Myocardial perfusion PET/CT to evaluate known and suspected coronary artery disease.

There is an extensive literature validating the use of positron emission tomography (PET) for the evaluation of regional myocardial perfusion. With PET perfusion imaging, the reported average sensitivity for detecting angiographic stenosis of >50% is 91% (range 83-100%) and the specificity is 89% (range 73-100%). While a sensitive approach for diagnosing obstructive coronary artery disease (CAD), PET (like single photon emission computed tomography) also underestimates the extent of underlying disease. However, PET's unique ability to record changes (from baseline) in left ventricular function during peak stress, as well as quantify myocardial perfusion (in mL/min/g of tissue) and derive estimates of myocardial perfusion reserve can help mitigate this limitation. Recent data suggest that PET can also provide accurate risk prediction in patients with known or suspected CAD, and that this information is additive to clinical risk prediction models. The integration of computed tomography (CT) in hybrid PET/CT scanners offers not only accurate and efficient attenuation correction, but also the possibility of providing diagnostic and prognostic information with the addition of coronary artery calcium scoring and CT coronary angiography. The combination of short lived PET radiopharmaceuticals (e.g., Rubidium-82 and N-13 ammonia) with new technology for the acquisition of the CT imaging data (e.g., prospective gating) allow a comprehensive examination of anatomy and function at a relatively low radiation dose.