SPECT in Ischemic Heart Diseases

Myocardial perfusion imaging (MPI) plays a major role on the diagnosis, stratification, therapy-guidance and prognosis of patients with coronary artery disease (CAD) since the middle 1900s. Within these procedures, single positron emission computed tomography (SPECT) emerged as the first method that evaluated myocardial perfusion directly, that was non-invasive, readily available, and with an adequate cost-benefit relationship. Because of that, SPECT promptly positioned as one of the gatekeeper tests for patients with myocardial ischemic symptomatology. SPECT has been widely available since the early 1980s, and its value in the management of CAD patients has been reported in multiple studies, including those with the highest quality of evidence (i.e., systematic reviews and meta-analysis). And despite the current availability of other modalities of MPI tests (i.e., positron emission tomography (PET) and cardiac magnetic resonance (CMR)), MPI SPECT continues as one of the most requested and validated imaging procedure in the evaluation of patients with suspected CAD. Moreover, the advent of modern solid-state detectors (cadmium-zinc-telluride (CZT)) devices, has shown the capacity of improving the diagnostic accuracy of SPECT and reducing acquisition time and radiation exposure. Besides, this technology promises myocardial blood flow (MBF) and myocardial flow reserve (MFR) quantifications and, when combined with gated-SPECT techniques, left ventricular function (LV-function) measurements; parameters currently only available in other MPI techniques (i.e., PET, CMR). This article presents the state of the art about MPI SPECT regarding its diagnostic applications and value, also, describes the ultimate technological advances developments for improving its value in heart diseases, and lastly, discusses the future perspectives of MPI SPECT within the field of nuclear cardiology.