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Cardiac PET Current clinical cardiac PET can evaluate coronary artery perfusion (at rest and/or at stress), such as to risk stratify a patient for critical coronary stenosis. It can also be used to evaluate for myocardial viability, that is, distinguish infarcted from hibernating but viable tissue. Coronary perfusion is most commonly evaluated by PET with Rb-82, and viability with FDG, although other radiotracers can be used for either exam. You will note that both applications—perfusion and viability—can be accomplished with conventional nuclear treadmill SPECT (with Thallium and the Tc-99m tracers sestimibi or tetrofosmin). There are not nearly as many studies evaluating cardiac PET versus other modalities as there is for whole body oncologic PET. However, the existing data supports some increased accuracy of PET over SPECT, particularly for heavier patients, where breast, chest wall, and diaphragmatic attenuation interfere with conventional SPECT. The main advantage of PET in this scenario is its ability to correct for attenuation artifacts. However, the latest generation of SPECT cameras also has this capability. Cardiac PET studies, both perfusion and viability are, in general, approved for CMS (Medicare) and private insurance reimbursement. We currently do not offer cardiac PET as a service, but we are in the process of starting cardiac perfusion PET. This is a complicated endeavor for a number of reasons, including the paucity of adequate software and hardware, and limited availability of the Rb-82 radiotracer itself. Nevertheless we are hopeful that in the future we will be providing one of the very first clinical cardiac PET programs in our region. |
