PET vs. SPECT: An MPI Case Review - medical imaging PET MPI: Prognosis 7. Dorbala et al. J Am Coll...
Transcript of 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
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service to the profession and are believed to be reliable based
on current scientific literature. The materials are for educational
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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
1. Bateman, et. al. J Nucl Cardiol 2006 Jan-Feb; 13(1):24-33
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
1. Bateman, et. al. J Nucl Cardiol 2006 Jan-Feb; 13(1):24-33
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
1. Bateman, et. al. J Nucl Cardiol 2006 Jan-Feb; 13(1):24-33
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
Demographics: 59-year-old female
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
Case #2: SPECT Images
Case #2: Rb-82 PET Images
Case #2: SPECT and PET Images
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)
Clinical Response Non-ischemic Non-ischemic
BP Response Normal Normal
ECG Response Negative* Negative*
Radiopharmaceutical Tc-99m sestamibi Rubidium-82
Rest / Stress Dose 12mCi / 30mCi 36mCi / 36mCi
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 #3: SPECT Images
Case courtesy of Jim O’Donnell, MD, University Hospitals Health System, Cleveland, OH
Case #3: Rb-82 PET Images
Case #3: SPECT and PET Images
Tc-99m Rb-82
Case #3: Summary
Protocol SPECT PET
Mode of Stress Dipyridamole Dipyridamole
Clinical Response Non-ischemic Non-ischemic
BP Response Normal Normal
ECG Response Negative Negative
Radiopharmaceutical Tc-99m sestamibi Rubidium-82
Rest / Stress Dose 10mCi / 33mCi 47mCi / 47mCi
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
Demographics: 69-year-old female
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.
Case #4: Rb-82 PET Images
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
Additional References
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
Additional References
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.