Review ArticleRecent advances in cardiac PET and PET/CT myocardial perfusion imaging
Section snippets
Single-Photon-Computed Tomographic Imaging: Strengths and Weaknesses
Single-photon-computed tomographic imaging (SPECT) has been successfully performed for over 30 years. Over 6 million studies are performed annually with a rich literature confirming both diagnostic and accuracy prognostic value. Over these years, considerable advancement has been made in the technology to improve image quality and shorten acquisition protocols. Its strengths are many including standardized protocols, ease of use, availability, and established guidelines (Table 1).
Despite these
Cardiac PET Perfusion Imaging as an Alternative to SPECT
An alternative to SPECT imaging is cardiac PET perfusion imaging. PET offers many advantages (Table 3). These advantages include higher spatial and contrast resolution, resulting in higher image quality and improved diagnostic accuracy. Attenuation correction, a technique validated with SPECT but infrequently used, is performed on every PET perfusion study. Excellent data are emerging with regards to risk stratification with PET perfusion. With Rb-82 as the radiotracer, the procedure is rapid
Improved Image Quality
The higher energy level of PET radiopharmaceutical activity (511 vs 140 keV for technetium) provides markedly improved image quality due to higher spatial resolution, less scatter, and common use of attenuation correction. These factors improve image quality and markedly reduce attenuation artifact. Image quality was recently studied by Yoshinaga et al2 in which patients with equivocal SPECT studies were referred for cardiac PET imaging. In very high percentage of patients, the PET study
Additional Information Obtained by PET or PET/CT
Other advantages of PET imaging include the ability to measure myocardial blood flow as well as, with PET/CT cameras, both calcium scoring and coronary computerized tomographic angiography. The combination of PET and computerized tomographic imaging provides some potential advantages and synergisms with PET perfusion imaging. However measurement of coronary blood flow can be useful to diagnose not only coronary macrovascular disease, but also coronary microvascular dysfunction.11 Quantitative
Patient Selection
The optimal patient selection for PET versus SPECT imaging is emerging. There are no guidelines to indicate which patients are best suited for one testing procedure over the other, although the reasons for performing a PET study should follow previously published ACC/ASNC Guidelines and Appropriateness Criteria for Nuclear Cardiac Imaging. Patient selection is obviously dependent also upon successful pre-approval for the study by the local carriers. Currently there are several groups of
Limitations
There are some patients who are not ideal candidates for cardiac PET perfusion imaging. Patients who are claustrophobic lead the list. Offices making appointments for cardiac PET should query the patient with regards to claustrophobia. In some cases, medical therapy is successful and in others not. Very obese patients for bariatric surgery may not be ideal candidates due to bore size of the camera as well as weight limitations for the some PET imaging tables. An important aspect is payment,
Conclusion
Cardiac PET perfusion imaging with either dedicated PET or PET/CT cameras is growing in acceptance and use in the nuclear cardiology community. Available tracers provide rapid and accurate information from PET myocardial perfusion imaging studies. In addition, there are several new PET imaging tracers that will further improve the options, especially with regards to F-18 as a myocardial perfusion imaging agent.18 The data supporting PET perfusion are expanding and is demonstrating its strengths
Acknowledgments
The American Society of Nuclear Cardiology (ASNC) received a grant from the North American Center for Continuing Medical Education (NACCME) toward the cost of publishing this review. The authors received honoraria for their participation and Bracco, Inc. provided funding to NACCME for the symposium.
References (18)
- et al.
Advances in technical aspects of myocardial perfusion SPECT imaging
J Nucl Cardiol
(2009) - et al.
What is the prognostic value of myocardial perfusion imaging using rubidium-82 positron emission tomography?
J Am Coll Cardiol
(2006) - 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) - et al.
Diagnostic performance of positron emission tomography in the detection of coronary artery disease: A meta-analysis
Acad Radiol
(2008) - et al.
Diagnostic accuracy of rubidium-82 myocardial perfusion imaging with hybrid positron emission tomography/computed tomography in the detection of coronary artery disease
J Am Coll Cardiol
(2007) - et al.
Incremental value of rubidium-82 positron emission tomography for prognostic assessment of known or suspected coronary artery disease
Am J Cardiol
(1997) - et al.
Independent and incremental prognostic value of left ventricular ejection fraction determined by stress gated rubidium 82 PET imaging in patients with known or suspected coronary artery disease
J Nucl Cardiol
(2008) - et al.
Noninvasive characterization of myocardial molecular interventions by integrated positron emission tomography and computed tomography
J Am Coll Cardiol
(2006) Nuclear cardiology needs new “blood”
J Nucl Cardiol
(2009)
Cited by (0)
The review includes a summary of presentations made by the authors at a symposium sponsored by the same organization at the Annual Scientific Sessions of ASNC in San Diego, September 10-14, 2007 as well as recent advancements in the literature.