available.

Inpatient and outpatient medications

A mild sedative may be ordered for patients with a history of

claustrophobia. As an alternative, an open MRI may be ordered

at the cost of lesser quality MR images.

Magnetic resonance imaging in acute stroke: Left: Diffusion-weighted MRI in acute ischemic stroke performed 35 minutes after symptom onset. Right: Apparent diffusion coefficient (ADC) map obtained from the same patient at the same time.Courtesy: http://emedicine.medscape.com/article/1155506-media

Magnetic resonance imaging in acute stroke:Left: Perfusion-weighted MRI of a patient who presented 1 hour after onset of stroke symptoms. Right: Mean transfer time (MTT) map of the same patient.Courtesy: http://emedicine.medscape.com/article/1155506-media

Magnetic resonance imaging in acute stroke: Diffusion-perfusion mismatch in acute ischemic stroke. The perfusion abnormality (right) is larger than the diffusion abnormality (left), indicating the ischemic penumbra, which is at risk of infarction.Courtesy: http://emedicine.medscape.com/article/1155506-media

Diffusion tensor imagingCourtesy: http://emedicine.medscape.com/article/1155506-media


Complications

Patients with metallic implants may have a variety of potential

complications, such as heating and pacemaker malfunction

and its consequences. For patients with a metallic implant,

checking with the manufacturer regarding its MR compatibility

is advisable if such information is not available elsewhere.

Claustrophobic patients may be unable to complete the sequence

of MRI. In selected patients, mild sedation or imaging in an open

MR system may be attempted. However, most open MR scanners

provide lesser quality images.

Rarely, patients may be allergic to the contrast agent (eg,

gadolinium) used in MRI.

Special Concerns

Patients who have received recent thrombolysis or are critically

ill from stroke are probably not well suited for MRI because they

cannot be monitored by clinical examinations during the period

of imaging. If MRI is essential, it should be performed with the

bare minimum of sequences required to make the diagnosis,

such as T1, T2, DWI or PWI, and MRA. Many institutions have

established acute stroke protocols to minimize scanning time.

Patients with acute stroke who are considered for MRI should be

evaluated for contraindications to MRI such as claustrophobia,

metallic implants, pacemakers, and MR-incompatible prosthetic

heart valves.

References1. Rowley HA. The four Ps of acute stroke imaging:

Parenchyma, pipes, perfusion, and penumbra. AJNR Am J Neuroradiol 2001;22:599-601.

2. Patrick D. Thrombolytic Therapy for Stroke. Lyden Humana Press; 2001. p. 44-7.

3. Fisher M. Characterizing the target of acute stroke treatment. Stroke 1997;28:866-72.

4. Von Kummer R, Bourquain H, Bastianello S, Bozzao L, Manelfe C, Meier D, et al . Early prediction of irreversible brain damage after ischemic stroke at CT. Radiology 2001;219:95-100.

5. HjortN,ChristensenS, SψllingC,AshkanianM,WuO,RψhlL,etal.Ischemicinjurydetectedbydiffusionimaging 11 minutes after stroke. Ann Neurol 2005;58: 462-5.

6. Crisostomo RA, Garcia MM, Tong DC. Detection of diffusion-weighted MRI abnormalities in patients with transient ischemic attack: Correlation with clinical characteristics. Stroke 2003;34:932-7.

7. Beauchamp NJ Jr, Barker PB, Wang PY, vanZijl PC. Imaging of acute cerebral ischemia. Radiology 1999;212:307-24.

8. Khandelwal N. CT perfusion in acute stroke. Indian J Radiol Imaging 2008;18:281-6

9. M.Luby, S.Warach. Reliability of MR Perfusion – Weighted and Diffusion Weighted Imaging Mismatch Measurement Methods. American Journal of Neuroradiology 28:1674-1678, October 2007

10. Filler, Aaron (2009). “MR Neurography and Diffusion Tensor Imaging: Origins, History & Clinical Impact”.

Neurosurgery 65(4 Suppl): 29–43.


CT Coronary Angiography

Shailender Chaturvedi

Introduction

Coronary artery disease is a common cause of

death in adults in this country. Coronary artery

disease is secondary to narrowing of the coronary

vessels from atherosclerosis. Injury to the

endothelium leads to an inflammatory reaction,

and there is accumulation of inflammatory

cells, smooth muscle cells, and fat deposits in

the vessel wall. These lead to formation of an

atherosclerotic plaque that narrows the lumen.

Risk factors are well known and include age,

male gender, lack of exercise, obesity, high blood

pressure, elevated blood lipid levels, smoking,

and diabetes.

Invasive coronary angiography (ICA) remains

the gold standard for the diagnosis and then

assessment of severity of coronary artery

stenoses. It also has the advantage of carrying

out therapeutic intervention at the same time.

However, it carries with it the complications of

the invasive procedure and the inconvenience

for the patient. Introduction of multidetector

technology made it possible to see coronaries

noninvasively, however the results were not

very acceptable. With further improvements

in CT technology and introduction of 64 slice

CT which provides increased spatial and

temporal resolution the results have been very

encouraging and presently it can be and is being

used for coronary evaluation with satisfying

results.

The main applications of coronary angiography

with multi–detector row CT are diagnosis of

anomalous origin of coronary, noncalcified

plaques, detection, quantification of coronary

artery stenoses, and follow-up after surgical

bypass therapy. Additional applications include

evaluation of myocardial perfusion, scarring,

and contractility. The key advantages of this

technique are the noninvasiveness of the study

and the ability to evaluate both the coronary

artery lumen and the vessel wall.

Challenges in evaluating the coronary arteries

at CT are the small size of the vessels and the

location adjacent to the moving heart. The

vessels are typically 2–4 mm in diameter and are

parallel, oblique, or perpendicular to the axial

plane in portions. In addition, they are adjacent

to both the atria and ventricles and therefore

may be affected by cardiac motion in different

phases of the cardiac cycle. Possible solutions

are imaging on scanners with an increasing

number of rows and faster rotation speeds and

reconstructing multiple sets of images obtained

in different phases of the cardiac cycle from a

volume acquisition.

The role of imaging is progressing from simple

determination of the presence of arterial

calcifications on nonenhanced scans to

demonstration of vascular stenoses on coronary

CT angiograms. Optimization of the imaging

technique and knowledge of coronary artery

anatomy are both important for the development

of CT of the heart. Technical factors such

as a slow heart rate, a short scanning time,

subcentimeter spatial resolution, high temporal

resolution, and reconstruction of multiple image

data sets at various intervals in the cardiac cycle

result in optimal visualization of the coronary

arteries. Axial, thin-slab maximum intensity

projection, and volume-rendered images

are used to display the normal anatomy and

anomalies of the coronary arteries.

Indication and contraindication

The main indications for coronary CT today

are: (1) Non specific chest pain to exclude

the cardiac cause (2) Screening for high risk

patients – patients with diabetes / hypertension

/ deranged lipid profile / strong family history

(3) Screening for anomalous origin of coronary

artery.

Conventional angiography remains the standard

in patients suspected of having acute coronary

syndromes, for which intervention is anticipated.

The confidence in predicting unstable plaque

and coronary events falls with increasing

atherosclerotic disease burden. Coronary CT

angiography is not performed in patients with

a heavy burden of calcified plaque because

estimating the degree of stenosis at the site of

calcified plaque will be difficult due to blooming

artifact and because a catheter angiogram will

Shailender Chaturvedi Consultant RadiologistDept. of Radiology & ImagingPushpanjali Crosslay HospitalVaishali, Ghaziabad (NCR)


still be necessary. Patients with a heart rate of more than 70 beats

per minute (bpm) or with significant arrhythmia are considered

unsuitable because the resulting images are poor. Breath-hold

difficulties and the inability to remain supine and motionless are

relative contraindications.

Patients with arrhythmia, allergy to iodinated contrast media,

and renal insufficiency (serum creatinine > 120 mmol/l) are not

suitable for the study.

Patient Preparation

The main preparation involves slowing the patient’s heart rate

to approximately 60 bpm because this lower heart rate increases

the relative proportion of the cardiac cycle spent in diastole and

limits motion artifact. Generally oral ß-blockers are prescribed

by the referring doctor 2–3 days before scanning and organized

at the time of scheduling. Some sites also give ß-blockers at the

time of the study as well.

Sample ß-blocker protocols include giving 50 mg of metoprolol

orally 1 hr before scanning or 5 mg of metoprolol IV a few

minutes before the study. Calcium channel blockers are used if

ß-blockers are contraindicated. Contraindications for ß-blocker

therapy include asthma, atrioventricular conduction block, heart

failure, diabetes, and Raynaud syndrome. Three ECG leads are

placed over the patient as specified by the manufacturer of the

scanner to obtain an ECG tracing on the scanner console.

Technique Summary

A 80-120-mL dose of nonionic iodinated contrast material is

injected intravenously at approximately 4 – 5 mL / sec for CT

angiography. A saline solution bolus is also given following

contrast material injection to decrease artifact from contrast

material in the right heart. Scanning is triggered once contrast

material is seen in the ascending aorta, or a test bolus is

administered to calculate the appropriate delay. Typical delays

in study are 10–18 seconds. Detector collimation, kilovolt peak,

pitch factor and matrix size optimisation is also crucial.

The images are reconstructed by using a medium soft-tissue

kernel with retrospective ECG gating. Multiple image sets are

reconstructed in diastole at variable relative delay. In general,

reconstruction is avoided at 10%–30% or greater than 80% of

the R-R interval, as these times are particularly susceptible to

motion artifacts.

Display of Multi–Detector Row CT Coronary Angiograms

Three-dimensional and multiplannar views are used to

supplement the axial CT images. Portions of all vessels, in

particular the left main artery and LAD artery, can be evaluated

on the axial images. Longer vessel segments are demonstrated on

curved multiplanar reformatted and three-dimensional volume-

rendered images. Calcifications and noncalcified plaques are

assessed on thin-slab maximum intensity projection and volume-

rendered images. Virtual angioscopic views are also possible.

In a study that compared axial, virtual angioscopic, volume-

rendered, and multiplanar reformatted images, the most stenoses

were seen on axial images followed by virtual angioscopic,

volume-rendered, and multiplanar reformatted images. Use of

all four techniques gave the highest sensitivity. A combination

of various viewing methods has been used in most studies. The

most effective method for reformation has still to be determined,

but thin-slab maximum intensity projection seems to be most

widely used.

Detection of coronary artery stenoses

The opportunity to non-invasively visualize coronary anatomy is

the major reason for the current interest in cardiac MDCT. With

the introduction of 64slice MDCT systems, improved temporal

and spatial resolution as well as substantially shorter scan times

led to improved image quality throughout the entire coronary

tree. Importantly, the technique may be most suitable as a non-

invasive tool to rule out significant CAD and avoid further

imaging or invasive angiography.

There is a tendency to overestimate the degree of luminal

narrowing by CT when compared with invasive angiography, and

pronounced calcification of a vessel segment can make lesion

assessment particularly difficult. Usually, calcification will lead

to overestimation, rather than underestimation of lesion severity.

Furthermore, coronary CT angiography is limited to the anatomic

visualization of stenoses and does not provide information as to

the functional relevance of a lesion. For this reason, although

64-slice MDCT is a reliable tool to rule out functionally relevant

CAD in a non-selected population with an intermediate pre-test

likelihood of disease, an abnormal coronary CT angiogram does

not necessarily predict ischemia.

The use of coronary CT angiography should be restricted to

patients in whom diagnostic image quality is achievable (e.g.

absence of arrhythmias), and scans need to be expertly performed

and interpreted.

Evaluation of Bypass Graft and Native Postanastomotic Coronary

Artery Patency

Conventional selective angiography is the standard for assessing

bypass graft patency after coronary artery bypass grafting

(CABG). It is an invasive and potentially harmful procedure with

a low risk of serious complications, such as conduit dissection,

spasm, embolization and myocardial infarction, arrhythmia,

stroke, and death.

Cardiac CT is a promising noninvasive measure to evaluate

patency of bypass conduits, including the gastroepiploic artery

where catheterization is usually difficult. The ability to display

the vessel wall as well as its lumen might distinguish radial artery

spasm from intimal hyperplasia. Knowledge about the patency

rate of various bypass grafts is valuable in the care of patients

undergoing surgical revascularization. The demonstrated

improved patency rate of internal mammary artery (IMA) grafts

over saphenous vein grafts, for example, changed the surgical

approach in the late 1980s, and many surgeons currently perform

multiple arterial grafting in daily practice.


Multidetector-row CT (MDCT) scanners have recently been

used for noninvasive imaging of coronary artery disease

and determining the patency of bypass grafts. In addition to

providing very good full-length visualization of conduits from

origin to distal anastomosis, the technique has the added

benefit of demonstrating the precise anatomy of the grafts

and surrounding structures, the conduit wall, and its lumen.

This allows differentiation between vessel spasm and various

intraluminal pathological conditions.

The images with submillimeter isotropic resolution and improved

temporal resolution have recently been shown to be highly

accurate in the detection of coronary artery stenoses. Another

advantage is the clear demonstration of ostial lesions, such as

ostial left main coronary artery disease, lesions that might be

missed with conventional coronary angiography because of

positioning of the catheter tip beyond the arterial ostium.

Assessment with multidetector computed tomography allows a

very accurate assessment of arterial and venous conduits and

of postanastomotic native coronary arteries in patients with

previous bypass graft. The leading cause of unfeasibility for

postanastomotic coronary arteries is the small diameter of the

examined vessel (<1.5 mm).

The MDCT is a feasible and accurate method for the detection

of patency and significant stenosis (more than 50% decrease in

diameter), not only of arterial and venous grafts (as demonstrated

in previous studies) but also of distal postanastomotic coronary

arteries.

Diagnosis of Coronary In-Stent Restenosis

A new generation MDCT scanner could diagnose or exclude

angiographic restenosis in the stented segment with a high

degree of certainty. The degree of ISR is evaluated both by visual

inspection and by intraluminal assessment of contrast density. A

number of factors like surrounding calcification, motion artifacts,

excessive radio-opacity of stent, and small size (underexpanded

stent 3.0 mm) affect the interpretation of MDCT scans of stented

segments. The diagnosis of total occlusion of a stented segment

on MDCT is more straightforward than partial obstruction.

Although in single, carefully selected cases (eg, large diameter

stents in a proximal vessel segment, low and stable heart rate,

and absence of excessive image noise) coronary CT angiography

may be a possibility to rule out in-stent restenosis, routine

application of CT to assess patients with coronary stents can

currently not be recommended.

Coronary Artery Anomalies

Although coronary anomalies are rare conditions, possible

consequences include myocardial infarction and sudden death.

In young athletes, coronary artery anomalies are the second

most common cause of sudden death due to structural heart

disease. The identification of the origin and course of aberrant

coronary arteries by invasive angiography can be difficult.

Because of the three-dimensional nature of the data set, MDCT

is very well suited to detect and define the anatomic course of

coronary artery anomalies and their relationship to other cardiac

and non-cardiac structures. CT analysis of coronary anatomy is

straightforward and very reliable with accuracy close to 100%.

The robust visualization and classification of anomalous

coronary arteries make CT angiography a first-choice imaging

modality for the investigation of known or suspected coronary

artery anomalies. Radiation dose must be considered often in

the young patients, and measures to keep dose as low as possible

must be employed.

Calcium scoringCoronary calcium is a surrogate marker for the presence and

amount of coronary atherosclerotic plaque. Both EBCT and

MDCT permit accurate detection and quantification of coronary

artery calcium. The so-called ‘Agatston Score’, which takes into

account the area and the CT density of calcified lesions, is most

frequently used to quantify the amount of coronary calcium in

CT, and large population reference databases are available.

Even the detection of large amounts of calcium does not indicate

the presence of significant stenoses and it should not prompt

invasive coronary angiography in otherwise asymptomatic

individuals.

Non-calcified plaque

There is growing interest concerning the ability of contrast-

enhanced CT coronary angiography to detect (and possibly to

quantify and to further characterize) non-calcified coronary

atherosclerotic plaque.

The tremendous potential of CT angiography for visualization

and characterization of coronary plaques must be recognized

and further research is strongly supported.

Conclusions

64-slice CT due to its high spatial and temporal resolution is an

excellent modality to evaluate coronaries non invasively. Still

existing limitations are the exclusion of patients with arrhythmia

and limiting factors such as strong vessel wall calcifications

and motion artefacts which all can cause a restricted image

interpretation. With further developments in the CT technology

and introduction of 256-slice the results are bound to improve

further. The present day indications of coronary CT are as

follows:

1. Patients with atypical or unclear thoracic symptoms

2. Screening for high risk patients

3. Preoperative planning: Exact localization of coronary arteries

in relation to surrounding structures and identification of

significant stenosis or vessel wall calcifications, as well as an

intramyocardial course of the arteries to plan and conduct the

surgical procedure. Similar to the coronary arteries, evaluation

of internal mammary arteries and ascending aorta for planning

the operation in terms of graft harvesting and cannulation site

can be performed in the same CT examination.

Similarly, morphologic abnormalities of the aortic and mitral

valve are feasible within the same CT examination to identify

and quantify calcifications or morphologic abnormalities.

4. Followup of patients with CABG / stent.


References

1. Schroeder S, Kopp AF, Baumbach A, Meisner C,

Kuettner A, Georg C, Ohnesorge B, Herdeg C, Claussen

CD, Karsch KR. Noninvasive detection and evaluation

of atherosclerotic coronary plaques with multislice

computed tomography. J Am Coll Cardiol

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Christensen, L. Kober, and C. Torp-Pedersen 64-

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We Do It—Data Acquisition, Postprocessing, Display,

and Interpretation Leo P. Lawler1, Harpreet K. Pannu and

Elliot K. Fishman. All authors: Department of Radiology

and Radiological Science, Johns Hopkins University, 601 N Caroline St., Rm. 3254, Baltimore, MD 21287-0801. Received February 12, 2004; accepted after revision September 15, 2004.

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9. Vogl TJ, Abolmaali ND, Diebold T, et al. Techniques for the detection of coronary atherosclerosis: multi-detector row CT coronary angiography Radiology 2002;223:212-220.

10. Nieman K, Oudkerk M, Rensing BJ, et al. Coronary angiography with multi-slice computed tomography Lancet 2001;357:599-603. Schroeder S, Kopp AF, Baumbach A, et al.

11. Noninvasive detection and evaluation of atherosclerotic coronary plaques with multislice computed tomography J Am Coll Cardiol 2001;37:1430-1435.

12. Nieman K, Pattynama PMT, Rensing BJ, van Geuns RJM, Feyter PJ. Evaluation of patients after coronary artery bypass surgery: CT angiographic assessment of grafts and coronary arteries Radiology 2003;229:749-756.

13. Achamnbach S, Moselewski F, Ropers D, et al. Detection of calcified and noncalcified coronary atherosclerotic plaque by contrast-enhanced submillimeter multidetector spiral computed tomography Circulation 2004;109:14-17.

14. Nikolau K, Rist C, Wintersperger B, et al. Clinical value of MDCT in the diagnosis of coronary artery disease in patients with a low pretest likelihood of significant disease AJR Am J Roentgenol 2006;186:1659-1668.

15. Mankind AH, Buecker A, Wildberger JA, et al. Coronary artery stents in multislice computed tomography. In vitro artifact evaluation Invest Radiol 2004;39:27-33.

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Parveen GulatiHead, Dept. of Radiology & Imaging Pushpanjali Crosslay HospitalVaishali, Ghaziabad (NCR)

Peeyush PanditConsultant RadiologistDept. of Radiology & Imaging Pushpanjali Crosslay HospitalVaishali, Ghaziabad (NCR)

Role of CT & MRI in the Evaluation of Pathologies in the Female Pelvis

Parveen Gulati and Peeyush Pandit

Normal Pelvic Anatomy

Uterine corpus

The normal position of the uterus varies widely. It is typically anteflexed and located centrally on the roof of the urinary bladder. Its size and perfusion vary during the menstrual cycle. The diameter of the uterus in women of reproductive age should not exceed 6 cm. Differentiation of the myometrium and endometrium by CT is not possible.

With MR imaging, the corpus uteri is characterized by relatively low signal intensity on T1-weighted MR images. On T2-weighted images, the high-signal-intensity endometrium can be distinguished from the myometrium, which has intermediate signal intensity. On these images, the two layers are separated by a hypointense band, the so-called junctional zone, for which there is no clear histomorphologic correlate. The size of the endometrium varies between 1 and 7 mm through the menstrual cycle. In the postmenopausal uterus, these 3 zones are no longer discernible on T2-weighted images. The postmenopausal endometrium has a maximal thickness of 3-5 mm. Cervix and Vagina

On CT scans, the cervix/corpus junction is discernible only at the isthmus of the organ. The cervix appears as a roundish to transverse oval structure with a maximum diameter of 3 cm. The cervix or cervical canal is occasionally seen as a central hypointense zone. On MRI, the cervix is characterized by a low signal intensity on T1 and T2-weighted images due to its high proportion of fibrous tissue. A central high-signal-intensity layer on T2-images corresponds to the epithelial and mucosal coat of the cervical canal. T2-weighted sequences allow a clear identification of the anterior and posterior vaginal layers, which are both of low signal intensity, as well as of the ventrally located urethra and the dorsally situated rectum.

Parametrium

The parametria are the spaces between the layers of the broad ligament extending form the side of the uterus to the wall of the pelvis. CT only visualizes the round and broad ligaments and occasionally the adnexa and ovaries.

With MR imaging, the normal parametrial connective tissue can best be evaluated on T1-weighted axial images, on which it is

distinguished from the hyperintense surrounding fatty tissue by its intermediate signal intensity. It shows moderate enhancement after application of Gd-DTPA.

Ovaries

The ovaries in women of reproductive age have a size of about 3-5 cm x 1.5-3 cm x 0.6-1.5 cm. Due to physiological atrophy; the postmenopausal ovaries are difficult to differentiate from surrounding structures.

The advantages of CT Include its high spatial resolution and the absence of motion artifacts, while the radiation exposure is a major drawback, particularly in younger women, CT allows a good differentiation of cystic and solid tumors. The densities of cysts may reach rather high densities, but it is not always possible to differentiate them form solid lesions, whereas fat-containing teratomas (dermoid cysts) are easy to diagnose. The differentiation of benign from malignant ovarian tumors by both CT and MR imaging is based on morphologic criteria. Due to its high special resolution, CT offers good visualization of these morphologic features.

On T1-weighted images, the normal ovary is characterized by a low signal intensity and isointensity with muscle or uterine tissue. On T2-weighted images, the ovaries have a signal intensity equivalent to that of fatty tissue and show areas of higher signal intensity corresponding to small cysts. The main advantage of MR imaging in the diagnostic evaluation of ovarian tumors is the high soft-tissue contrast, while the ability to freely orient the imaging plane is less important. Both cystic and solid lesions of the ovaries can be reliable delineated from the uterus, since the latter is distinguished by the high-signal-intensity endometrium and the low-signal-intensity myometrium on T2 –weighted images. Especially large masses in the true pelvis may be difficult to differentiate by CT.

Congenital Anomalies

Congenital Anomalies fall into two major categories: a) Atresia and aplasia of uterus and vagina.b) Anomalies due to incomplete fusion or

failure of reabsorption of the mullerian ducts.

MRI is the imaging modality of choice for the evaluation of complete or partial vaginal agenesis: One can also demonstrate


the presence or absence of functional endometrium and cervix on MRI. This information is important for patient counseling regarding reproductive capability.

Uterine agenesis or hypoplasia: T2 – weighted sagittal images are best for determining the presence or absence of a uterus. There is no identifiable uterine tissue on MR images in uterine agenesis. In uterine hypoplasia, the endometrial cavity is small with a reduced intercornual diameter (less than 2 cm). Unicornuate uterus: The MRI appearance of unicornuate uterus is the elongated banana shape. MRI is more accurate than endo-vaginal Ultrasound (EVUS) for diagnosing the unicornuate uterus.

Didelphys uterus (nonfusion of mullerian ducts): The MRI appearance is of two separate nominal sized uteri and cervices with a septum extending into upper vagina. The two uterine horns are usually widely separated and the endometrial and myometrial width are preserved. Rarely, separate hemiuteri with completely separate vagina, with two vaginal orifices can be seen.

Bicornuate uterus (partial failure of mullerian duct fusion): The division may extend to the external os (uterus bicornuate bicollis) or to the internal os (uterus bicornuate unicollis). On MRI scans, the inter cornual distance is increased and there is an outward fundal concavity compared with the normal convexity. In arcuate uterus, the fundal surface is flattened or slightly concave, with a heart-shaped endometrial cavity. Hematosalpix or hematometra can develop in any uterine anomaly. MRI will demonstrate a dilated uterine horn distended with material showing signal intensity consistent with hemorrhage. Septate uterus (Failure of resorption of the final fibrous septum between the mullerian duct components): Septate uteri cause more frequent reproductive problems than bicornuate uteri, and are repaired by different surgical procedures. The septum is composed mainly of fibrous tissue, showing low signal intensity on T2 weighted images. If septum reaches to internal os, it is complete and if it terminates above the internal os, it is partial. The fundal contour on MRI is usually normal with an outward fundal convexity, differentiating it from bicornuate uterus.

Accurate differentiation between the septate and bicornuate uterus is extremely important for patient management. The septate uterus is associated with higher rate of reproductive failure but can be repaired by hysteroscopic metroplasty. The bicornuate uterus which is a less often cause of fetal loss is repaired by a trans abdominal approach because of risk of perforating the myometrium. Uterine anomalies have been reported to be present in up to 50% of cases exposed in utero to DES (synthetic estrogen). Associated anomalies include hypoplasia, T-shaped uterus, contractions and marginal irregularities of endometrial cavity and result in an increased incidence of early reproductive loss.

MRI may also be useful in evaluating patients with ambiguous genitalia. These patients are at a higher risk for gonadal tumors and may require radiologic evaluation.

Uterine Tumors

Adenomyosis: This is the presence of heterotopic endometrium within the myometrium. There are two forms of adenomyosis, a diffuse and a focal type.• Diffuse type: On MRI images, the low signal intensity

junctional zone is increased in thickness to varying degrees. Use of a junctional zone thickness of 12mm or more results in a high MRI accuracy in detection of adenomyosis. In some patients, high signal intensity foci can be detected within the thickened junctional zone on both T1W and T2W images, thought to represent hemorrhage.

• Focal type: This is seen as a mass of low signal intensity that appears similar to a leiomyoma and is sometimes called an adenomyoma. Differentiation between leiomyomas and focal adenomyosis is of primary clinical importance. An adenomyoma is oval in contour where as the leiomyoma is rounded. The margin of the adenomyoma at its interface with the myometrium is often irregular or ill defined, where as leiomyomas are sharply defined. Distortion of endometrium may occur if adenomyosis is extensive. The numerous dilated veins which often accompany a leiomyoma are not associated with adenomyosis. The signal intensity of adenomyosis is low on T2W images and on T1W images they blend with the surrounding myometrium. MRI is helpful in differentiating adenomyosis from leiomyomas.

Leiomyomas: They are the most common uterine tumor. These may be solitary or multiple, and are found in submucosal, intramural, or subserosal sites within the uterine corpus (90%) or cervix (5%). A small number are found in the broad ligament or even detached from the uterus. Leiomyomas often calcify (mostly in post menopausal women), and large tumors may develop hyaline, myxomatous, cystic or hemorrhagic degeneration. Torsion, infection and sarcomatous degeneration are infrequent complications. In patients desirous of preserving fertility, myomectomy is increasingly performed as an alternative to hysterectomy. Ultrasound remains the initial imaging modality of choice MRI is the most accurate imaging technique for the detection and localization of leiomyomas. Tumors as small as 0.5 cm can be accurately seen and the precise location can be determined. On T2 weighted images, leiomyomas appear as sharply marginated homogeneous areas of decreased signal intensity. On T1weighted images, non degenerative leiomyomas display a well circumscribed, rounded appearance with medium signal intensity which is often indistinguishable from adjacent myometrium. Occasionally, calcification causes leiomyomas to appear low in signal intensity on both T1W and T2W scans. Degenerative leiomyomas demonstrate variable signal intensities on MRI imaging. The appearance of leiomyomas after administration of gadolinium is variable. Non degenerative leiomyomas may or may not enhance after contrast, depending on the vascularization, and degenerative lesions demonstrate variable enhancement.

Endometrial polyps: These may be sessile or pedunculated, and are almost always benign. Malignant change is only rarely identified within them. On T2 W images endometrial polyp are suspected when the endometrial clarity is distended by an intermediate signal mass. On T1W images, endometral polyps demonstrate medium signal intensity similar to that of normal endometrium. Endometrial polyps enhance after gadolinium contrast, facilitating their detection.

Endometrial carcinoma: Adenocarcinomas account for 90% to 95% of all endometrial carcinomas. Endometrial carcinoma initially invades the myometrium and the the endo cervix. After trans-serosal spread, direct invasion of the parametrium, bladder, or bowel occurs. Lymphangitic spread to pelvic and para aortic lymph nodes are frequent. Hematogeneous and intraperitoneal spread is rare, with the lungs and peritoneal surfaces of upper


abdomen being the most frequent sites of distant metastasis. Metastasis also may occur to liver, bone and brain. The uterus (if not removed surgically) and vaginal apex is the most common sites of local recurrence, which occurs most often within the first 3 years.

Endometrial carcinoma is staged according to the FIGO staging system, which is now a surgical staging system.

FIGO Staging

I. Carinoma confined to uterine corpus A – Tumour limited to endometriumB – Tumour invasion through <50% myometrial thickness C – Tumour invasion through >50% myometrial thickness

II. Cervical InvasionA – Endocervical glandular involvement onlyB – Cervical stromal invasion

III. Invasion of true pelvis A – Invasion of serosa, adenexa, positive peritoneal cytology B – Vaginal metastases.C – Metastasis to Pelvic or para aortic lymph or inguinal nodes

IV. Extension beyond true pelvisA – Invasion of bladder or bowel mucosa.B – Distant metastases.

The prognosis is related to the nuclear grade, depth of myometrial invasion, stage of tumour and presence of lymph node metastasis. In the presence of deep (>50%) myometrial or cervical stromal invasion, preoperative intracavity radiation therapy or more extensive para-aortic lymph node sampling could be planned. CT has limitations in differentiating between stages I and II and also in consistently determining the depth of myometrial invasion.

On non-enhanced MR images, the signal intensity of small endometrial cancers is often similar to that of normal endometrium. Indirect signs of presence of endometrial cancer include increased thickness or lobulation of the endometrial cavity, or the presence of heterogeneous but lower signal intensity mass on T2W images. After I/V contrast administration endometrial carcinoma demonstrates variable enhancement, which may be less or greater than that of myometrium.

MRI is accurate is staging histologically documented endometrial carcinomas.

In general, endometrial carcinomas enhance later than normal myometrium, hence on early phase dynamic scanning endometrial carcinomas will appear hypointense relative to endometrium. Early tumor enhancement may indicate more aggressive pathology. MRI is more accurate than CT or USG for detecting myometrial invasion. MRI is also sensitive in detecting cervical invasion. The most reliable MRI criterion for myometrial invasion is disruption of the functional zone.

MRI can also be used to evaluate extrauterine spread (Stage III and IV) tumor

Carcinoma of the Cervix: The commonest malignancy of female genital tract in India. Nearly 90% of all cervical carcinomas are squamous cell carcinomas. The prognosis is determined primarily by the tumor stage, histolgic grade, size (transverse diameter), location within the cervix (exocervix versus endocervix), depth of stromal invasion, adjacent tissue extension and presence of lymph node metastasis. Accurate staging is important not only for prognosis but also for the choice of optimal therapy.

Cervical carcinoma spreads primarily via local extension or lymphangitic spread. Tumor may locally invade the vagina, lower uterine segment and parametrium to finally reach the pelvic sidewall. The ureters, bladder and rectum may be invaded as the disease advances. Lymphangitic spread occurs first to the internal and external iliac lymph nodes and later to the common iliac and paraaortic lymph nodes. If the tumor extends to lower vagina, metastasis may occur to inguinal nodes. Hematogenous spread occurs only in advanced disease, most commonly involves the chest.

FIGO Staging for Carcinoma of Cervix

0 – Carcinoma in situI – Carcinoma strictly confined to cervix

I.a.1 – Microscopic invasionI.a.2 – Measurable invasion-depth of invasion from base of epithelium <5mm; horizontal spread <7mm.I.b.1 – Lesion of greater dimension than stage I.a.2 but ≤4 cms.I.b.2 – lesions >4cm

II – Carcinoma extends beyond cervix, but not to pelvic side wall or lower third of vagina.

II.a – No obvious parametrial involvement II.b – Obvious parametrial involvement

III – Carcinoma extends to lower third of vagina or to pelvic side wall

III.a – Lower third of vagina involved, no extension to pelvic side wall.III.b – Extension to pelvic sidewall, all cases with hydronephrosis or nonfunctioning kidney

IV – Carcinoma extends beyond true pelvis or involves bladder or rectal nucosa.

Patients with carcinoma in situ (Stage 0) or micro invasive disease (Stage I.a.1 and I.a.2) are usually treated with simple hysterectomy.

Patients with invasive carcinoma (Stage I.b) or Stage II.a disease are treated with radical hysterectomy and pelvic lymph node dissection. A patient with a large tumor or a barrel shaped cervix may be a candidate for adjacent radiation therapy. Patients with more advanced disease typically are treated with radiation therapy CT imaging has several drawbacks. Identifying parametrial extension by CT is difficult and CT is inaccurate in differentiating stage I.b from II.b disease, and in advanced disease, CT under stages pelvic sidewall involvement.

Neither carcinoma in situ nor stage I.a tumor will be routinely identified on MRI.

On T2W images, cervical carcinoma is seen as an abnormal area of high signal intensity, distinct from the normal lower signal intensity cervical stroma. On T1W images, the cervical mass is isointense with normal cervix, uterus and vagina.

Macroinvasive cervical carcinoma, stage I.b appears on T2W images as intermediate signal mass that may expand the endocervical canal, the outer low signal intensity cervical stroma is preserved, the peri cervical tissue is normal.

A tumor is considered stage II.a, when it extends into the upper two thirds of vagina. On T2W images, there is loss of the low signal intensity from the normal vaginal wall.

Parametrial involvement (Stage II.b) is diagnosed when in


addition to loss of the low signal intensity cervical stroma, there is irregularity of the lateral cervical margin, parametrial mass, or stranding within the parametrial fat. Encasement of uterine vessels is helpful in diagnosing parametrial invasion. A tumor is classified as Stage III.a when it extends to the lower third of vagina, and as Stage III.b when it extends to the pelvic sidewall.

The criterion for stage IV.a disease is tumor involvement of the bladder or bowel wall, which appears on T2W images as low of the normal low signal intensity or the wall of the organ. The use of contrast enhanced imaging is helpful in evaluation of advanced disease, especially when invasion of the bladder or rectum results in fistula formation.

Presence of lymph node metastasis is an important prognostic factor, as it adversely affects prognosis. Lymph nodes larger than 1.5cm are considered abnormal. Lymph nodes between 1-1.5 cm in size, multiple lymph nodes are considered suspicious.

MRI is both an accurate and a cost effective means of staging invasive cervical carcinoma, it is superior to either CT or clinical staging. MRI is also more accurate than CT or clinical staging in identifying stromal invasion, depth of invasion, assessing tumor size and parametrial status. MRI and CT are roughly equivalent in identifying lymph node metastasis. Fat suppressed imaging on MRI however improves the detection of parametrial spread.

Ovary

Ovarian Cysts: Simple serous cysts include follicular cysts, corpus luteal cysts, theca lutein cysts, and paratubal cysts. On MRI examination such cysts are homogenous with signal intensity isointense to urine on all pulse sequences - low signal intensity on T1W images and very high signal intensity on T2W images. Cysts filled with proteinaceous fluid may be high signal intensity on both T1W and T2W images. The cyst wall is thin and smooth. Hemorrhagic cysts are most often corpus luteal cysts. On MRI hemorrhagic cysts are commonly intermediate to high signal intensity on T1W images and lower signal intensity on heavily T2W images, although cysts appearing high signal intensity on both T1W and T2W images may also be seen. The cyst wall should be thin and smooth and may demonstrate intense enhancement after gadolinium. Layering (hematocrit effect) or debris may also be seen. Contrast administration may differentiate adherent clot from mural nodule because clot will not enhance after administration of gadolinium.

Endometriosis: It is the presence of ectopic functioning endometrial cavity. It occurs predominantly in the reproductive age women (mostly between 25 to 30 yrs) and affecting as many as 40% of infertile women. The most common sites of involvement in descending order of frequency include ovaries, uterine ligaments, cul-de-sac and pelvic peritoneum covering the uterus, fallopian tubes, rectosigmoid and bladder. However, endometriosis in distant sites, including vagina, lymph nodes, lung, skeletal tissue and bone has been reported. On CT the appearance of endometrioma is varied, and sometimes lesions may appear solid. USG and CT are neither sensitive nor specific in diagnosis or staging of endometriosis. USG or CT cannot accurately identify small implants or adhesions. MRI has been reported to have a sensitivity of 90 to 92%, a specificity of 91 to 98% and an accuracy of 91 to 96% for diagnosing endometriomas.

On MRI, endometriomas appear most commonly as multiple lesions with signal behavior consistent with hemorrhage of varying age. The most specific MR criteria include multiplicity, angular margins or distorted shape, and high signal intensity on T1W images with shading or low signal intensity on T2W images. Small implants may appear as areas of signal void, or solid contrast-enhancing lesions of intermediate signal on T1W images with punctate foci of high signal intensity. Other less specific features include adhesions (obliteration of fat planes between adjacent organs, low signal bands connecting or surrounding pelvic organs, and angulation of bowel loops) and a thick low signal intensity rim, which may enhance after contrast administration. Endometriomas may be high signal intensity on both T1W and T2W images. Endometriomas are bilateral in one third to one half of patients. T1W fat saturated images increase the sensitivity of MRI for diagnosis of small endometriomas (<1 cm). In larger lesions, presence of a malignant neoplasm arising within the cyst should be excluded, as this complication has been documented in 0.3 to 0.8% of patients with ovarian endometriosis. Complications are rare, but include massive ascites, hemorrhage of spontaneous rupture of an endometrioma. MRI may also have a role in monitoring treatment response in patients with endometriosis. There should be no loss of signal intensity of endometriomas on fat-saturation images. Blood clots or intracystic debris within the endometrioma should not enhance after gadolinium administration where as the presence of enhancing nodules or papillary excrescences raises the possibility of underlying malignancy.

Benign Ovarian Neoplasms

Benign cystic teratomas of ovary (Dermoid cysts): Most commonly diagnosed in women of reproductive age. On CT, the presence of fat (-130 to -90 ho) in an ovarian mass is pathognomonic of a dermoid cyst.

On MRI, examination the key to diagnosing a dermoid cyst is the identification of fat within an adenxal mass. On SE sequences, lipid within the lesion will be isointense to subcutaneous or pelvic fat on all pulse sequences. The presence of chemical shift artifact at interface between fatty and non fatty tissue is a specific, but not sensitive MRI finding for teratoma. A T1 weighted fat-saturation sequence must be obtained to distinguish teratomas from endometriomas. MRI findings of fat fluid levels, gravity dependent layering of floating debris or hairball, palm tree like protrusions, mural nodules and areas of signal void assist in the diagnosis of cystic teratoma.

Serous Cystadenomas: Cystadenomas are the most common benign ovarian neoplasms. They are bilateral in up to 20% of patients. Serous cystadenomas are usually cystic, unilocular, thin-walled lesions with a smooth outer surface. The signal intensity usually follows that of simple fluid but may vary with cyst contents. The presence of mucin or hemorrhage within the lesion may cause hyperintensity on T1W as wall as T2W image. Layering, fluid-fluid of levels and internal septations may be noted. Occasionally, regions of low signal intensity on all pulse sequences (psammomatous calcification) may be identified.

Mucinous cystademomas: These are typically multilocular benign cystic neoplasms occurring as frequently as serous cystadenomas. Unlike serous cystadenomas, they are less


commonly bilateral and tend to be much larger. Pseudomyxoma peritonei is a complication that may result if contents of a mucinous cyst are spilled into peritoneal cavity. MRI appearance may be similar to that of serous cystadenomas. There is a tendency toward greater complexity, with layering, fluid-fluid levels, multiple septations and multilocularity more often noted. The mucinous material within cysts may appears high in signal intensity on T1W images

Fibromas: These are solid benign ovarian neoplasms, usually seen in peri and post menopausal women. They are most commonly 5-10 cm in diameter. Bilaterality is seen in up to 10% of cases. On MRI, fibromas are usually well defined solid tumors, with intermediate signal intensity on T1W images and low signal intensity on T2W images. Irregular foci of hyperintensity may be seen on T2W images (areas of hyalinization and myxomatous change). The constellation of findings seen in Meig’s syndrome (ovarian fibroma, hydrothorax and ascites) occur in 1% of patients with ovarian fibromas.

Ovarian Carcinoma

It is predominantly a disease of peri and postmenopausal women. Ovarian carcinoma usually spreads by direct shedding into the peritoneal cavity, local extension or lymphatic dissemination. Hematogeneous spread is rare. The most common pathway for spread is through peritoneal space. Malignant cells are carried by peritoneal fluid from the pelvis and cul-de-sac inferiorly to the diaphragm superiorly. Peritoneal fluid extends mainly along the right paracolic gutter to the liver surface and right hemidiaphragm. Malignant cells may pass through diaphragmatic lymphatics to implant on the pleura producing a malignant pleural effusion. The omentum is involved in nearly 100% of patients dying of ovarian carcinoma. The ovarian lymphatics drain primarily to para-aortic nodes and secondarily to pelvic and inguinal lymph nodes. Hematogenous spread is less common and may occur as a late manifestation. Distant organs at risk of metastasis in decreasing order of frequency are liver, lung, pleura, kidney, bone, adrenal gland, bladder and spleen.

FIGO Staging System

I. Limited to ovariesA. One ovary/no tumor on external surfaceB. Both ovaries/no tumor on external surfaceC. Malignant ascites/positive peritoneal washings/tumor on surface of ovaries

II. Pelvic extension.A. Uterus or fallopian tube involvedB. Extension to other pelvic tissuesC. Malignant ascites/positive peritoneal washings

III. Introperitoneal metastases outside of pelvis, including small bowel and omentum, positive retroperitoneal or inguinal lymphnodes

A. Microscopic seeding.B. Implants < 2 cm.C. Implants > 2 cm and/or positive lymphnodes

IV. Distant metastases, including positive pleural fluid, parenchymal liver metastases.Aggressive debulking surgery, followed by combination chemotherapy is the gold standard of treatment. The prognosis is dependent on the stage of tumor at presentation, volume of tumor remaining after debulking surgery, histological grade, and the age of patient.

MRI Characterization of Carcinoma Ovary

The role of imaging lies in lesion detection, characterization, staging and follow up. In the detection of adenexal lesions, sensitivity of MRI is comparable to USG and CT. The ability of MRI to characterize adenexal tumors as benign or malignant with high specificity has also been shown. In the characterization of adenexal masses, MRI is more accurate than either USG or CT. MRI is particularly useful for differentiating the uterine versus adenexal origin ovarian masses. On MRI, ovarian carcinoma usually appears as a large (>4cm), heterogenous, solid and cystic lesion which is not uncommonly bilateral. Well differentiated tumors of low malignant potential appear primarily cystic, with intracystic vegetations present, while undifferentiated tumours have large amounts of solid tissue, necrosis and hemorrhage. Solid components of ovarian carcinoma usually appear as low to intermediate signal intensity on T1W images and high signal intensity on T2W images, however signal may vary depending on whether hemorrhage or necrosis is present. The cystic component of ovarian carcinoma may also have a variable appearance on MRI, depending on cyst contents. Cystic ovarian carcinomas containing proteinaceous or hemorrhagic material may manifest high signal intensity on both T1W and images. Cystic carcinomas may demonstrate thick walls or septa (<3mm), and contain vegetations or regions of soft tissue nodularity. The findings are best demonstrated on either T2W or Gadolinium enhanced T1W images.

Use of Gadolinium expedites lesion characterization by facilitating assessment of intratumoral architecture. Gadolinium is useful in determining wall thickness, presence and thickness of septations, identification of vegetations or soft tissue nodules, and depiction of tumor necrosis. Gd enhanced MRI is more accurate than noncontrast MRI and endovaginal sonography in differentiating benign from malignant lesions.

MRI is as accurate as CT in ovarian cancer staging. Prediction of tumor resectability is excellent for both MRI and CT. Criteria for tumor non resectability include:a) Metastases >2 cm at root of mesentry, gastrosplenic ligament,

omentum of the lesser sac, porta hepatis, intersegmental tissue of the liver, diaphragn or dome of liver

b) Enlarged (short axis >1cm) lymph nodes at or superior to the oveliac axis

c) Presence of presacral extraperitoneal disease

MRI may be superior to CT in assessment of pelvic involvement by ovarian carcinoma. The presence of ureteral obstruction with hydronephrosis as well as disease extension to the pelvic side wall or retroperitoneum may be seen on MRI.

Outside the pelvis, MRI maybe useful in detecting ascites, peritoneal implants, omental cake and mesenteric disease. Implants demonstrate low signal intensity on TW images and enhance post gadolinium. When involved by metastasis, omentum is enlarged and may be seen as intermediate signal intensity crescent-shaped mass surrounded by ascites. It enhances diffusely after Gadolinium administration MRI detection rate for pelvic and retroperitoneal lymphadenopathy is very good and equals that of CT. MRI is slightly better than CT in assessing colonic and uterine invasion as well.


A Time to Shape Up

Dinesh Bhargava

Body Contouring (Aesthetic reshaping)With the advent of the new technology and the understanding of the changes that occur in human form, there is a variety of surgical procedure designed to change the body form, safely, effectively and often permanently.

The success and effectiveness of these body contouring procedures is influenced by your age, size and nature of your skin in the related treated area. People benefit in terms of their ability to enjoy wearing bathing suits and form-fitting clothes and in general exhibit more self confidence.

Augmentation Mammaplasty (A Patient’s Choice)Breast enlargement surgery also called breast augmentation is designed to increase the size and volume of an underdeveloped breast and to add volume in a breast that has changed after child birth and breast feeding.

The procedure requires an introduction of a prosthesis (silicone of saline filled) behind the breast to effectively changes the breast size and shape.

Breast Reduction (A Patient’s Need)The limitations of large breast often are functional, in the young they can have psychological problems while later on in life they can lead to physical changes in posture and ultimately to bony changes. The procedure is designed to reduce the size of the breast attempting to preserve its functions and aesthetics. Mastopexy (Breast lift)Breast lift or mastopexy is designed to restore a youthful appearance of the breast in women who have developed changes in the breast after child birth, lactation and subsequent involution of the breast. This could also be due to significant weight loss. Even though the incisions are often the same as reduction mammoplasty, there is minimal removal of breast tissue (sometimes volume is added) to elevate a drooping breast.

Correction of Gynecomastia (Removal of breast tissue in men)The development of breasts or breast like appearance in men in termed gynecomastia. The correction

is done using ultrasonic assisted liposuction and excision to contour the chest.

Liposuction Ultrasonic (Body contouring by fat removal)This is the most frequently done aesthetic surgery procedure, which is effective and safe in removing unwanted fat and in contouring the abdomen, the flanks, the chest, the arms and the facial region with or without other surgical procedures. Over the years, several variations of the conventional liposuction have been developed including use of Ultra sonic energy, Laser assisted and power devices. The technique chosen is as per specific needs.

Abdominoplasty (Tummy Tuck)Abdominoplasty, commonly Know as Tummy Tuck is designed to correct the loose abdominal skin and muscles that occurs after pregnancies. This may also be after severe weight loss. In the present day context it is not the abdomen that is corrected at the time of abdominoplasty but an over all improvement of the torso is planned often with the combination of liposuction and lateral tension variation of the abdominoplasty

Breast Reconstruction after Mastectomy (A Patient’s Right)Recreating a breast after breast removal after surgery discussion of breast reconstruction after breast surgery for cancer should be part of the deliberation when considering treatment of cancer. While it does not change the course of the disease ‘breast cancer’, it does markedly improve the quality of life of those who are afflicted with this form of cancer.An opportunity to make a person ‘whole’ again after the devastating surgery is very rewarding both to the aesthetic surgeon and the patient.

Rehabilitation after severe weight lossCorrection sagging skin after severe weight loss with the health conscious society obesity is being shunned and people are loosing weight either on their own or with the support of their physician or dietitians. In any case, the excessive skin that remains often is a physical hindrance or psychological reminder of what used to be. Correction of these concerns is progressively being done to facilitate the rehabilitation of these persons.

Dinesh Bhargava

HOD, Dept. of Aesthetic &

Plastic Surgery

Pushpanjali Crosslay Hospital

Vaishali, Ghaziabad (NCR)


Initial Management of Polytrauma Patient

Sandeep Jain

IntroductionTrauma is a leading cause of death and disability. With increasing vehicular population and urbanization it is becoming more prevalent. Management of a multiple injured or a polytrauma patient can challenge even an astute clinician. In India, Emergency Medical Services are still in a primitive state. Most of the times the trauma victim does not reach the hospital in time and in many of the hospitals there is a shortage of trained manpower and resources to handle them. Therefore, it is imperative for all medical and paramedical personnel to gain the knowledge of basic trauma management which can be provided with the available resources, so that the patient receives the immediate care before being shifted to a trauma centre.

EpidemiologyTrauma mostly affects the young productive population in the age group of 15 - 44 years. It not only kills an individual but paralyses the whole family. It is estimated that in India there is one road traffic accident every minute and every three minutes there is a death due to these. For every one death there are twenty disabled and fifty injured persons left in the society. In the year 2008, in India 3.42 lakh deaths were reported due to accidents, 93% of which were due to unnatural causes like road traffic accidents, falls from height, assaults, railway traffic injuries, burns, drowning etc. Road traffic accidents were responsible for 37.1% of these 1. Presently Road Traffic Accident (RTA) is the ninth most common cause of death amongst all diseases in world but as per WHO projections, by the year 2020 it will be the third in this list2.

Deaths from trauma have a trimodal distribution3. This refers to occurrence of death following trauma as a function of time. Accordingly these are classified as:Immediate deaths: these occur within seconds to minutes after injury and are due to heart or major vascular rupture, brain stem injury or massive head injury.Early deaths: these are the deaths which occur after few minutes to hours after injury. Usual causes are

airway obstruction, tension pneumothorax, closed

head injury or hypovolemic shock.

Late deaths: these are deaths occurring days after

injury, in the intensive care units and are due to

septicemia, coagulopathy and multiorgan failure.

Immediate deaths are non salvageable and only

preventive measures like following traffic rules, using

helmets etc. can save them. Early deaths are the

preventable deaths where appropriate diagnosis and

treatment can make a difference between survival

and mortality. Late deaths are a consequence of

injury severity and inappropriate initial care.

Essential trauma care is all about preventing early

and late deaths. Dr Adams R Cowley of Shock

Trauma Centre at Baltimore, Maryland, USA found

that the survival of the trauma patient was time

dependent. The longer the time taken for providing

appropriate care, the lower was the survival rate.

He called this the ”Golden Hour”, emphasizing

the need for early treatment of these patients. The

Golden hour starts from the time of injury and not

when the first medical personnel have arrived4.

Initial Assessment and Management of Patient

A good pre hospital care is absolutely necessary

for better survival. There is a need to shift the

patient early to an appropriate trauma centre and

continuous care should be given en route. This

policy is called” Load and Go” or “Scoop and Run”,

which is being practiced in India. Another concept

of “Stay and Play” is in vogue in some countries in

Europe which implies that the patient is treated and

stabilized at site of accident before the transport.

Before approaching the patient at site it is essential

that the pre hospital team ensures that the place is

safe for them to load the patient and they have their

universal precautions in place. Always approach the

patient from his front side and address him to elicit

a response. A patient who is able to talk coherently

- has an intact airway, sufficient oxygenation and

adequate perfusion of brain tissue. The EMS

team should also communicate with the receiving

hospital so that the trauma team is ready to receive

the patient.

The initial management is divided into two phases;

primary survey and secondary survey. Primary

survey deals with the management of immediate

life threatening injuries while secondary survey is

comprehensive management of all injuries.

Sandeep Jain

Consultant Trauma Surgeon

ATLS and ITLS instructor

Pushpanjali Crosslay Hospital

Vaishali, Ghaziabad (NCR)


Primary Survey:This can be summarized as first five letters of English alphabets (ABCDE) - Airway with cervical spine control, Breathing, Circulation, Disability and Exposure & Environment control.1. Airway with Cervical Spine Control: Airway is assessed by talking to the patient. If he is able to talk coherently, his airway is clear. If he is unable to speak, is unconscious or is producing additional sounds like stridor, gurgles etc, his airway is threatened.The airway is cleared by opening the mouth with chin lift or jaw thrust maneuver. Fig.1 (Head tilt as taught in Basic Life Support courses is contraindicated in trauma).

Fig.1: Jaw thrust maneuver

After opening the mouth remove any foreign body or secretions by

finger sweep or suctioning. Various airway adjuncts can also be used

to maintain a patent airway5.

A. Oral or nasopharyngeal airway: Oral airway is used in unconscious

patients with no gag reflex. Nasopharyngeal airway is used in

patients who have a persistent gag reflex or where it is difficult

to introduce oral airway, as when the patient clenches his mouth.

Contraindication of nasopharyngeal airway includes fracture base

of skull - bilateral periorbital edema (panda sign), ecchymosis at

mastoid (battle’s sign), rhinorrhea and otorrhea.

B. Laryngeal Mask Airway (LMA): This can be used in conditions of

difficult or failed intubation. This can also be put in the field by

paramedics without the need for laryngoscope. Since it does not

prevent against aspiration, it is not a preferred technique.

C. Others could be esophageal tracheal combitube or esophageal

obturator airways.

D. A definitive airway is endotracheal intubation. A definitive airway

is defined as a tube in the trachea with cuff inflated, tube attached

to oxygen enriched ventilation, and the airway secured in place4.

It is the gold standard for airway maintenance. However, it is

difficult in trauma situations as the head always remains in neutral

position.

E. In case of failed intubation surgical airways can be created at

cricothyroid membrane by either needle cricothyrotomy or

surgical cricothyrotomy. Emergency tracheostomy is more

difficult, requires greater expertise and is associated with greater

operative risk than cricothyrotomy. Hence it is now reserved for

intensive care settings.

Cervical spine is always assumed to be injured until proven

otherwise in all trauma patients.

It is imperative that a member of the trauma team immobilize

the cervical spine by holding it with hands, called “in line manual

stabilization” till airway has been secured. It is then augmented with the application of a semi rigid collar.

2. Breathing: Injuries of respiratory apparatus (rib cage and pleural cavity with its contents) are an important cause of preventable early deaths. These are grouped as lethal six (airway obstruction, tension pneumothorax, massive hemothorax, open pneumothorax, cardiac tamponade and flail chest) and hidden six (blunt cardiac injury, lung contusion, esophageal perforation, tracheobronchial disruption, diaphragmatic tear and blunt aortic injuries).A. Tension pneumothorax: It is a condition which results from

injury to lung parenchyma, tracheobronchial tree or chest wall. Collection of air under tension in pleural cavity leading to severe respiratory and hemodynamic compromise results in rapid mortality. As air in pleural cavity expands rapidly, many a

times there is not enough time to perform radiography; hence in

effect diagnosis is mostly clinical. Patients usually presents with

breathing difficulty with unstable hemodynamic parameters.

Examination will reveal distended neck veins, reduced or absent

breath sounds on affected side with hyper resonant note on

percussion.

Treatment starts with early diagnosis and performing needle

decompression (needle thoracentesis). This is performed on the

side of tension pneumothorax with a 14G venflon or angiocatheter

inserted in 2nd intercostal space in midclavicular line. Most of

the times it is difficult to exactly count the space, therefore a

rough method is to palpate the midpoint of clavicle and the first

palpable intercostal space below is the 2nd space. Alternatively

draw an imaginary line joining the midpoint of clavicle and the

ipsilateral nipple and midpoint of this line is 2nd space. Needle

thoracentesis is a temporary method described mostly in the pre

hospital care setting for purchasing time to shift the patient to the

hospital. In emergency room the definitive treatment is insertion

of chest tube in midaxillary line in 4th or 5th intercostal space. If

there is a delay in getting the instruments or expertise for tube

decompression, needle decompression is still life saving in rapidly

deteriorating patient.

B. Massive hemothorax: Collection of more than 1.5 litres of blood

in pleural cavity is termed as massive hemothorax although each

hemithorax can contain up to 3 litres4. The bleeding is mostly

from intercostal or internal mammary vessels but could be from

major vascular structures as well. The sign and symptoms are same

like those of tension pneumothorax except that the percussion

note changes to dull and neck veins can be flat secondary to

hypovolemia. Since trauma chest X rays are supine films, classical

crescent sign of pleural effusion will not be seen; rather a diffuse

opacification of involved hemithorax will be the finding on X ray.

Treatment is tube decompression of pleural cavity with volume

replacement. If initial collection is more than one litre or there

is a continuous drainage of more than 200ml/hr for ≥ 2 hours,

there is a high possibility of the need for thoracotomy. Therefore

an early referral to a trauma or thoracic surgeon should be

considered.


C. Open pneumothorax (sucking chest wound): This is a condition

where there is an open wound on the chest wall communicating

with the atmosphere. When the defect in the chest wall is more

than two third the diameter of the trachea, air enters the pleural

cavity preferentially through this defect, leading to serious

hemodynamic and respiratory compromise.3

The treatment is closure of the defect with tube decompression.

However in prehospital setting or in case of delay in chest tube

decompression, a temporary closure of the defect by putting a

barrier such as butter paper, plastic dressing or rubber glove and

sealing it only on three sides4 will purchase some time. During

the inhalation the barrier is sucked in due to creation of the

negative intrathoracic pressure preventing any further ingress of

air while during exhalation the barrier is lifted up and the open

side allows the egress of the collected air.

D. Cardiac tamponade: collection of blood in the pericardial

cavity prevents adequate cardiac function leading to severe

hemodynamic compromise. This is suspected in patients with

frontal collision and sternal or anterior chest wall injuries. Sign

and symptoms are usually same as tension pneumothorax except

that the air entry is equal. Classical Beck’s Triad (raised jugular

venous pressure, muffled heart sounds and hypotension) is found

in only 33% of patients5. Pulsus paradoxus (fall in systolic blood

pressure more than 10mm Hg during inspiration) is difficult to

ascertain in trauma patient. Kussmaul’s sign (raised JVP during

inspiration in spontaneously breathing patient) is a hard sign but

again is difficult to interpret in polytrauma scenario. (Table 1)

Treatment is pericardial decompression by sternotomy or

thoracotomy. Diagnosis is usually confirmed by FAST (focused

abdominal sonography for trauma). Needle pericardiocentesis is

a temporizing measure to purchase time for shifting of patient for

surgery.

E. Flail chest: It is defined as fracture of two or more ribs at two

or more places3. The flail segment produces paradoxical motion

and hampers respiratory physiology. The major threat to life is

not due to fractures or the paradoxical motion but due to the

underlying tension pneumothorax /hemothorax and associated

lung contusions. Hence a diagnosis of flail chest should alert the

clinician to the need for finding the underlying injury.

The treatment of flail chest is oxygen supplementation with

good analgesia and chest physiotherapy; associated tension

pneumothorax or hemothorax having been treated as discussed

above. In case of failure to maintain oxygenation, intubation and

positive pressure ventilation is the treatment of choice. In the

modern era there is no place for any strapping or fixation of the

fractures. The only indication of rib fracture fixation is concurrent

thoracotomy for other causes.

3. Circulation: The aim of assessment of the circulatory volume in

a polytrauma patient is to diagnose and manage shock early before

decompensation. The shock can be hypovolemic (due to blood

loss), neurogenic (spinal cord injury) or cardiac compressive (tension

pneumothorax and cardiac tamponade).

In polytrauma patients shock is considered to be hypovolemic

until proven otherwise.

The treatment is aimed at restoring organ and tissue perfusion. The

classical signs of hypovolemic shock appear in only class III (Table 2).

Therefore any trauma patient with tachycardia should be considered

Examination findings

Tension pneumothorax Massive hemothorax Cardiac tamponade

Inspection • Respiratory distress• Tachypnea • Distended neck veins• Unequal chest wall movements• Contusion, abrasion or laceration

on chest wall

• Respiratory distress• Tachypnea• Neck veins may be flat • Unequal chest wall

movements• Contusion, abrasion or

laceration on chest wall

• Respiratory distress• Tachypnea• Distended neck veins • Equal chest wall movements• Contusion, abrasion or laceration on anterior chest wall

Palpation • Tachycardia with hypotension• Tracheal shift to opposite side• Subcutaneous emphysema• Palpable rib fractures

• Tachycardia with hypotension • Tracheal shift to opposite side• Subcutaneous emphysema• (hemopneumothorax)• Palpable rib fractures

• Tachycardia with hypotension• Trachea central• No subcutaneous emphysema• Palpable sternal or anterior rib fractures

Auscultation Reduced or absent air entry on affected side

Reduced or absent air entry on affected side

Air entry will be equal

Percussion Hyperresonant note on affected side Dull note on affected side Both sides normal resonant note

Table 1: Comparison of clinical features of tension pneumothorax, massive hemothorax and cardiac tamponade


to be having some bleeding somewhere and active search for it should

be performed till excluded. The management of shock encompasses

control of bleeding and restoration of intravascular volume. The

sources of blood loss can be overt (from major external wounds or

vessels) or could be covert (intrathoracic, intraabdominal, long bones,

pelvis and retroperitoneum).

Table 2: Classification of Hypovolemic Shock3

Class I Class II Class III Class IV

Blood loss (% of total blood volume)

< 15% 15-30% 30-40% >40%

Pulse (per min)

< 100 100-120 120-140 >140

SBP Normal Normal Low Low

Pulse pressure

N / High Low Low Low

RR (per min)

14-20 20-30 30-40 >40

Urine Output (ml/hr)

>30 15-30 5-15 Negligible

Mental status

Anxious Irritable Confused Lethargic

Fluids Crysta-lloids

Crysta-lloids

Crysta-lloids+ blood

Crysta-lloids+ blood

External bleeding is controlled with compression dressings; long

bone fractures are stabilized with available splints. Unstable pelvis

is diagnosed clinically by ability to compress or retract pelvis at

iliac blades. This maneuver should be done only once and if found

positive, a pelvic binder should be applied for stabilization. X rays of

chest and pelvis along with FAST will help in diagnosing the cause of

concealed hemorrhage.

Two wide bore cannulae (preferably 14G) should be inserted to start

crystalloid infusion. A bolus dose of 1-2 litres of Ringer’s Lactate

in adults and 20ml/Kg in pediatric population is initially given3.

Depending upon the response to this bolus dose the patients may be

categorized into:

a) Responders: these respond to the bolus dose and maintain

thereafter when the infusion rate is slowed down. These patients

should be admitted in intensive care, monitored and further

investigations undertaken.

b) Transient responders: these respond initially but when the

infusion rate is slowed, start to deteriorate. These have a high

chance of undergoing a surgical intervention and the surgical

team along with blood bank should be alerted.

c) Non Responders: These patients show absent or minimal

response to bolus dose. They are to be shifted immediately to

OT for control of bleeding, with ongoing resuscitation. In this

group of patients bedside CXR / Pelvis/ FAST only need to be

done during resuscitation.

4. Disability: Assess level of consciousness with the help of Glasgow

Coma Scale (GCS) score (Table 3)

Table 3: Glasgow Coma Scale

Score Eye opening Verbal response Motor response

1 None None None

2 To pain Incomprehensible sounds

Extensor (decerebration)

3 To command Inappropriate words Abnormal Flexion (decortication)

4 Spontaneous Confused Flexor Withdrawal

5 Oriented Localizes pain

6 Obeys command

In prehospital care a simpler scale (AVPU) can also be used for assessment of level of consciousness A – Alert V – Responding to verbal commands P – Responding to painful stimulus U – Unresponsive

In addition the size and light reaction of both the pupils need to be assessed. Inequality of pupils or non reactivity to light is indicative of an underlying brain injury. As opposed to hypotension and tachycardia, in closed head injuries with raised intracranial pressure hypertension and bradycardia is found (Cushing’s reflex). Head injuries can be classified into primary and secondary brain injury. Primary injury occurs as a result of impact at the time of accident while secondary injuries are due to the factors involved after the accident. Clinically head injury is divided into minor (GCS 12-15), moderate (GCS 9-12) and severe (GCS 3-8).

In head injuries the initial management is directed towards maintaining the Cerebral Perfusion Pressure (CPP) which is defined as the difference between the Mean Arterial Pressure (MAP) and Intracranial Pressure (ICP).

CPP= MAP – ICP.Normal ICP is 10mm Hg and pressure more than 20mmHg is associated with poor outcomes3.Therefore in head injuries when the intracranial pressure rises due to any mass lesion or diffuse cerebral edema, the mean arterial pressure has to be correspondingly raised to maintain CPP. Thus even in the presence of head injury the primary management is to keep the systolic blood pressure above 110mm Hg so as to maintain CPP above 60mm Hg4. The aim in the initial management is to prevent secondary brain injury which could be due to hypoxia and hypovolemia.

Hypotension and tachycardia in patients with suspected head injury should alert the clinician towards ongoing concealed hemorrhage elsewhere.


References1. Accidental Deaths and Suicides in India, 2008, National

Crime Records Bureau2. Global Burden of Disease, 2004, World Health

Organization3. Advanced Trauma life Support for Doctors, 8th ed.

2008, American College of Surgeons4. Basic Trauma Life Support, 5th ed. 2004, JE Campbell,

American College of Emergency Physicians5. The Trauma Manual, 2nd ed.2002, AB Peitzman et al.

Lippincott Williams & Wilkins

5. Exposure and environmental control: This is an important facet of trauma management which if neglected could adversely affect the outcome. All serious trauma patients should be completely exposed to prevent incidence of missed injuries. After evaluation the patients also need to be covered and efforts are to be initiated to prevent hypothermia. In patients with hypovolemic shock, acidosis due to anaerobic metabolism, combined with dilutional coagulopathy in the presence of hypothermia sets up a vicious cycle, leading to high mortality. This triad of hypothermia, acidosis and coagulopathy is aptly called the “lethal triad of death”. Hypothermia inactivates the clotting enzymes in the coagulation cascade and alters the platelet function. This thrombasthenia makes bleeding control difficult, irrespective of infusion of any amount of blood and its products. Thus all care should be taken in the initial management of polytrauma patient to prevent setting of hypothermia.

Adjuncts to primary surveyDuring this phase investigations which can be done are bedside X rays of Chest and pelvis and Focused abdominal sonography for trauma (FAST). The focus in sonography for trauma is to find significant free fluid in abdomen mandating the need for early laparotomy, irrespective of the organ injured. This is a quick bedside examination which is easily performed by trauma surgeons and emergency physicians. In addition blood samples can be drawn for baseline hemoglobin, hematocrit, grouping and cross matching.

A nasogastric tube should also be put to decompress gastric contents (contraindicated in suspected basal skull fractures). Foley’s catheterization in the absence of signs of urethral rupture will help in monitoring of urine output during resuscitation.

CT scan of brain and cervical spine should only be performed when the patient is stabilized. No unstable patient should be shifted to CT room where resuscitation is often compromised. In fact CT room has been called as “graveyard of trauma patients”.

Secondary surveySecondary survey is a head to toe examination for presence of other non life threatening injuries. Make note of abrasions, contusions, deformity, swellings, lacerations or any other sign of injury. Secondary survey should be done only after the patient has been stabilized. Many a times it is completed in the post operative period after control of bleeding. Alongside take the patient history, components of which can be remembered as a mnemonic (AMPLE)

A – AllergiesM - Current medicationsP - Past illnesses / pregnancyL – Last meal timeE - Events leading to accident

Transport of the patientWhen the patient needs to be transported the following should be rechecked:a. Airway is securedb. Breathing is not compromisedc. Circulation is good enough to maintain cerebral perfusiond. Patient is put on spine board after “log roll” and cervical collar

application.e. Any impaled object in the body is not removed

Trauma Training in IndiaVarious trauma training courses are available in India at this moment. Some of them are listed below:1. Fellowship of National Board of Examinations (FNB): This is a

post doctoral two year fellowship program for post graduates in Surgery, Orthopedics, Neurosurgery and Anesthesia. (www.natboard.edu.in)

2. Advanced Trauma Life Support (ATLS): This is a three day course of American College of Surgeons for MBBS /BDS doctors (www.atls.in)

3. International Trauma Life Support (ITLS): This is a two day course of American College of Emergency Physicians, concentrating on pre-hospital trauma care. This is meant for doctors, nurses and paramedics. (www.itrauma.org)

4. National Trauma Management Course (NTMC): This is a two day course of Indian Academy of Traumatology. ( www.indiatrauma.org).

5. Comprehensive Trauma Life Support (CTLS): This is a two day course of Trauma Care International. (www.ctlsindia.org)

SummarySurvival of a trauma victim is time dependent. Availability of appropriate healthcare facility can reduce the rate of preventable deaths. Maintaining ABCDE of trauma does not involve great expenditure but can be taken care of with available resources and adequate training. Trauma care is a team work and therefore a lot of responsibility lies with doctors to train and lead their team of healthcare workers.

invites case studies, original, and review articles on

different specialtiesPlease sumit your contributions by email

[email protected], [email protected]

orby post at the address given below

Pushpanjali Medical Publications Pvt. Ltd. A-14, Pushpanjali, Vikas Marg Extn.,

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Fax no. 011-22372851


Charu DuaHead -Dept. of DieteticsPushpanjali Crosslay HospitalVaishali, Ghaziabad (NCR)

Trans Fats – The Truth

Charu Dua

Products containing trans fats are being

introduced in the Indian market, and being

advertised as cholesterol free. The myth about

margarine being better than butter existed in

the market worldwide till the US Food and Drug

Administration made it a policy that food labels

should contain the following information:

1. Energy

2. Carbohydrates

3. Fiber

4. Fat

5. Fatty acids

• Saturated Fats

• Unsaturated Fats

• Trans Fats

6. Cholesterol

7. Protein

The fact is that trans fats are neither required

nor beneficial for health.

Sources

Trans fatty acids (TFA) come from two major

sources.

1. Probably 10 percent of the intake of trans

fatty acids are found naturally in products

from ruminant (cud-chewing) animals. The

bacteria in the stomach of these animals

such as cows and sheep, breaks down and

in the process mix hydrogen with some of

the natural fats.

2. The largest amount of trans fat consumed

today is created by the processed food

industry. These contribute about 90 percent

of the trans fatty acids in the average western

diet.

What is the need of trans fatty acid in processed

food?

Trans fats were invented as scientists began

to “hydrogenate” liquid oils so that they could

withstand the food production process since

partial hydrogenation reduces rancidity and

consequently increases product shelf life.

As baking requires semi solid fats, partially

hydrogenated oils are effectively used to replace

the animal fats traditionally used by bakers (such

as butter and lard). There are also some readily

available alternative to semi solid fats such as

tropical oils like palm oil. Trans fatty acids are

found in many commercially packaged foods,

commercially fried food such as French fries

from fast food chains, other packaged snacks

such as microwave popcorns, as well as in

vegetable shortening and hard stick margarine.

Chemistry

Fatty acids are characterized as saturated or

unsaturated based on the number of hydrogen

atoms in the acid. If the molecule contains

the maximum possible number of hydrogen

atoms then it is saturated; otherwise, it is

unsaturated.

Trans fatty acids contain at least one double

bond in the trans configuration. The carbon/

carbon double bonds of fatty acids exist in

either the cis or trans configuration. When

the two hydrogen atoms are on opposite sides

of double bond, the configuration is termed

trans, when the two hydrogen atoms are on the

same side of the double bond, the configuration

is termed as cis. Lack of rotational mobility

precludes interconversion of configurations

under normal circumstances. The bond angle

is larger for a trans than a cis double bond.

Therefore, the presence of a trans, relative to a

cis, double bond results in acyl chains that can

pack together more tightly.

To further clarify this, oleic acid and elaidic acid

both are unsaturated fatty acid with the chemical

formula C18H34O2. They both have double bond

9 carbon atoms from the end of the molecule. It

is the conformation of this bond that sets them

apart. The conformation has implications for the

physical-chemical properties of the molecule.

The trans configuration is straighter, while the

cis configuration is noticeably kinked as can

be seen from the following three-dimensional

representation. (Figure 1)

The trans fatty acid elaidic acid has different

chemical and physical properties due to its

slightly different bond configuration. Notably, it

has a much higher melting point, 46.5 °C rather

than oleic acid’s 13.5 °C.

Effects of trans fatty Acids

Just about 2.6 gm a day of trans fat (half a much

as is contained in a packet of French fries)


Elaidic acid

Elaidic acid is a trans unsaturated fatty acid often found in hydrogenated vegetable oils

Oleic acidOleic acid is a cis unsaturated fatty acid that comprises55-80% of olive oil.

These fatty acids are geometric isomers (chemically identical except for the arrangement of the double bond).

Figure 1: Image courtesy: http://en.wikipedia.org/wiki/Elaidic_acid, http://en.wikipedia.org/wiki/Oleic_acid

raises the risk for heart disease. Trans fatty acid manifest their deleterious effects through the following mechanisms:1. By damaging the normal membrane of cells, therefore

strongly affecting the cell’s ability to take in appropriate nutrition. Membrane damage also effects electrolyte balance in the body, increasing irritability in that cell and in organs such as the heart - thereby increasing the risk for sudden cardiac death.

2. By having a similar ability to raise LDL cholesterol as saturated fat.

3. By reducing HDL cholesterol, and increasing the risk for cardiovascular disease.

4. By elevate lipoprotein (a) levels.

The data on trans fatty acid intake and plasma lipid levels are relatively consistent; trans fatty acids or hydrogenated fat result in higher plasma cholesterol levels than native oil and lower plasma cholesterol levels than saturated fats. Effects on triglyceride levels are highly variable. These results have persisted despite the marked difference among study designs, levels of Trans fatty acid consumed by study subjects, and actual sources of trans fatty acids. Not withstanding these data, a pivot study published in 1990 refocused attention on trans fatty acids from total cholesterol levels to effects on specific lipoprotein particles. When a relatively high level of a transfatty acid, 11% of energy as elaidic acid (18:1 trans9), was substituted for a cis fatty acid, oleic acid (18:1 cis9), or a saturated fatty acid, stearic acid (18:0), total and low-density lipoprotein (LDL) cholesterol levels increased whereas high density lipoprotein (HDL) levels were comparable when the subjects consumed the oleic or stearic acid-enriched diets. HDL levels were lower when they consumed the elaidic acid–enriched diet. These changes resulted in a less favorable total cholesterol/ HDL cholesterol ratio. Using a similar study design but a lower level of trans fatty acid, 7.7% of energy, this basic observation was made again .Subsequent confirmation of the independent effect of trans fatty acid on HDL cholesterol levels have been inconsistent. The majority of studies have reported that trans fatty acid intake increases Lp(a) levels.

Another trial indicating similar results is a meta-analysis of 12 randomized, controlled trials of trans fatty acid consumption published in the New England Journal of Medicine (354:1601-1613, 2006) (Figure 2). The data was derived from 524 subjects in 39 separate study groups or study periods with the use of previously described methods and established effects of saturated and cis unsaturated fats on serum lipid levels. As compared with the consumption of an equal number of calories from saturated or cis unsaturated fats, the consumption of trans fatty acids was found to raise levels of low-density lipoprotein (LDL) cholesterol, reduce levels of high-density lipoprotein (HDL) cholesterol, and increase the ratio of total cholesterol to HDL cholesterol, all of which are powerful predictors of the risk of CHD.

Trans fats were also found to increase the blood levels of triglycerides as compared with the intake of other fats, increase levels of Lp(a) lipoprotein, and reduce the particle size of LDL cholesterol, each of which may further raise the risk of CHD. Thus, trans fatty acids have markedly adverse effects on serum lipids. Although these effects would be expected to increase the risk of CHD, the relation between the intake of trans fats and the incidence of CHD reported in prospective studies has been greater than that predicted by changes in serum lipid levels alone, suggesting that trans fatty acids may also influence other risk factors for CHD.

Trans Fatty Acid Consumption in Asian Indians (Recommended Intake of Trans Fatty Acid is 5 g, ie, <1% of energy of fat)

Group Mean Males Females

Children 1.16% (n=1238)

1.10% (n=607)

1.23%(n=631)

Adults 0.46%(n=509)

0.36%(n=255)

0.60%(n=254)

Misra et al. 2006 (Unpublished Observations)


Figure 2: Change in total HDL and levels of LDL and HDL levels on trans fat replacement (Mozaffarian D, et al. N Engl J Med 2006)

Typical trans fatty acid content of foods produced or prepared with partially hydrogenated oils

Type of Food Trans Fatty Acid Content

g/Typical Serving g/100g % of Total Fatty Acids

Fast Food

French Fries 4.7 – 6.1 4.2 – 5.8 28 – 36

Breaded Fish Burger 5.6 3.4 28

Breaded Chicken Nuggets 5.0 4.9 25

French Fries Frozen 2.8 2.5 30

Pizza 1.1 0.5 9

Tortilla (Corn Chips) 1.6 5.8 22

Popcorn microwave 1.2 3.0 11

Bakery Products

Cakes 1.7 2.7

Cookies/ Biscuits 1.8 5.9

Muffins 0.7 1.3

Others

Garnola Bars 1.0 3.7 18

Vegetable shortening Margarine 2.7 19.2 19

Hard (Stick) 0/9 – 25 62 – 16.8 15 – 23

Soft (Tub) 0.3- 1.4 1.9 – 10.2 5 – 14

Pancakes 3.1 2.0

Chocolate Bar 0.2 0.6

Peanut Butter 0.1 0.4


Trans Fatty Acid content of Indian Food Items

Type of

Food

Trans Fatty Acid Content

Fried

Foods

Cooked purely in

Vanaspati (Partially

Hydrogenated Fat)

Cooked in combination

of Vanaspati and

Refined vegetable oil

g/typical

serving

(g/100 g) g/typical

serving

(g/100 g)

Parantha 3.9 7.8 - -

Puri 3.4 8.6 2.2 5.5

Bhatura 5.2 9.5 1.7 3

Dosa 1.7 4.3 0.3 0.8

Tikki 6.1 7.6 - -

Samosa 3 5 1.5 2.4

Pakora 2 6.7 0.8 2.7

Vegetable

Pulao

2.9 2.9 - -

Dessert

(Halwa)

3.6 3.6

Conclusion

1. It is a proven fact now that trans fatty acid are more harmful

than saturated fatty acid, hence the reduction of trans

fatty acid in diet is advisable. In view of severe metabolic

problems in Indians, it is suggested that:

• The use of TFA be banned from all prepackaged

products

• “TFA free” labeling should be mandatory on commercial

food products

• Awareness about trans fats should be spread to all, also

to those in low SES

• Warning with color coding for easy interpretation of

risk should be used.

2. Effective 1st Jan 2006 the US FDA (Food Drug Administration),

requires food companies to list trans fat content separately

on the Nutrition Facts panel of all packaged foods. This

should be strictly followed in Indian market as well.

3. The American Heart Association advices consumers to read

labels before buying oil or margarine. The recommendations

are to choose spreads that have liquid vegetable oil as the

first ingredient and no more than 2 grams of saturated fat

per tablespoon.

4. Some liquid and soft tub margarines are low in both

saturated fats and trans fats (some are trans–free). These are

preferable.


Arko Pratim Banerjee Physiotherapist & Ergonomist Department of Physiotherapy & RehabilitationPushpanjali Crosslay HospitalVaishali, Ghaziabad (NCR)

Shuchita Bansal Head & ConsultantDepartment of Physiotherapy & RehabilitationPushpanjali Crosslay HospitalVaishali, Ghaziabad (NCR)

Office Ergonomics

Arko Pratim Banerjee and Shuchita Bansal

Abstract

The present paper outlines a study carried out at the Pushpanjali Crosslay Hospital on work related musculoskeletal disorders (WMSDs) experiences by the administrative staff. WMSDs are produced as a result of interplay of physical, organizational, psychosocial, individual, and sociocultural factors. In this study, the individual, organizational and environmental factors were investigated for their effect on physical and cognitive status of the employees. The assessment of risk factors was followed by application of appropriate control measures for the tasks and reducing the risk of WMSDs. Based on the findings, several controls were recommended at the individual, organizational and environmental levels. The Department of Physiotherapy (in collaboration with the Department of Dietetics) to evolve a physical fitness program to decrease the cases of lifestyle diseases/disorders.

Vibration

Aim and Objective

1. The aim of the study was to observe, analyze and investigate the risks of possible WMSDs in various tasks by the administration department personnel of Pushpanjali Crosslay Hospital.

2. The assessment of risk factors was followed by application of appropriate control measures for the tasks and reducing the risk of WMSDs.

Introduction

The primary concern for today’s industries and organizations are injuries that are caused at the work place. These injuries are hence termed as work-related musculoskeletal disorders (WMSDs). Certain jobs expose the worker to multiple risks such as repetition, awkward postures, vibration, forceful movements, heavy lifting, etc. These factors lead to cumulative trauma over time and finally lead to WMSDs. WMSDs are produced as a result of interplay of physical, organizational, psychosocial, individual, and sociocultural factors. In this study, the individual, organizational and environmental factors were investigated for their effect on physical and cognitive status of the employees.

Sample

The administrative staff of the Pushpanjali Crosslay Hospital formed the sample of the study. In this hospital the various sub-departments which come under the administration department are human resource, finance, operations, information technology, etc. Though the departments have different roles to play, the mode of working is fundamentally similar to any modern-day office, which is computer related work. The work shift is generally of 8 hours for each employee with one meal break.

Hypothesis

There is a large magnitude of risk factors for work related disorders associated with these tasks. Each task has its own set of risk factors ranging from awkward postures, repetitive movements, static postures, etc. This provided an outsized scope to estimate the status of occupational health and safety in these tasks and also bring in the opportunity to implement better controls to reduce the effect of the risk factors. Poor lifting Repetitive work

Awkward posture


Methodology1. Tools

• Questionnaire (self assessment)• Video camera (interview recording)• Still camera (worksite assessment)• Paper based assessment tool (Man-Task-Tool)

2. Composition of the taskThe most common task carried out in this part of the organization is data entry (by typing).Other duties included:

• Field job• Paper work• Data analysis• Call attending

3. Physical Task AnalysisThis field of work has a high workload and can be extremely taxing, both physically as well as mentally. Sedentary life style and poor social and peer support often make it difficult to handle the stress.

Observation of the tasks in progress and use of photography was helpful in identifying the various risk factors present in this section of the hospital.

The most common tasks carried out at the administration block are using phone, Data entry (typing), Paper work and Field work. These specific tasks were evaluated for their effect on various body parts and the extent of the risk using a manual handling tool – Man-Task-Tool.

4. Cognitive Task Analysis

The source of data to assess the cognitive behavior was obtained from the interviews and questionnaire. The think out loud protocol and interview was helpful in gaining the insight of the cognitive behavior process the employees had at work.

Moreover, the employees frequently need to move around by pushing and pulling the chair and also require reaching out to use frequently required tools. A reasonable amount of multitasking is also present at these work-stations.

Results - Problem List

The observation of the employees at work was helpful in recognizing the risk factors associated with the work, represented in Table 1.

Table 1: List of risk factors work-related musculoskeletal disorders and related evaluation

Risk factors for WMSDs Administrative Block

Awkward Posture +

High Workload +

Monotonous Work +

Forceful Movements +

Static Work Postures +

In addition to these, the chairs do not adapt to everyone’s body size and necessities. The work surface depth is 1 foot and does not allow placing the forearm and wrist in supported position when using the mouse and keyboard. The distance of the monitors from the eye is not sufficient and leads to eye strain.

The placement of the desk and shelves in the cubicles makes it difficult to access certain commodities. There are high chances of trips and falls in the cubicles because of the haphazard placement of files and folders. The interviews conducted for the employees showed that the departments were understaffed (at the time of the study).

The result accumulated for the physical tasks with the man-task-tool is presented in Table 2.

Table 2: Result of Man-Task-Tool

Risk on

Task Neck, Shoulders and Upper back

Elbow, Wrist and Hand

Low Back Leg, Knee and Foot

Using Phone

Medium Medium Low Low

Typing (Data Entry)

Medium Medium Medium Low

Paper Work

Medium Medium Medium Low

Field Work

Low Low Medium Medium

The main areas of problem in the cognitive task section are:• Lack of motivation • High stress environment• High time pressure• Lack of control on job • No supervision - no line manager• Lack of peer support – no team effort, internal conflict• Boredom – no job rotation• Fatigue – high physical work

Discussion Stress and fatigue are the most common terms used in the modern industrial culture. Humans cognitively assess stressors as potential or real threats, and the brain then organizes the physiologic and behavioral response to the stressors . Fatigue is the perception that one is increasingly unable to maintain a predetermined level of behavioral efficiency in the face of continuing demands to do so.

The high stress environment, monotonous and repetitive work may lead to boredom and decrease in alertness. A decline in the alertness may cause fatal accidents. The high time pressure with limited supervision or management causes a decrease in productivity. Though there is ideally one break (30 minutes) in between the shift for lunch and a tea break, the employees are exhausted and less alert by the end of the day. The capability to answer cognitive questions while performing the work decrease as the day passes. Therefore, short breaks with short periods of work can be better accepted than long shifts with long breaks .

The stressors can be divided into environmental (high and low temperatures, humidity, poor air quality, improper lighting while using computers, power cuts), psychological (high task demands,


low job control) and psychological plus physiological (fatigue). Interplay of these stressors produces a poor working condition. Eventually there is a decrease in the coping mechanism to the threats and challenges put by these stressors and may exacerbate physiological and/or psychological ailments.

The effect of the various stressors as well as managerial condition has a great effect on the job performance. The lack of comfortable

furniture in few sections, extreme temperature, high task load and time pressure, no supervision or proper management, mundane and repetitive tasks without job rotation, lack of control on job, etc. interplay to produce a deprived working environment and thus an unsafe and less productive workplace. Therefore, there is need for interventions in this industry at various levels. With the help of the top management, few changes are already in effect and few more are in process. At present, the company is structuring the safety standards of the hospital. The lack of synchrony is between the company and the employees, the workers’ low awareness of the safety procedures of the company are being sorted out.

A detailed behavioral and cognitive task analysis is required to diagnose even the minor unseen problems. There is a scope of future study to diagnose and recommend concrete interventions and modifications. A department wise investigation will follow this initial study to look into the ergonomic flaws.

Recommendation Numerous controls were recommended at the individual, organizational and environmental levels. In particular, the development of a physical fitness program at the Department of Physiotherapy (in collaboration with the Department of Dietetics) was recommended to decrease the cases of lifestyle diseases/disorders.

Moreover, taking short breaks to stretch the muscles and relaxing during the work is also an effective control. Proper training programs (pre-employment as well as on job) require to be installed.

The Line manager/ team leader should be in a position to define and supervise the tasks. Task rotations and coordination between the team members can be more synchronized with the help of a line manager/ team leader (already in effect).

Modification of the workstations is also recommended. The workspace design should ideally:• avoid static postures, • avoid awkward postures, • avoid overloading of muscular system,

• avoid unnatural postures,• aim at best mechanical advantage,• maintain proper sitting posture,• permit the necessary work points to be adequately visible

with the head and trunk upright,• match the job demand to operator capacity,• Permit change of posture.

ConclusionAfter the assessment of the workplace, the result showed that this hospital may be at a risk for hazards and injuries. The loopholes at the various levels are numerous. According to the “Swiss-cheese model”, the loopholes just need to align in a straight line for any hazard to occur (Figure 1).

Figure 1: Swiss-cheese model

The effect of the various stressors as well as managerial condition has a great effect on the job performance. Interplay of these risks produce a poor working environment and thus, an unsafe and less productive workplace. Therefore, implementing intervention in this industry at various levels, beginning from the physical level of the ladder up to the political level is a necessity.

Physical interventions are also important and should be next on priority. Implementing the physical modification would automatically improve the conditions at the other levels to some extent. The lack of synchrony between the company and the employees and the safety procedures of the company not in total effect is the prime concern and has been well acknowledged by the top management.

The characteristics of Swiss cheese is to have holes, hence there will always be loopholes in all the levels of defenses. The interventions and policies just need to plug as many loopholes as possible and not let the loopholes align in a straight line. No doubt that small incidents will continue to happening regularly at the workplace, since they are just the inevitable holes in the Swiss cheese, but with adequate precautions a major hazard can be prevented.

References1. Cohen, et al., 1997 Element of ergonomics programs

(NIOSH).2. Anderson, et al., 1997 Musculoskeletal disorders and

workplace factors (NIOSH).3. Dinges, DF Stress, Fatigue, and Behavioural Energy.

Nutrition Reviews; Jan 2001; 59, 1; ProQuest Medical Library pg, S30.

4. Sjogaard, G and Jensen, BN Low Level Static Exertions. The Occupational Ergonomics Handbook. Boca Raton: CRC Pg. 247-259.

5. Allyn and Bacon 1994 Chapter 17 Antropometrics and workspace design (369-395).

Causes of Slip, Trips and Falls

Radiology September 2010

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