Common Nuclear Medicine Imaging_Part1_2015

Common Nuclear Medicine Studies I

Jiraporn Sriprapaporn, M.D.

Division of Nuclear Medicine

Department of Radiology

Siriraj Hospital

June 2015 Common NM Studies By J. Sriprapaporn

Common nuclear medicine studies 1

Bone scan, Bone Mineral Density (BMD)

GI bleeding studies

Hepato-biliary imaging

Cardiac Imaging

Common nuclear medicine studies 2

Lung scan

KUB

Oncology (SPECT & PET)

Scope

Common NM Studies By J. Sriprapaporn

Can explain what Nuclear Medicine is.

Can explain principle or mechanism of each

radionuclide imaging

Can describe important clinical indications

and interpretation.

Can apply the studies to fit the real life conditions in the future !!!.

Objectives


Introduction to Nuclear Medicine

Bone scan

GI bleeding studies


Cardiac Imaging


TYPE OF NM IMAGING

•Conventional NM imaging -SPECT or SPECT/CT, planar, whole-body imaging

•Positron emission tomography (PET) PET/CT

Nuclear medicine is a medical specialty which uses very small amount of a radioactive substance or a chemical compound labelled with a radioactive substance, called “radiopharmaceutical” or tracers to image or treat diseases.


Endocrinology: Thyroid scan, Parathyroid scan

Cardiovascular system: Myocardial perfusion scan, Radionuclide venography

Genitourinary system: Renogram, Testicular scan, Radionuclide cystography

Pulmonary system: Perfusion/ Ventilation lung scan

Skeletal system: Bone scan

Gastrointestinal system: Liver scan, Hepatobiliary scan, GE reflux study

Tumor imaging: Ga-67 scan for Lymphoma, I-131 scan for pheochromocytoma, Tc-99m MIBI for parathyroid adenoma


Functional*

Sensitive

Quantitative

Very safe

Minimally invasive

Low radiation exposure

Screening

Follow-up


Not widely available

Give minimal radiation

Generally non-specific

Require NM instrument &

radiopharmaceuticals

Higher cost than routine X-ray or U/S


Tc-99m pertechnetate*

I-131*

Tl-201

Ga-67

In-111


Available

Low cost

Pure gamma emitter

Optimal gamma energy (100-200 keV) *140

Optimal physical half life *6 hr

Safe

Chemically active various radiopharmaceuticals

* Tc-99m is the most ideal agent !

Tc-99m


Radiopharmaceutical

Patient

Gamma Camera

Images Common NM Studies By J. Sriprapaporn

Planar gamma camera

SPECT = Single Photon Emission Computed Tomography

PET = Positron Emission Tomography

PET/CT Common NM Studies By J. Sriprapaporn

SPECT

CT

Fused

SPECT

CT

Fused

Pheochromocytoma of right adrenal gland

Stress fracture at left tibia


PET:Metabolic imaging

Using positron-emitting

radionuclides

Biological tracers (C, N, O, F)

More sensitive

Better images

Whole body evaluation



Bone scan and BMD Testing

GI bleeding studies

Hepatobiliary imaging

Cardiac Imaging


Objectives

Detection, staging and follow-up of bone metastasis

Differentiating between osteomyelitis and cellulitis

Determination of bone viability

Evaluation of difficult fracture (stress fracture, fracture in battered child)

Evaluation of prosthetic joint problems (loosening, infected prosthesis)

Evaluation of bone pain in patient with normal plain radiograph (unexplained bone pain)

Radiotracer: 99mTc-MDP (methylene diphosphonate)

excreted via urine

Patient preparation: None, prefer good hydration


Bone scan

Adsorption to the hydroxyapatite hydroxyapatite crystal

Increased uptake

Increased blood flow

Increased osteoid formation

Increased mineralization of osteoid

Interrupted sympathetic nerve supply

Bone scan: Mechanism of uptake


Bone scan

Advantages:

Sensitive > plain X-ray *

Whole-body evaluation

Low radiation

Disadvantages:

Nonspecific (if no specific pattern)

Thus, interpretation of bone scan

requires clinical & RAD correlation, as well as F/U.


Prostate

Lung

Breast

Neuroblastoma

Tumors commonly metastasize to bone


Normal

Symmetry: active bone

Child – epiphyseal growth plates of long bone

Abnormal

Hot lesions : bone metastasis, primary bone tumor, osteomyelitis, trauma

Cold lesions : purely osteolytic bone metastasis (ex. RCC, MM, neuroblastoma, thyroid), overlying artifact, post-RT, vascular compromised (AVN)

Interpretation

Cold lesions are hard to see less sensitive on bone scan !


Bone Scan

ANT POST ANT POST


The most common and

typical pattern of bone

metastases is that of

multiple randomly

distributed foci of increased

uptake, usually in the axial

skeleton following the distribution of bone marrow

Typical Pattern of Bone Metastases


Cold metastatic lesions

(arrows) in a patient with

renal cell carcinoma of the

right kidney which was surgically removed

Cold Metastatic Lesions


Normal PED images Rib Fractures Rib Metas. AVN s/p ERT

Bone Scan Images


Diffusely increased axial skeletal

uptake with low or no visualized

renal uptake

Diffuse bone metastasis

Primary: prostate*, breast, lung

Metabolic bone disease

Hyperparathyroidism

Renal osteodystrophy


Image looks like progressive metas. but it actually represent

increased reparative process due to therapeutic response*.

This phenomenon may last upto 3-6 months post systemic

treatment eg. CMT, hormonal Rx.

Early change on bone scintigraphy a marker for a

successful cancer treatment. [Coleman RE JNM 1988]

F/U bone scan 6 months after treatment more accurate.

Flare phenomenon


Flare phenomenon

Baseline 3 mo. post-CMT 6 mo. post-CMT

Phase 1; Vascular phase: 60 s dynamic immediately pi.

Phase 2; Soft-tissue (blood-pool) phase: 5 min pi.

Phase 3; Delayed (bone) phase: 3 hr pi.

INDICATIONS: Evaluate diseases affecting blood flow

Infection: DDx acute osteomyelitis vs cellulitis

Avascular necrosis

Painful hip prosthesis: DDx loosening VS infected prosthesis

Sport injury: Stress fracture, stress injuries

Tumors: Primary tumor

Others eg. Reflex sympathetic dystrophy (RSD) Common NM Studies By J. Sriprapaporn

Vascular phase

Soft-tissue

delayed 3-hr


19-yo male

Heavy running 10 Km/d for a few

months

Pain at left shin for a few weeks.

Plain film was negative.

MR suspected tumor.

3-phase BS proved to be stress

fracture.

Thus, bone biopsy was cancelled.

Stress fracture at left tibia

Sriprapaporn J. Siriraj Med J 2012;64:163-166



Bone scan

GI bleeding studies


Cardiac Imaging


Instrument: Dual X-ray absorptio-

metry (DXA)

Aims:

To diagnose osteoporosis (OP)

To predict fracture risk

To monitor therapy for OP


Bone Mineral Density Testing

Lumbar spine Femur (Hip) Forearm

(L1-L4) (Femoral neck, total femur) (33% Radius)

Skeletal Sites to be Measured


DXA: Patient Positioing

2012 Ramos

Lumbar Spine Femur-Hip

Forearm


Bold = New


ISCD 2013: Indications for BMD Testing

• All women age 65 and older

• All men age 70 and older

• Adults with a fragility fracture

• Adults with a disease or condition associated with low bone density

• Adults taking medication associated with low bone density

• Anyone being treated for low bone density to monitor treatment effect

• Anyone not receiving therapy, in whom evidence of bone loss would lead to treatment

• Women discontinuing osteoporosis treatment.


Formulas & Definitions

BMD = BMC/Area (g/cm2)

DXA is the gold standard method for measuring BMD, which the central BMD of lumbar spine & hip is used to Dx OP.

OP =

BMD by QCT is measured per volume (g/cm3)

T-score is used in postmenopausal women or men > 50 yrs

Is used to Dx OP (WHO criteria)

Z-score is used in premenopause or men < 50 yrs

Is not used to Dx OP

Z-score <-2 : BMD is lower than expected range for age.

T-score= number of SD compared to young adult pop

Z-score = number of SD compared to same age population


BMD Reporting in Postmenopausal Women and in Men Age 50 and Older

Classification T-score

Normal −1 or greater

Osteopenia (low bone mass) Between −1 and −2.5

Osteoporosis −2.5 or less

Severe osteoporosis −2.5 or less and fragility fracture

Use of the Term “Osteopenia” • The term “osteopenia” is retained, but “low bone mass” or “low bone density” is preferred. • People with low bone mass or density are not necessarily at high fracture risk.

Common NM Studies By J. Sriprapaporn *T-score: Use lowest BMD of hip and spine


Bone scan and BMD Testing

GI bleeding studies


Cardiac Imaging


Indications : To detect and localize bleeding point-lower GI bleeding

Radiotracer : Tc-99m labelled RBC

Patient preparation : NPO

Interpretation : Positive = extravasation of the radiotracer into bowel lumen

Criteria for diagnosis of GI bleeding

- Focal activity appears & conforms to bowel anatomy

- Activity increases overtime

- Activity movement along the bowel loop

- Movement may be anterograde or retrograde

GI Bleeding Scintigraphy (Red blood cell scan)


GI Bleeding at hepatic flexure of colon

Bleeding pattern:

• Central abdomen Small bowel

• Peripheral abdomen Large bowel


Interpretation of GI bleeding

False Positive

• Free Tc-99m pertechnetate

• Urinary tract activity

• Uterine or penile blush

• Accessory spleen

• Hemangioma

• Varices

False Negative

Bleeding rate too low

Intermittent bleeding


Tc-99m RBC Scan vs Angiography

RBC Scan

• For diagnosis only

• Less anatomical details

• More sensitive (bleeding rate 0.1-0.5 cc/min)

• Good for intermittent bleeding

• Less invasive

Angiogram

For diagnosis & treatment

Better anatomical details

Lower sensitive (detect ได ้ตอ้งbleeding rate > 10 เทา่ของ RBC scan)

Needs active bleeding

More invasive


Emergency condition

Nuclear scan has role only for lower GI bleeding

Can be requested during the day time (No OT

service)

Use radionuclide bleeding scan for screening test

(sensitive > angiogram).

If radionuclide scan is negative angiogram would be negative.

GI Bleeding Scan


Meckel’s diverticulum = Remnant of omphalomesenteric duct

Gastric mucosal lining*

Common presentation: painless lower GI bleeding in small children

Imaging:

Principal: Localization of ectopic gastric mucosa

Patient preparation:

• NPO at least 4 hr.

• Can perform when bleeding is inactive,

• Avoid barium / laxatives / endoscope on the day prior the study.

• Pharmacologic augmentation - cimetidine, ranitidine

Radiopharm: Tc-99m pertechnetate IV.

Sequential imaging for 1-2 hr.

Sen 85%, spec 95%

Meckel’s Diverticulum Scan

Disease of TWO


Meckel’s Diverticulum

Bladder

Stomach

M

Stomach

U. Bladder


Meckel’s diverticulum

False Positive

• Focal hyperemia from

infection/inflammation/vascul

ar structure

• Urinary tract activity

• Intussusception

False Negative

Small amount of gastric

mucosa

Rapid washout of Tc-99m pertechnetate

Positive: Focal increase activity appears at the same time as

stomach, most common at RLQ.


Radionuclide Studies for Lower GI Bleeding

GI Bleeding Scan

• Generally for adults

• Tc-99m labelled RBC

• Mechanism: Extravasation of the radiotracer into bowel lumen

• Results: Not specific

• Active bleeding during the scan is required.

Meckel’s Scan

Generally for children with suspected for Meckel’s bleeding

Tc-99m pertechnetate

Mechanism: ectopic gastric mucosa localization.

Results: Specific

Active bleeding during the scan is unnecessary.



Bone scan

GI bleeding studies


Cardiac Imaging


Indications :

Biliary tract obstruction

Biliary atresia (BA)

Acute cholecystitis

Choledochal cyst

Bile leak

Radiotracer : 99mTc-DISIDA IV

Patient preparation :

NPO 4-6 hr.

Phenobarb 5 mg/Kg/d X 5 days prior to study for BA

Hepatobiliary Scan (DISIDA Scan)


Principles of test: Uptake in hepatocytes & then excreted via the biliary tract.

Imaging Technique

Dynamic study for at least 1 hour +/- delayed imaging

upto 24 hrs in cases with cholestatic jaundice.

Visualization : Liver and biliary system including

gallbladder until excretion into small bowel (normal =

within 1 hour)

Hepatobiliary Scan


Normal HB Scan

Visualization :Liver and biliary system including Right & left hepatic ducts

Common hepatic duct

Common bile duct

Gallbladder

Until excreted into small bowel

Within 1 hour

Tc-99m DISIDA


DDx biliary atresia & neonatal hepatitis HB scan: Sen 97-100%, spec 82-94%, and accuracy

of 91% Findings of neonatal hepatitis

Variable hepatic uptake // Fn. Visualization of GB Presence of radioactivity excretion into small

bowel

Findings favor BA Good hepatic function No radioactivity excretion into small bowel upto

24 hrs

Neonatal Jaundice

Late case with severe hepatic impairment really problematic! Common NM Studies By J. Sriprapaporn

Biliary atresia: No bowel activity at 24 hours.

DDx : Severe neonatal hepatitis with severe hepatic impairment

Biliary Atresia

Early images 24-hr image



Bone scan

GI bleeding studies


Cardiac Imaging


Radionuclide angiocardiography

Equilibrium gated blood pool

study (GBP) or Multiple Gated Analysis (MUGA study)

Myocardial perfusion imaging**

Cardiac Imaging


Tracer: Tc-99m labeled RBC

Findings

Cardiac shape and size

Wall motion: global, regional

Stroke volume (ED counts - ES counts)

Ejection fraction (EF): LV, RV

EF = (ED counts - ES counts) / (ED counts)

Equilibrium MUGA

• Normal LVEF is typically 60-70 %. •LVEF < 50% is definitely abnormal

• Normal RVEF should > 41%. Common NM Studies By J. Sriprapaporn

Findings (cont.)

LV outputs

Phase analysis: dyskinesis eg. aneurysm

Amplitude analysis

Diastolic ventricular function

Indications

DDx CAD from cardiomyopathy

Plan Rx valvular heart disease

Monitoring cardiac toxicity from chemotherapeutic agent eg. adriamycin (highly reproducible)

Equilibrium MUGA


Noninvasive tool for evaluation of myocardial

function & perfusion Diagnose coronary artery

disease (CAD)

Coronary stenosis < 50% No hemodynamic

significance

During stress Detect > 50 % stenosis

At rest Detect > 90% stenosis

Myocardial Perfusion Imaging


Tests

Sensitivity

(%)

Specificity

(%)

Reference

Resting EKG 45-50 85-90

Koskinas KC, ESC Council for Cardiology

Practice2014

Exercise EKG 50-68 77-90 Vesely MR, JNM 2008

SPECT (1) 86.0 74.0 Underwood SR, EJNMM 2004, metaanalysis

SPECT (2) 88.3 75.8 Parker MW, Circ Cardiovasc Imaging 2012

PET 92.6 81.3 Parker MW, Circ Cardiovasc Imaging 2012

Noninvasive Tests for CAD


Diagnosis of coronary artery disease***

-Presence

-Location (coronary territory)

-Severity

Help distinguish viable ischemic myocardium from scar

Risk assessment and stratification

-Postmyocardial infarction

-Pre-operative for major surgery in patients who may be at risk for

coronary events

Monitor treatment effect

-After coronary revascularization

-Medical therapy for congestive heart failure or angina

-Lifestyle modification

Myocardial Perfusion Imaging:

Indications

SNM Procedure Guideline: Myocardial Perfusion Imaging- http://interactive.snm.org/docs/pg_ch02_0403.pdf

Preop screening


Tracers:

Thallium-201 (Tl-201)

Tc-99m MIBI (Tc-99m sestamibi, Cardiolyte)

Tc-99m tetrofosmin

Principle: Myocardial perfusion & myocardial viability*

Technique

Acquire rest & stress images

Stress: exercise or pharmacological tests (dipyridamole or

persantin, dobutamine, adenosine*)

MYOCARDIAL PERFUSION IMAGING


MPI with Exercise Stress Test


Imaging techniques

Planar images: 2D

SPECT images*: 3D

• short axis,

• long axis-LH, LV

Gated SPECT: contractile function (LVEF)

Interpretation

Compare between rest & stress images

• Fixed perfusion defect myocardial infarct

• Transient / reversible perfusion defect myocardial ischemia

MYOCARDIAL PERFUSION IMAGING


Planes & SPECT Images

Long Horizontal Axis

Long Vertical Axis

Short Axis


Normal Tc-99m MIBI MPI [Display Images & Walls]

STRESS

REST

STRESS

REST

Short Axis

Long Horizontal Axis

Septum Lateral

Apex Anterior

Posterior

Apex


Normal Myocardial Perfusion Scintigraphy

Polar Map (Bull’s Eye)


Fixed Defects: Apical & Septal Wall MI

Apical Infarct

Stress

Rest


Reversible Defect: lnferior Wall Ischemia

Stress

Rest


ECG-Gated Cardiac SPECT Anatomy & Function (wall motion & LVEF)


Gated Cardiac SPECT

Myocardial perfusion

LV mass/volume

ES/ED volume

Ejection fraction (EF)

Wall motion


Myocardial perfusion Imaging

Myocardial perfusion study is an noninvasive nuclear

medicine study that evaluate regional myocardial perfusion

as well as LV function-LVEF and regional wall motion in a

single setting.

Indication: Coronary artery disease*

Interpretation: Compare between rest & stress images

• Fixed perfusion defect myocardial infarct

• Transient / reversible perfusion defect myocardial ischemia


SUMMARY


• Principle

• Advantages & Disadvantages

Bone scan

GI bleeding studies

• RBC scan

• Meckel’s diverticulum

Hepatobiliary scintigraphy

Cardiac imaging


Common Nuclear Medicine Imaging_Part1_2015

Health & Medicine

Transcript of Common Nuclear Medicine Imaging_Part1_2015