Gated SPECT imaging

Gated SPECT imaging has allowed the simultaneous assessment of both perfusion and function through one study. The popularity of this is amply shown by the unprecedented growth of this imaging modality throughout the country. In addition to the benefits that ventricular function adds to perfusion, gated SPECT imaging also adds to the specificity of perfusion imaging. With recent studies showing the benefit of medical therapy to interventional approaches for the treatment of patients with angina, in particular, patients with chronic stable angina, there has been an increased dependence on noninvasive imaging to assess their ischemic burden. Perfusion, with technetium-99m sestamibi SPECT imaging together with gated SPECT imaging has been the modality of choice in the majority of cases because of the ease of performance of these studies and the increased information provided. This has in large part been attributable to the ability of gated SPECT imaging to provide functional data, significantly increasing the use of radionuclide perfusion imaging. This article reviews the method of acquisition, validation, clinical use, and the newer advances of gated SPECT imaging. It gives an appreciation of the benefit that gated SPECT imaging has added in terms of risk stratification and prognosis in many cardiac patients. Under the more recent uses are myocardial viability and the increased utility of gating in this scenario, ischemic versus nonischemic cardiomyopathies, and the quandary that this testing poses to physicians and the dilemma of gated thallium imaging with its inferior image quality.