Design and Initial Experimental Evaluation of the Alpha-SPECT: A Full-Body Clinical SPECT System with High-Performance CZT Imaging Spectrometers and Micro-Rotating Dual-Aperture Collimation for Imaging Therapeutic Radionuclides

In this paper, we report the design, development, and initial experimental evaluation of the Alpha-SPECT system, a full-body clinical SPECT scanner equipped with state-of-art CZT imaging spectrometers ideally suited to simultaneous imaging of therapeutic alpha-emitters (e.g., Ac-225, Ra-223, Lu-177, etc.) and their daughters (e.g., Fr.221, At-217, Bi-213, and Po-213 from the decay of Ac-225) in patients. Besides the potential for imaging alpha-labeled radiopharmaceutical therapy (a-RPT), the Alpha-SPECT system is intended to be a general-purpose clinical SPECT scanner for a wide variety of diagnostic and therapeutic applications. The system is equipped with a dual-aperture collimator that is installed on a CT-scanner-derived rotational gantry to allow the real-time switching between the two aperture configurations, as well as micro-swing of aperture in front of the CZT detectors with a sub- 15 mm precision to provide a variable FOV of 20-50 cm diameter and facilitate super-resolution sampling for further improved imagign resolution.