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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
Common NM Studies By J. Sriprapaporn
Introduction to Nuclear Medicine
Bone scan
GI bleeding studies
Hepato-biliary imaging
Cardiac Imaging
Common NM Studies By J. Sriprapaporn
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.
Common NM Studies By J. Sriprapaporn
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
Common NM Studies By J. Sriprapaporn
Functional*
Sensitive
Quantitative
Very safe
Minimally invasive
Low radiation exposure
Screening
Follow-up
Common NM Studies By J. Sriprapaporn
Not widely available
Give minimal radiation
Generally non-specific
Require NM instrument &
radiopharmaceuticals
Higher cost than routine X-ray or U/S
Common NM Studies By J. Sriprapaporn
Tc-99m pertechnetate*
I-131*
Tl-201
Ga-67
In-111
Common NM Studies By J. Sriprapaporn
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
Common NM Studies By J. Sriprapaporn
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
Common NM Studies By J. Sriprapaporn
SPECT
CT
Fused
SPECT
CT
Fused
Pheochromocytoma of right adrenal gland
Stress fracture at left tibia
Common NM Studies By J. Sriprapaporn
PET:Metabolic imaging
Using positron-emitting
radionuclides
Biological tracers (C, N, O, F)
More sensitive
Better images
Whole body evaluation
Common NM Studies By J. Sriprapaporn
Introduction to Nuclear Medicine
Bone scan and BMD Testing
GI bleeding studies
Hepatobiliary imaging
Cardiac Imaging
Common NM Studies By J. Sriprapaporn
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
Common NM Studies By J. Sriprapaporn
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
Common NM Studies By J. Sriprapaporn
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.
Common NM Studies By J. Sriprapaporn
Prostate
Lung
Breast
Neuroblastoma
Tumors commonly metastasize to bone
Common NM Studies By J. Sriprapaporn
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 !
Common NM Studies By J. Sriprapaporn
Bone Scan
ANT POST ANT POST
Common NM Studies By J. Sriprapaporn
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
Common NM Studies By J. Sriprapaporn
Cold metastatic lesions
(arrows) in a patient with
renal cell carcinoma of the
right kidney which was surgically removed
Cold Metastatic Lesions
Common NM Studies By J. Sriprapaporn
Normal PED images Rib Fractures Rib Metas. AVN s/p ERT
Bone Scan Images
Common NM Studies By J. Sriprapaporn
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
Common NM Studies By J. Sriprapaporn
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
Common NM Studies By J. Sriprapaporn
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
Common NM Studies By J. Sriprapaporn
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
Common NM Studies By J. Sriprapaporn
Introduction to Nuclear Medicine
Bone scan
GI bleeding studies
Hepatobiliary imaging
Cardiac Imaging
Common NM Studies By J. Sriprapaporn
Instrument: Dual X-ray absorptio-
metry (DXA)
Aims:
To diagnose osteoporosis (OP)
To predict fracture risk
To monitor therapy for OP
Common NM Studies By J. Sriprapaporn
Bone Mineral Density Testing
Lumbar spine Femur (Hip) Forearm
(L1-L4) (Femoral neck, total femur) (33% Radius)
Skeletal Sites to be Measured
Common NM Studies By J. Sriprapaporn
DXA: Patient Positioing
2012 Ramos
Lumbar Spine Femur-Hip
Forearm
Common NM Studies By J. Sriprapaporn
Bold = New
Common NM Studies By J. Sriprapaporn
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.
Common NM Studies By J. Sriprapaporn
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
Common NM Studies By J. Sriprapaporn
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
Introduction to Nuclear Medicine
Bone scan and BMD Testing
GI bleeding studies
Hepatobiliary imaging
Cardiac Imaging
Common NM Studies By J. Sriprapaporn
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)
Common NM Studies By J. Sriprapaporn
GI Bleeding at hepatic flexure of colon
Bleeding pattern:
• Central abdomen Small bowel
• Peripheral abdomen Large bowel
Common NM Studies By J. Sriprapaporn
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
Common NM Studies By J. Sriprapaporn
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
Common NM Studies By J. Sriprapaporn
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
Common NM Studies By J. Sriprapaporn
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
Common NM Studies By J. Sriprapaporn
Meckel’s Diverticulum
Bladder
Stomach
M
Stomach
U. Bladder
Common NM Studies By J. Sriprapaporn
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.
Common NM Studies By J. Sriprapaporn
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.
Common NM Studies By J. Sriprapaporn
Introduction to Nuclear Medicine
Bone scan
GI bleeding studies
Hepato-biliary imaging
Cardiac Imaging
Common NM Studies By J. Sriprapaporn
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)
Common NM Studies By J. Sriprapaporn
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
Common NM Studies By J. Sriprapaporn
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
Common NM Studies By J. Sriprapaporn
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
Common NM Studies By J. Sriprapaporn
Introduction to Nuclear Medicine
Bone scan
GI bleeding studies
Hepato-biliary imaging
Cardiac Imaging
Common NM Studies By J. Sriprapaporn
Radionuclide angiocardiography
Equilibrium gated blood pool
study (GBP) or Multiple Gated Analysis (MUGA study)
Myocardial perfusion imaging**
Cardiac Imaging
Common NM Studies By J. Sriprapaporn
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
Common NM Studies By J. Sriprapaporn
Common NM Studies By J. Sriprapaporn
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
Common NM Studies By J. Sriprapaporn
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
Common NM Studies By J. Sriprapaporn
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
Common NM Studies By J. Sriprapaporn
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
Common NM Studies By J. Sriprapaporn
MPI with Exercise Stress Test
Common NM Studies By J. Sriprapaporn
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
Common NM Studies By J. Sriprapaporn
Planes & SPECT Images
Long Horizontal Axis
Long Vertical Axis
Short Axis
Common NM Studies By J. Sriprapaporn
Normal Tc-99m MIBI MPI [Display Images & Walls]
STRESS
REST
STRESS
REST
Short Axis
Long Horizontal Axis
Septum Lateral
Apex Anterior
Posterior
Apex
Common NM Studies By J. Sriprapaporn
Normal Myocardial Perfusion Scintigraphy
Polar Map (Bull’s Eye)
Common NM Studies By J. Sriprapaporn
Fixed Defects: Apical & Septal Wall MI
Apical Infarct
Stress
Rest
Common NM Studies By J. Sriprapaporn
Reversible Defect: lnferior Wall Ischemia
Stress
Rest
Common NM Studies By J. Sriprapaporn
ECG-Gated Cardiac SPECT Anatomy & Function (wall motion & LVEF)
Common NM Studies By J. Sriprapaporn
Gated Cardiac SPECT
Myocardial perfusion
LV mass/volume
ES/ED volume
Ejection fraction (EF)
Wall motion
Common NM Studies By J. Sriprapaporn
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
Common NM Studies By J. Sriprapaporn
SUMMARY
Introduction to Nuclear Medicine
• Principle
• Advantages & Disadvantages
Bone scan
GI bleeding studies
• RBC scan
• Meckel’s diverticulum
Hepatobiliary scintigraphy
Cardiac imaging
Common NM Studies By J. Sriprapaporn