Introduction toCardiac PET Perfusion Imaging

with CardioGen-82®

(Rubidium Rb 82 Generator)

Please see full prescribing information accompanying this presentation

Objectives

• Understand advantages of cardiac PET perfusion imaging

• List commercially available cardiac PET agents• Review technical aspects of CardioGen-82®• Discuss dedicated cardiac PET and PET/CT

protocols• Review clinical case studies

Advantages of Cardiac PET Perfusion Imaging

• Improved efficiency1 • Lower radiation exposure1

• Fewer attenuation artifacts1

• Improved resolution1

1. Bateman TM. PET Myocardial Perfusion Imaging: Making the Transition to a Clinical Routine. Appl Imaging: Applications Nucl Cardiol. 2002; 3(1): 1-6

Commercially Available Cardiac PET Agents

• Perfusion Imaging– Rubidium Rb 82– N-13 Ammonia

• Viability Imaging– F-18 Fluorodeoxyglucose (FDG)

Sensitivity & Specificity2 Author Sensitivity Specificity # Patients

Gould 95% 100% 50

Demer 94% 95% 193

Go 93% 78% 202

Schelbert 97% 100% 45

Yonekura 93% 100% 49

Williams 98% 93% 146

Stewart 84% 88% 319

Weighted Avg. 93% +/- 8 92% +/- 5 766

2. Nuclear Medicine Self-Study Program III: Nuclear Medicine Cardiology. Botvinik, EH, Ed. 1998: Society of Nuclear Medicine, Reston, VA.

CardioGen-82® (Rubidium Rb 82 Generator)

• Indication:

Useful in distinguishing normal from abnormal myocardium in patients with suspected myocardial infarction.

CardioGen-82® (Rubidium Rb 82 Generator)

• Rubidium-82 (Rb-82) is produced by decay of Strontium-82 (Sr-82)

• 75 second T½ • Kinetics:

– Potassium analog– High extraction fraction at high flow rates

• Defects visualized 2-7 minutes after injection• Same sized dose at stress & rest due to short T½ • New generator every 28 days• Fixed price, not unit dose• Dose available 24 hours per day, 7 days per week• Pharmacologic stress studies

CardioGen-82® (Rubidium Rb 82 Generator)

• Generator replaced every 28 days• Rb-82 dose is provided within 10

minutes• Generator must be utilized with the

calibrated CardioGen-82® Infusion System

• Infusion System is automated for the infusion and patient dose

• Permits accurate dosing with minimal operator interface, thus decreasing radiation exposure

• Contains shielding vault for CardioGen-82® Generator and waste container

Protocols

Sample Dedicated PET Protocol

Protocol courtesy of Timothy Bateman, MDProtocol courtesy of Timothy Bateman, MDApproximately 35 minutesApproximately 35 minutes

Rest Tx Rest Tx ScanScan

Rb-82Rb-82

DipyDipy0.56 mg/kg0.56 mg/kg

Rb-82Rb-82

Approx 4 minApprox 4 minApprox 5 minApprox 5 min

Approx 4 minApprox 4 minApprox 5 minApprox 5 min

Approx 3 minApprox 3 min

EmissionEmissionScan 2DScan 2D

10 phases10 phases30 seconds30 seconds

Rb-82Rb-82

3D Gated3D Gated ScanScan

Approx 3 minApprox 3 min

3D Gated3D Gated ScanScan

EmissionEmissionScan 2DScan 2D

Stress Tx Stress Tx ScanScan

10 phases10 phases30 seconds30 seconds

Sample PET/CT Protocol

Protocol courtesy of Marcelo DiCarli, MDProtocol courtesy of Marcelo DiCarli, MDApproximately 30 minutesApproximately 30 minutes

scoutscout CT-transCT-trans

Rb-82Rb-8250-60 mCi50-60 mCi

70-90 sec70-90 sec90-120 sec90-120 sec

gatedgatedrestrest

pt outpt out

DipyDipy0.56 mg/kg0.56 mg/kg

scoutscoutCT-transCT-trans

70-90 sec70-90 sec90-120 sec90-120 sec

Rb-82Rb-8250-60 mCi50-60 mCi

gatedgatedstressstress

Approx 1 minApprox 1 min Approx 7 minApprox 7 min Approx 6 minApprox 6 min Approx 1 minApprox 1 min Approx 7 minApprox 7 min

Case Studies

Normal Rest-Stress CardioGen-82® Myocardial

Perfusion PET StudyRest/Dipyridamole Stress CardioGen-82®

Courtesy of Tim Bateman, MDMid America Heart InstituteKansas City, MO

CASE 1

HX: 60 year-old female admitted to hospital in the early morning after a 45 minute episode of central chest pain that began after smoking a cigarette.

Risks: Smoker, Hypertension

Rest ECG: T-wave flattening

Enzymes: Normal X2

PMH: GERD, Depression, Post-traumatic stress disorder

Meds: Atenolol

Reason for PET CardioGen-82® study:

• Patient was on beta blocker, pharm stress preferred

• Referring MD seeking results within 1 hour

STRESS

REST

CASE 1

TID Ratio 0.96

CASE 1

PEAK STRESS

REST

LVEF 76%

LVEF 67%

Rest/Stress Dipyridamole CardioGen-82® Myocardial Perfusion PET Report: Case 1

Clinical Response: Non-diagnostic (Dipyridamole)

ECG-Response: Non-ischemic

Scintigraphic Response: Non-ischemic

The combined test findings indicate the following:

• Low-likelihood for acute coronary syndrome

• No ischemia or regions of myocardial injury

• Normal segmental contraction and thickening

• Normal global LV function with rest LVEF 67% and peak stress LVEF 76%

Characteristics of a Normal CardioGen-82® Myocardial Perfusion PET Study

• Uniform distribution of tracer, independent of gender

• LV cavity at peak stress equal to or smaller than at rest

• Uniform and normal wall thickness and thickening

• Uniform and normal regional wall motion

• Peak stress LVEF > rest LVEF

Abnormal Rest-Stress CardioGen-82® Myocardial

Perfusion PET Study: Multivessel Abnormality

Rest/Dipyridamole Stress CardioGen-82® Myocardial Perfusion PET Study

Courtesy of Timothy Bateman, MDMid America Heart InstituteKansas City, MO

CASE 2: Abnormal (MVD)

History: 73 year-old large female (BMI 40) admitted to hospital after 2 hours of left-sided chest pain

and acute left-sided weakness and numbness

Hospital course: Neurologic symptoms resolved; troponins nl.

PMH: Stents in PDA and proximal LAD; polymyositis

ECG: Normal

Reason for PET CardioGen-82® study:

• Polymyositis and recent CVA event, pharm stress preferred

• Patient’s body habitus

CASE 2 STRESS

REST

TID Ratio 1.38

CASE 2PEAK

STRESS

REST

LVEF 58%

LVEF 68%

Rest/Stress Dipyridamole CardioGen-82® Myocardial Perfusion PET Report: Case 2

The combined test findings indicate the following:

• Moderate sized region of intense ischemia involving the entire septum, from base to apex

• Peak-stress transient myocardial stunning with loss of regional contraction and thickening

• Normal LV regional and global function at rest (LVEF 68%)

• Ventricular decompensation with stress (transient cavity enlargement and drop in LVEF to 58%)

• Results communicated verbally at time of dictation

CASE 2 (Continued)

Results

Coronary angiography showed an 80% stenosis of a posterior descending branch of the right coronary artery, and a large 1st septal perforator that was “jailed” by the LAD stent.

The PDA was stented; the septal perforator was judged to best be left alone due to concerns about compromising the LAD itself.

Characteristics of an Abnormal CardioGen-82® Myocardial Perfusion PET Study in Multiple Coronary Territories

• Decrease in regional tracer uptake at peak stress in more than one coronary artery distribution

• LV cavity at peak stress much larger than at rest

• Frequent and multiple regional contraction abnormalities (stunning) at peak stress

• Peak stress LVEF < rest LVEF

Summary

• Cardiac PET perfusion offers:– Improved efficiency1 – Lower radiation exposure1

– Fewer attenuation artifacts1 – Improved resolution1

• CardioGen-82® (Rubidium Rb 82 Generator) fits well into any cardiac PET perfusion operation

1. Bateman TM. PET Myocardial Perfusion Imaging: Making the Transition to a Clinical Routine. Appl Imaging: Applications Nucl Cardiol. 2002; 3(1): 1-6