Hybrid SPECT-CT and PET-CT: Current Concepts and Developments

Cardiac hybrid imaging combines different modalities in order to obtain complementary anatomical and functional information in a single imaging study. Coronary CT angiography (CTA) and myocardial perfusion imaging with single photon emission computed tomography (SPECT) or positron emission tomography (PET) are established noninvasive modalities for the diagnosis of coronary artery disease (CAD). Hybrid SPECT-CT or PET-CT is a promising tool for evaluation of CAD since it allows visualization of coronary atherosclerotic lesions and their consequences on myocardial blood flow in a single study. This appears to offer superior diagnostic accuracy for the detection of flow-limiting stenosis in patients with intermediate risk for CAD as compared with stand-alone imaging, especially by improving the positive predictive value. This article will review the concepts and currently available clinical experiences from cardiac hybrid imaging as well as discuss potential future applications.