Post on 12-Nov-2014
Radiology (Dra. Bandong)
Pleura, mediastinum…
05 July 2008
Anatomyo a space within the thoracic cavityo bounded by:
- anterior sternum- posterior vertebral bodies- superior thoracic inlet- inferior diaphragm- lateral parietal pleura
o divided into compartments by drawing a line from the sternal angle to the 4th thoracic intervertebral disk space
- area above superior compartment- area below inferior compartment
o anterioro middleo posterior
CT SCANo is the imaging modality of choice for diagnosis, staging, and
follow up of patientso offers the advantage of better localization and
characterization of the disease processo it can demonstrate compression and involvement of the
adjacent structures in the mediastinum better than plain films.
Normal Thymuso Lies in a retrosternal location behind the manubriumo Commonly seen anterior to the proximal ascending aorta
and distal superior vena cavao Size of a normal thyroid is largets between 12-19 years
of age.
o Anteriorly by the sternumo Posteriorly by the pericardium, aorta, and brachiocephalic
vessels
Masses situated predominantly in the anterior mediastinal compartment (AMC)
A mass is considered to lie in the AMC when it is situated in the region anterior to the line drawn along the anterior border of the trachea and posterior border of the heart
Anterior Mediastinal Masso Thymus
- Thymoma – Most common- Thymic cyst- Thymolipoma- Thymic carcinoid- Thymic hyperplasia
o Lymphomao Germ cell tumor
- Teratoma- Seminoma- Shoriocarcinoma
o Thyroid- Goiter - Tumor
o Mesenchymal tumors- Leiomyoma- Liposarcoma
o Hemorrhage
NOTES:Mediastinal mass: Pulmonary mass:
o Margins are smooth o Spiculated margins o Bilateral o Unilateralo Loss of cardiac silhouette
1C ng 3B (jassie, viki, candz..ung iba support group..hehe) 1 of 14
Pleura
Anterior mediastinal compartment
o Widened mediatinum o Loss of cardiac
silhouette o Intact silhouette of
descending aorta
o Retrosternal area is filled with mass density
Anterior mediastinal mass
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ThymomaTeratomaThyroid nodule / goiterLymphoma
THYMOMAo Most common neoplasm of the anterior mediastinumo 30-35% are malignanto Commonly occur in patients >40y/oo Asymptomatico CXR:
- Found in anterior mediastinum to the ascending aorta above the right ventricular outflow tract and main pulmonary artery
- Maybe situated as low in the mediastinum as the cardiophrenic angles
o CT(Benign)- Well demarcated masses with homogenous
density- Uniform contrast enhancement- Have areas of decrease attenuation- Punctuate or ring like calcifications
o CT (Malignant)- Heterogenous attenuation- May obliterate adjacent mediastinal fat- May detect pleural spread
LYMPHOMA
2 types of lymphoma: Hodgkin’s (HL)
o Bimodal age distribution—25-30 y/o and >70 y/oo 67% intrathoracic involvement (anterior/ superior
mediastinal and hilar adenopathy) o 15-40% pulmonary involvement by:
- Direct extension form involved nodesPulmonary nodulesParenchymal consolidationPleural effusionSternal erosions
Non Hodgkin’s (NHL)o 4x more common than HLo 3rd most common childhood malignancyo More frequently fatal than HLo Middle medisatinum – most frequently involvedo Posterior mediastinum and cariophrenic angles can be
alteredo Appears as a single large conglomerateo Other common nodal signs involvement include
Lung parenchymaPleuraPericardium
o most are found in the anterior mediastinumo 20-40 yearso Divided into
seminomatous neoplasms (seminoma) non seminomas
Seminomatous neoplasm (Seminoma)o Most common germ cell tumoro most common primary malignant cell tumoro less aggressiveo secrete low levels of HCGo On CT:
large masses with sharply demarcated borderso Homogenous attenuation but may have hemorrhage and
necrosis
Germ Cell Tumors
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Non Seminomatous neoplasmo More aggressiveo Secrete high levels of fetoprotein and / or HCGo Teratoma
- Most common non seminomatous tumors- Most common mediastinal germ cell tumor- Benign: mature teratoma
MATURE TERATOMACXR: large, well demarcated, rounded masses
Located anterior to the root of the aorta and main pulmonary arteryCalcification, ossification or even teeth may be visible
CT: large cystic massThick, encapsulated wallMay enhanceMay contain curvilinear calcifications
MALIGNANT TERATOMACXR: more lobulated in outline
Rarely has calcifications and never has fat densityMetastasize to the lungs, bones or pleura
CT: typical mass has irregular border with thick capsuleEnhances with IV contrastAdjacent fat planes are obliterated
Extreme local invasion is common*In CT scan, this can be distinguished from thymoma and seminoma.
Masses predominantly in the MMC and PMC
A lesion can be considered to properly lie in the MMC or PMC when it is located between a line drawn through the anterior aspect of the trachea and posterior aspect of the heart and the line drawn through the anterior margins of the vertebral bodies
Middle and Posterior Mediastinum (MMC / PMC)
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NOTES:Posterior lesion – 20 to osseous; sarcoma involving
the vertebral columnMiddle lesion – esophagus, bronchogenic cyst
Middle MediastinumBoundaries by posterior margin of anterior division and
anterior margin of posterior division (malamang!)
Normal structuresHeart and pericardiumAscending and transverse aortaBrachiocephalic vesselsSVC and IVCMain pulmonary vesselsTrachea and main bronchiLymph nodes
Differential diagnosis of middle mediastinal massesLymphadenopathyBronchogenic cystVascular abnormalitiesPericardial cystTracheal tumor
Most common: aneurysm
Posterior mediastinumBoundaries bounded anteriorly by the posterior margin of
the pericardium and great vessels and posteriorly by the thoracic vertebral bodies
Normal structuresDescending thoracic aortaEsophagusThoracic dustAzygous and hemiazygousAutonomic nervesLymph nodesFat
Differential diagnosisNeurogenic tumorsParavertebral abnormalitiesVascular abnormalitiesEsophageal abnormalitiesLymphadenopathyNeurenteric cystBochdalek’s herniaExtramedullary hematopoeisis
*It is difficult to delineate middle to posterior mediastium.
CASE: An 87 year old woman presents with dysphagia
Radiographs show a homogenous mass in the middle / posterior mediastinum extending from the level of the aortic arch to the
diaphragm and displacing the esophagus to the right (residual contrast is evident in the esophagus from a barium swallow)
A CT scan just below the level of the carina reveals a hematogenous soft tissue mass with a central area of low attenuation (A). Note the markedly compressed esophagus (B). It is not possible to discern whether the mass is arising from the wall of the esophagus or the adjacent mediastinum. There is an incidental finding of calcified brachial plates (C)
Non contrasted chest CT demonstrating heterogenous appearing post. Mediastinal mass with punctuate calcifications which appears to extend into the neural foramina (see picture below)
*With contrast, there is enhancement of blood vessels and vice versa in non-contrast.
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Contrasted Chest CT demonstrating heterogenous appearing post mediastinal mass with punctuate calcifications which appears to extend into the neural foramina.
o Age: occur in young patients in the first 4 decades of life (young???)
o Gender: males and females equally affectedo Round, homogenous with widening of the neural forameno MRI: slightly brighter than muscle on T1
Very bright on T2 homogenous enhancement following gadolinium demonstration
Neuroblastoma
o Tricuspid valve regulates blood flow between RA and RVo Pulmonary valve controls blood flow from right ventricle
into the pulmonary artery which carry blood to the lungs to puck up O2
o Mitral valve lets O2 rich blood from lungs to pass from LA to LV
o Aortic valve opens the way for O2 rich blood to pass from LV to the aorta, the largest artery, where it is delivered to the rest of the body
During Diastole, atria and ventricles are relaxed and the AV valves are open. DeO2ated blood from the SVC / IVC flows to the RA. The open ______ atrioventricular valves allow blood to pass through the ventricles. During systole, the ventricles contracts triggering the atria to contract. The RA empties its contents into RV. The tricuspid valve prevents blood from flowing back into the RA.
NOTES:Common Imaging modalities:
a. Ionizing radiation – Radiography, CT, Nuclear Scintigraphy
b. Non-ionizing radiation – MRI and 2D Echo
NEUROGENIC TUMORS
CARDIAC IMAGING LECTURE
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This coronal MRI shows a somewhat anterior plane of the heart. The RV and proximal pulmonary artery is well defined. Portions of the SVC and RA are also visible.
This axial MRI shows the main and right pulmonary artery crossing under the aortic arch (medyo malabo, pxenxa)
This sagital MRI shows the mid-section of the LV, defining the interventricular septum of the myocardium and the lateral wall.
Cardiac Borders: (see picture above)Right side – SVC and RALeft side – aorta, aortic arch, pulmonary artery, LA, LV
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The right ventricle and its outflow tract are seen as one continuous structure.
Calcium Scoreo Identifies calcification of coronary arterieso Screeningo Increased calcification = MI
The widest diameter of the heart compared to the widest internal diameter of the rib cage
Get the diameter of the heart then divide it to the diameter of the entire thoracic area within the confines of the thorax (ribs not included)
Normal Cardio-thoracic ratio:o Adults - < 0.5o Children – 0.55
o
Sometimes, CTR is more than 50% BUT heart is normalExtracardiac causes of heart enlargement
Portable AP films
ObesityPregnancyAscitesStraight back syndromePectus excavatum
CTR is less than 50% BUT heart is abnormalObstruction to outflow of the ventriclesVentricular hypertrophyMust look at cardiac contours
Here is an example of a heart which is < 50% of the CTR, in which the heart is still abnormal. This is recognized because there is an abnormal contour to the heart.
Cardiac contours: Ascending aorta
o Enlargement 20 to atherosclerosiso Enlargement is called: Double density sign
Left atrium Aortic knob
o Normal: not > 0.35 mmo If enlarged, there is atherosclerotic aortao >0.5 cm: aneurysm
Pulmonary arteryo Congenital diseaseo Dilatation of artery
CARDIO THORACIC RATIO
CARDIAC CONTOURS
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DOUBLE DENSITY OF LA ENLARGEMENT
Two shadows: the yellow arrow pointing to the LA and the red arrow to the RA, overlap each other where the indentation between the ascending aorta and the right heart border meet.
Aortic knob o The first bump on the left sideo Can be measured from the lateral border of air by the
trachea to the edge of the aortic knob.o Enlarged by
Increased pressureIncreased flowChanges in the aortic wall
Main Pulmonary ArteryThe next bump down is the main pulmonary artery and is the keystone of this system
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Two major classificationso Main pulmonary artery projects beyond the tangent line
Increase pressureIncrease flow
NOTES:Small pulmonary artery: TOF, Truncus arteriosusApex of ventricle goes down: Enlargement of left ventricleApex of ventricle goes up: Enlargement of right ventricle
o Main pulmonary artery more than 155mm away from the tangent line.
Because MPA is small or absentBecause tangent line is being pushed away from the
MPAExamples: small pulmonary artery
Truncus arteriosusTetralogy of fallot
Left atrial enlargement Concavity where LA will appear on the L side when enlarged
Which ventricle is enlarged?If heart is enlarged and main pulmonary artery is bigRV is enlarged
Five states of the Pulmonary Vasculature:
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Normal (more vessels should be seen in inferior part of the lungs); with enlargement of upper lobe, there is cephalization.
Pulmonary venous hypertension Pulmonary arterial hypertension Increased flow Decreased flow
What we’re going to evaluateRight descending pulmonary arteryDistribution of flow in the lungs
Upper vs. lower lobesCentral vs. peripheral
Right Descending Pulmonary Arteryo Serves right, middle and lower lobes
Normally should not be more than 17mm in diameter. (Diameter is measured before the bifurcation)
1. Normal Distribution of flow (U / M/ L lobes)o In erect position, blood flow to the bases is > than flow
to the apices
o Size of vessels at the bases is normally > than the size of vessels at apex
o You cant measure the vessels at the left because the heart blocks them
*Central Vs. Peripheral distribution of flow: divide lungs vertically into 3. Outer 2/8: here, you seldom see vascular markings. If present, there is congestion.
2. Pulmonary Venous Hypertensiono Has cephalization (more vessels in upper lobes than
lower lobes)o Increased vascular markings
3. Pulmonary Arterial hypertensiono RDPA > 17 mmo More central vessels are dilatedo Dilatation of right descending pulmonary arteryo Main pulmonary artery projects beyond the tangent line
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o Rapid cutoff on size of peripheral vessels relative to the size of central vessels
o Central vessels appear to large for size of peripheral vessels which come from them = Pruning
4. Increased flowo Distribution of flow is maintained as normalo Gradual tapering from central to peripheralo L lobe bigger than U lobe
5. Decreased flowo Unrecognizable most of the timeo Small hilao Fewer than normal blood vesselso No vessels in lower lobes (which is normally present)
o Causes: coronary artery diseaseHypertensionCardiomyopathyValvular lesion
AS, MSL to R shunts
o Clinical: left sided heart failure:Shortness of breathParoxysmal nocturnal dyspneaOrthopneaCough
right sided heat failure:Edema
Left Atrial PressureCorrelated with pathologic Findings
Normal 5-10 mm HgCephalization 10-15 mm HgKerley B lines 15-20 mm HgPulmonary Interstitial edema 20-25
Pulmonary Alveolar edema >25
*Normal pulmonary capillary hydrostatic pressure: about 7 mmHg Normal colloid oncotic pressure: 11 mmHg
CONGESTIVE HEART FAILURE
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Kerley A lines – near hilum, longer B linesKerley B lines – sign of interstitial edema, located in the basesKerley C lines – does not exist
Keeping lungs dry
Pulmonary Interstitial Edema Fluid present in minor fissure Linear opacities in bases: Kerley B lines X-ray Findings
o Thickening of the interlobular septa- Kerley B lines
o Peribronchial cuffing- Wall is normally hairline thin
o Thickening of the fissures- Fluid in the subpleural space in continuity
with interlobular septa Pleural effusions
Kerley B lineso B = distended interlobular septao Location and appearance
Bases1-2 cm long
Horizontal in directionPerpendicular to pleural surface
Kerley B lines are short, white lines perpendicular to the pleural surface at the lung base
Kerley A and C lineso A = connective tissue near bronchoaretrial bundle distendso Location and appearance
Near hilumRun obliquelyLonger than B lines
o C = reticular network of lines**C lines probably don’t exist (huh??)
Kerley A and C lines form a pattern of interlocking lines in the lung
o Interstitial fluid accumulates around the bronchi
PERIBRONCHIAL CUFFING
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o Causes thickening of the bronchial wallo When seen on end, it looks like little “doughnuts”
Peribronchial cuffing results when fluid thickened bronchial walls become visible producing doughnut- like densities in the lung parenchyma
Fluid in the fissureso Fluid collects in the subpleural space
- Between visceral pleura and lung parenchymao Normal fissure is thickness of a sharpened pencil lineo Fluid may collect in any fissure
- Major, minor, accessory fissure, azygous fissures- Minor fissure: thickened fluid- Pleural effusion: there is obliteration of costophrenic
sulcus
o Laminar effusions collect beneath visceral pleuraIn loose connective tissue between lung and the pleuraSame location for “pseudotumors”
Laminar pleural effusion can be difficult to see. Aerated lung should normally extend to the inner margin of the ribs. The white band of fluid seen here (white arrow) is a laminar effusion separating aerated lung from the inner rib margin
o If hydrostatic pressure >10mm Hg fluid leaks into the interstitium of the lung
o Compresses lower lobe vessels first- Perhaps because of gravity
o Resting upper lobe vessels ‘recruited” to carry more bloodo Upper lobe vessels increase in size relative to the lower lobe
Cephalization means pulmonary venous hypertension. As long as the person is erect when the chest X-ray is obtained
TypesPLEURAL EFFUSION
CEPHALIZATION
PULMONARY EDEMA
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o Cardiogenico Neurogenico Increased capillary permeability
Congestive heart failureXray patterns1. Interstitial
o Thickening of the interlobular septa- Kerley b lines
o Peribronchial cuffing- Wall in normally hairline thin
o Thickening of the fissures- Fluid in the subpleural space in continuity with
interlobular septao Pleural effusionso Cephalization
2. Alveolaro Acinar shadowo Outer third of the lung frequently spared
- Bat-wing or butterfly configurationo Lower lung zones more affected than uppero Massive pleural effusion
In pulmonary alveolar edema, fluid presumably spills over from the interstitium to the air spaces of the lung producing a fluffy configuration “bat wing” like pattern of disease
Pulmonary Alveolar edema Clearingo Generally clears in 3 days or lesso Resolution usually begins peripherally and moves centrally
Differential diagnosis
Cardiac Renal ARDSKerley B lines and peribronchial cuffing
30% 30% None
Distribution of Pulmonary Edema
Even 90%
Central 70%
Peripheral in 45%Even in 35%
Air bronchograms 20% 20% 70%
Pleural Effusions 40% 30% 10%
CHF in Chronologic Sequence(e2 po ung last topic, pero hindi n nmin nkuha..kung meron sa inyong may notes pshare nlng.
EXCLUSIVE WONCEE TRANS …effort as in…