pet vs. spect: an mpi case review - medical imaging pet mpi: prognosis 7. dorbala et al. j am coll...

“Cardiac PET MPI is a well-established and highly accurate technique for

detecting hemodynamically significant CAD. The ability to reduce attenuation

artifact is useful in all patients, but particularly the obese.” 7

PET vs. SPECT: An MPI Case Review

7. ASNC Model Coverage Policy: Cardiac positron emission

tomographic imaging. J Nucl Cardiol 2013; 20:916-47

These materials were prepared in good faith by MITA as a

service to the profession and are believed to be reliable based

on current scientific literature. The materials are for educational

purposes only and do not replace either the need for

individualized patient diagnosis and treatment planning by

qualified physicians based on existing good practices or the

need for implementation by qualified radiologists or other

qualified healthcare practitioners. Neither MITA nor its members

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MITA does not endorse the proprietary products or processes of

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Legal Disclaimers

Purpose

Present published data comparing the image quality and

diagnostic accuracy of PET MPI to SPECT MPI in

similarly matched patient types

Report on Rb-82 PET MPI event-free survival and

prognosis

Demonstrate, through patient case studies, the effect of

better image quality in the treatment of patients

Gender bias

BMI

Multi-vessel disease (MVD)

Image Quality:

PET MPI vs. SPECT MPI

Figure 1. Image quality scores for PET and SPECT perfusion and ECG-gated scans

1. Bateman, et. al. J Nucl Cardiol 2006 Jan-Feb; 13(1):24-33

Why is the Image Quality with PET

better than SPECT?

Improved image quality for PET vs. SPECT due to:1-3,6

Higher count rates (240% increase over SPECT)

Improved spatial resolution; 3mm PET vs. 6mm SPECT

Routine and robust attenuation correction on all scans

Better detection of MVD


2. Merhige, et al. J Nucl Med 2007; 48:1069–1076

3. Yoshinaga, et al. J Amer Coll Cardiol 2006; 48(5):1029-1039

4. Chow, et al. J Nucl Med 2005; 46:1095–101

6. Dorbala et al. J Nucl Med 2007; 48(3):349-358

Diagnostic Accuracy:

PET vs. SPECT


BY GENDER BY BMI

69%

84%

*P = 0.55

67%

88%

*P = 0.009

MEN WOMEN

70%

87%

67%

85%

*P = 0.05 *P = 0.02

BMI<30 BMI>30

MVD SENSITIVITY

48%

71%

*P = 0.03

MVD

SPECT

PET

PET MPI: Improved Interpretive

Certainty vs. SPECT MPI

Figure 2. Comparison of degrees of interpretive certainty of SPECT and PET studies


5. McArdle et al. J Am Coll Cardiol 2012; 60(18):1828-37

*P < 0.01 for Rb-82 PET vs. gated AC SPECT

PET:

Pooled Sensitivity = 90%

Pooled Specificity = 88%

Rb-82 PET vs. Gated AC Tc-99m

SPECT

Rb-82 PET SROC Tc-99m SPECT SROC

AUC: 0.909

Q (): 0.841

SPECT:

Pooled Sensitivity = 85%

Pooled Specificity = 85%

AUC: 0.95

Q (): 0.8907

*

6. Dorbala et al. J Nucl Med 2007; 48(3):349-358

P <

0.0001 P <

0.0001

P = 0.003

Left Ventricular EF Reserve and

Magnitude of Jeopardized Myocardium

3. Yoshinaga K, et al. J Am Coll Cardiol 2006; 48:1029-39

Follow up (years)

Log-rank p=0.001

Mild

Normal

Moderate - Severe

0.70

0.75

0.80

0.85

0.90

0.95

1.00

0 0.5 1 1.5 2 2.5 3 3.5 4

Rb-82 PET MPI: Event-Free Survival

Summed Stress Score, Total Cardiac Events

Prognostic Value of Stress Myocardial Perfusion Positron Emission Tomography:

Results from a Multicenter Observational Registry

All-cause death (N = 7,061) Cardiac death (N = 6,037)

Rb-82 PET MPI: Prognosis

7. Dorbala et al. J Am Coll Cardiol 2013 Jan; 61(2):176-8

CASE STUDIES

Following are images of a patient who underwent a SPECT MPI and a PET MPI

study 2 weeks apart at Harvard/Brigham & Women’s Hospital in Boston, MA.

The case and study all images courtesy of Marcelo DiCarli, MD

(Harvard/Brigham & Women’s Hospital).

Case #1

Patient Profile

Demographics: 77-year-old female

Body Habitus: Wt: 160 lbs; Ht: 61 inches; BMI: 31

Risk Factor: Hypertension

Reason for Test: Atypical chest pain

ECG: normal sinus rhythm and nonspecific T-wave

abnormalities

Meds: atenolol, famotidine, aspirin, anticoagulant

Case #1: SPECT Images

Case #1: Rb-82 PET Images

Tc-99m Rb-82

Case #1: SPECT and PET Images

Case #1: Summary

Cardiac catheterization was not performed because the

PET MPI study was normal.

Protocol SPECT PET

Mode of Stress Adenosine (4 min) Dipyridamole (4 min)

Clinical Response Non-ischemic Non-ischemic

BP Response Normal Normal

ECG Response Negative Negative

Radiopharmaceutical Tc-99m sestamibi Rubidium-82

Rest / Stress Dose 11mCi / 33mCi 60mCi / 60mCi

Gated Yes Yes

Following are images of a patient who underwent a underwent a SPECT MPI

and a PET MPI study 12 days apart at Harvard/Brigham & Women’s Hospital in

Boston, MA. The case and all study images courtesy of Marcelo DiCarli, MD

and Sharmila Dorbala, MBBS (Harvard/Brigham & Women’s Hospital).

Case #2

Patient Profile


Body Habitus: Wt: 140 lbs, H: 65 inches, BMI: 23.5

Reason for Test: evaluation of atypical chest pain and

dyspnea

Meds: Metoprolol, amlodipine, captopril, furosemide,

aspirin, simvastatin, bupropion


Tc-99m Rb-82

Case #2: Summary

*Patient had normal sinus rhythm and non-specific ST-T wave

abnormalities on the resting ECG prior to the MPI studies

Protocol SPECT PET

Mode of Stress Adenosine (4 min) Dipyridamole (4 min)



ECG Response Negative* Negative*



Gated Yes Yes

Case #2: Report Comparison

SPECT MPI Report

There was a small defect of moderate intensity in the mid to apical

anterior wall that remained fixed on the rest images and most likely

is due to breast attenuation artifact; however a non-transmural

myocardial scar cannot be excluded.

PET MPI Report

There were no regional perfusion defects seen on the stress or rest

images. The patient’s PET/CT test results are normal and suggest

no evidence of flow-limiting CAD. The results suggest that the

previously described fixed anterior wall defect (her prior SPECT

study) is likely to represent an attenuation artifact.

Cardiac catheterization was not performed because the

PET MPI study was normal.

Following are images of a patient who underwent a SPECT MPI and a PET MPI

study 2 weeks apart at University Hospitals Case Medical Center in Cleveland, OH.

The case and all images are courtesy of Jim O’Donnell, MD (University Hospitals

Case Medical Center, Cleveland, OH).

Case #3

Patient Profile

Demographics: 82-year-old male

Body Habitus: Wt: 210 lbs; Ht: 70 inches; BMI: 30.1

Risk Factor: Hypertension

Reason for Test: preoperative cardiac evaluation prior to

hip replacement surgery

Meds: aspirin, bisoprolol

Case courtesy of Jim O’Donnell, MD, University Hospitals Health System, Cleveland, OH



Tc-99m Rb-82

Case #3: Summary

Protocol SPECT PET

Mode of Stress Dipyridamole Dipyridamole



ECG Response Negative Negative



Gated Yes Yes

Length of Time 2.5 hours 40 minutes

Case #3: Report Comparison

SPECT MPI Report

Fixed defect is noted at the apex, which does not move or thicken

appropriately and likely represents a scar. There is no SPECT

evidence of ischemia. LV ejection fraction of 40 percent (normal

above 45 percent).

PET MPI Report

The PET images demonstrate the above-described apical scar

pattern but also demonstrate a mild to moderate anterior ischemic

pattern involving the distal half of the anterior segment. This is

suggestive of mild peri-infarct ischemia. The LV ejection fraction in

the PET study is 53% at rest rising to 57% with pharmacologic

stress (normal left ventricular function). Statistically, the likelihood of

a perioperative event is still fairly low.

Even though this patient received pre-operative

clearance for hip surgery, the detection of

ischemia on the PET study provided

prognostically useful information to assist

in the management of this patient’s

progressive CAD.

Case #3: Final Note

Following are images of a patient who underwent a rest/dipyridamole stress

Rubidium-82 myocardial perfusion PET study. The case and all images are

courtesy of Tim Bateman, MD (Cardiovascular Consultants, Kansas City, MO).

Case #4

Patient Profile


Risk Factor:, Hyperlipidemia, Hypertension, Type II DM

Reason for Test: admitted to hospital after a CVA; found

to be in atrial fibrillation with small increase in troponin-I;

abnormal ECG

Meds: Coumadin, Lovenox, Toprol XL, Lipitor, Altace (over

the last 24 hrs. prior to imaging per rest/stress dipyridamole cardiogen-82

PET report)

REST

Transient Ischemic Dilation (TID) Ratio: 1.63 (normal = 1.0)

STRESS

A larger cavity size

on stress images

can indicate a

near-balanced flow

reduction.


PEAK STRESS

LVEF 50%

REST

LVEF 61%

A lower EF during

exercise vs. rest is

considered an abnormal

compensatory response

at a time of increased

demand.

Case #4: Rb-82 PET Functional

Images

Case #4: Report

The combined test findings indicate the following:

Virtually diagnostic for the presence of CAD.

Apical ischemia probably in the distribution of the left anterior

descending coronary artery.

Severe transient ventricular dilation, suggesting possible near-

balanced flow reduction in multiple coronary territories.

Normal left ventricular function at rest (LVEF 61%).

Significant drop in LVEF in response to pharmacologic stress.

Prognostically concerning scan, with numerous markers of high-risk

for major adverse coronary events.

Case #4: Catherization Correlation

The combined test findings indicate the following:

Coronary angiography showed a 75% left main stenosis,

a 90% stenosis of the mid LAD and a 70% right coronary

artery stenosis

CABG surgery was performed after recovery from the

CVA

1. Bateman TM, Heller GV, McGhie AI, et al. Diagnostic accuracy of

rest/stress ECG-gated Rb-82 myocardial perfusion PET: comparison with

ECG-gated Tc-99m sestamibi SPECT. J Nucl Cardiol 2006 Jan-Feb;

13(1):24-33

2. Merhige ME, Breeny WJ, Shelton V, et al. Impact of myocardial perfusion

imaging with PET and 82Rb on downstream invasive procedure utilization,

costs, and outcomes in coronary disease management. J Nucl Med 2007;

48:1069–1076

3. Yoshinaga K, Chow B, Williams K, et al. What is the prognostic value of

myocardial perfusion imaging using rubidium-82 positron emission

tomography? J Amer Coll Cardiol 2006; 48(5):1029-1039

4. Chow BJW, Wong JW, Yoshinaga K, et al. Prognostic significance of

dipyridamole-induced ST depression in patients with normal 82Rb PET

myocardial perfusion imaging. J Nucl Med 2005; 46:1095–101

Slide References

5. McArdle BA, Dowsley TF, deKemp RA, et al. Does rubidium-82 have

superior accuracy to SPECT perfusion imaging for the diagnosis of

obstructive coronary disease? J Am Coll Cardiol 2012; 60(18):1828-37

6. Dorbala S, Vangala D, Sampson U, et al. Value of vasodilator left

ventricular ejection fraction reserve in evaluating the magnitude of

myocardium at risk and the extent of angiographic coronary artery disease:

A 82Rb PET/CT study. J Nucl Med 2007; 48(3):349-358

7. Dorbala S, DiCarli M, Beanlands R, et al. Prognostic value of stress

myocardial perfusion positron emission tomography: Results from a

multicenter observational registry. J Am Coll Cardiol 2013; 61(2):176-184

Slide References

Additional References

Sherif Iskander and Ami Iskandrian; Risk Assessment Using Single-Photon

Emission Computed Tomographic Technetium-99m Sestamibi Imaging. J

Am Coll Cardiol. 1998;32:57-62.

Gary Heller and Robert Hendel, Editors: Handbook of Nuclear Cardiology:

Cardiac SPECT and Cardiac PET. Springer-Verlag London ©2013

Benjamin J. W. Chow et al, Prognostic Value of PET Myocardial Perfusion

Imaging in Obese Patients, JACC Cardiovascular Imaging 2014; 7(3)

Vasken Dilsizian and Jagat Narula, Atlas of Nuclear Cardiology, 3rd Edition,

©2009 Current Medicine Group LLC

Marcelo DiCarli et al, Long Term Survival of Patients with Coronary Artery

Disease and Left Ventricular Dysfunction: Implications for the Role of

Myocardial Viability Assessment in Management Decisions. J Thorac

Cardiovasc Surg 1998; 116(6):997-1004

D’Egidio G, et al. Increasing Benefit From Revascularization is Associated

With Increasing Amounts of Myocardial Hibernation; A Substudy of the

PARR-2 Trial. JACC Cardiovascular Imaging 2009; 2(9)

2013 ACCF/ACR/ASE/ASNC/SCCT/SCMR Appropriate Utilization of

Cardiovascular Imaging in Heart Failure. J Am Coll Cardiol 2013; 61(21)

Ziadi M, et al. Impaired Myocardial Flow Reserve on Rubidium-82 Positron

Emission Tomography Imaging Predicts Adverse Outcomes in Patients

Assessed for Myocardial Ischemia. J Am Coll Cardiol 2011; 58(7)

Murthy V, et al. Improved Cardiac Risk Assessment with Non-Invasive

Measures of Coronary Flow Reserve. Circulation 2011; 124(20):2215-2224


Skali H, Schulman A and Dorbala S. 18-F FDG PET/CT for the Assessment

of Myocardial Sarcoidosis. Current Cardiology Reports 2013; 15(4):352

Einstein AJ. Effects of Radiation Exposure From Cardiac Imaging: How

Good Are the Data? J Am Coll Cardiol 2012; 59(6):553-565

Cerqueira MD, et al. ASNC Information Statement: Recommendations for

reducing radiation exposure in myocardial perfusion imaging. J Nucl Cardiol

doi:10.1007/s12350-010-9244-0. Published online 26 May 2010


Important Safety Information

Image interpretation errors can occur with PET imaging. A negative image

does not rule out recurrent prostate cancer and a positive image does not

confirm its presence. Clinical correlation, which may include

histopathological evaluation, is recommended.

Hypersensitivity reactions, including anaphylaxis, may occur in patients who

receive PET radiopharmaceuticals. Emergency resuscitation equipment and

personnel should be immediately available.

PET/CT imaging contributes to a patient’s overall long-term cumulative

radiation exposure, which is associated with an increased risk of cancer.

Safe handling practices should be used to minimize radiation exposure to

the patient and healthcare providers.

Adverse reactions, although uncommon, may occur when using PET

radiopharmaceuticals. Always refer to the package insert prior to use.

pet vs. spect: an mpi case review - medical imaging pet mpi: prognosis 7. dorbala et al. j am coll...

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