Emerging Myocardial SPECT with ²⁰¹Tl Using Semiconductor Detectors

Clinical Application to Stress Myocardial Perfusion Scintigraphy

Abstract

Novel single photon emission computed tomography (D-SPECT) scanners with solid-state semiconductor detectors using cadmium zinc-telluride (CZT) have been clinically applied. D-SPECT is a second scanner in Japan in which CZT detectors offer higher sensitivity and better spatial resolution than conventional Anger cameras. Myocardial counts are important to assure image quality that might be improved due to the favorable physical performance of the CZT detectors. Different physical properties between CZT detectors and Anger cameras alter the quality of myocardial SPECT images. The image quality of ²⁰¹Tl-SPECT improved after introducing CZT detectors to achieve that of ^99mTc. In addition, results from ECG-gated myocardial SPECT in clinical practice such as left ventricular volumes and ejection fraction were similar. These results could be applied to patients in the same way as those of conventional Anger cameras. However, reverse redistribution appears myocardial ²⁰¹Tl-SPECT images of apparently normal persons. Uptake in apical areas is sometimes reduced. In conclusion, myocardial perfusion scintigraphy with ²⁰¹Tl and CZT detectors has been clinically applied in Japan. Some ²⁰¹Tl data from gamma cameras and CZT detectors are identical, but others differ. Further investigation is needed to optimize myocardial perfusion scintigraphy with ²⁰¹Tl.