Abstract: Cadmium-Zinc-Telluride(CZT) SPECT and IQ·SPECT are new technologies used in myocardial perfusion imaging and are important in the development of nuclear cardiology. These technologies exhibit higher sensitivity and spatial resolution, shorter acquisition time, and lower injection and radiation doses than conventional SPECT. In contrast to the conventional SPECT system equipped with standard low-energy high-resolution collimators, IQ·SPECT adopts SMART-ROOM collimators and cardiac-centric acquisition to improve detection sensitivity. The detectors of CZT SPECT consist of semiconductor materials, instead of conventional sodium iodide(NaI) crystals, to improve energy resolution, spatial resolution, sensitivity, and signal-to-noise ratio. These detectors can also quantitatively analyze myocardial flow reserve. This paper reviews the imaging principle, performance parameters, and clinical application of three SPECT systems.