Authors: Reza Garzan, James Westcott, Meir Lichtenstein, Dinesh Sivartnam
Myocardial perfusion single photon emission computed tomography (SPECT) has become one of the most commonly used tests for evaluation of Coronary Artery Disease (CAD), providing both left ventricular (LV) perfusion assessment and prognostically important LV ejection fraction (LVEF) and volume values through R wave gating [1,2]. This integrated approach combining analysis of perfusion and function has already proven to be useful in tissue characterization and prognosis prediction . Standard dual-detector SPECT cameras are used in most nuclear cardiology laboratories. These cameras use sodium iodide (NaI) detectors with parallel hole collimators and the diagnostic quality of myocardial perfusion SPECT images is limited by photon sensitivity, prolonged imaging times and artifacts enhanced by a moving detector system. In an effort to overcome the limitations of these cameras, a novel dedicated ultra-fast, solid-state cardiac camera based on Cadmium Zinc Telluride has been developed. This camera provides a 3- to 5-fold increase in photon sensitivity (depending on heart size and background activity), a 1.65-fold improvement in energy resolution, and a 1.7- to 2.5-fold improvement in spatial resolution when compared to conventional NaI –based gamma cameras, which consequently allow for dramatic reduction in the total radiation dose. This new generation of cameras has become increasingly available in the past few years. There has been limited data on the agreement of the LVEF obtained during Tc-99m sestamibi myocardial perfusion study derived on this new camera with the conventional NaI-based gamma camera. We aimed to compare the resting Left Ventricular Ejection Fraction obtained during the resting phase of Tc-99m Sestamibi myocardial perfusion study on this camera with the NaI-based conventional gamma camera, using three different commercially available software packages.
Keywords: Left Ventricular Ejection Fraction, Cadmium Zinc Telluried (CZT) Camera, Mycordial Perfusion Study