Myocardial perfusion imaging with PET.

Although SPECT has become an accepted imaging technique for myocardial perfusion studies, there are several advantages to evaluating coronary artery disease (CAD) with PET. CAD is a complex, dynamic disease and quantitative measurements of myocardial blood flow by PET can improve the functional characterization of CAD. The major advantage of PET over SPECT is its ability to provide attenuation-corrected images, which decreases incidence of attenuation artifacts and increases specificity. Myocardial perfusion imaging with PET can also provide more accurate information on localization of disease, as well as quantitative assessment, in absolute values, of myocardial blood flow. The measurement of regional flow reserve allows for physiologic characterization of stenosis severity, and may provide early detection of CAD as well as prognostic information. The disadvantage of PET, compared to SPECT, is that the equipment and operations are more expensive. As more accurate diagnostic and prognostic data lead to improved patient management, the cost-to-benefit ratios of PET and SPECT in the clinical setting need to be further analyzed to determine which diagnostic test is most efficient in the work-up of patients with suspected or known CAD.