The clinical value of assessing left ventricular function from gated SPECT perfusion studies

Gated myocardial perfusion SPECT is a technique that is rapidly becoming widespread in the nuclear cardiology arena, and it currently accounts for a majority of all perfusion SPECT acquisitions performed in the USA. Its main advantage is that of providing important incremental clinical information over SPECT perfusion assessment alone, at essentially no extra cost. With respect to the diagnosis of cardiac disease, gated SPECT has been demonstrated to improve specificity by helping identify attenuation artifacts in patients with suspected coronary artery disease, and is also key in identifying patients with non-ischemic cardiomyopathies. In prognostic assessment, gated SPECT-derived measurements of ejection fraction achieve substantial incremental stratification of patients at risk for cardiac death or myocardial infarction, compared to perfusion scores, and volume measurements further improve risk stratification. New quantitative algorithms allow the fast, accurate and reproducible measurement of parameters of global cardiac function (ejection fraction, end-systolic and end-diastolic volume) as well as regional cardiac function (myocardial wall motion and thickening), all of which have been validated against a wide variety of gold standards.