Design and Performance of a New SPECT Detector for Multimodality Small Animal Imaging Platforms

A new detector for single photon emission computed tomography (SPECT) has been developed for the Siemens microCAT
^reg
II and Inveon Multimodality preclinical imaging systems. The detector provides an active imaging area of 15 cm times 15 cm. We review the design of this new SPECT detector and present some key performance characteristics. Integral and differential uniformity were 3.7% and 3.0%, respectively. Mean energy resolution for
^99m
Tc (140 keV) was 12.5%. Sensitivity as high as 1400 cps/MBq was measured for
^99m
Tc on a dual-detector system, and a spatial resolution of 0.7 mm (FWHM) was obtained using 0.5 mm single pinhole collimators. Additionally, we present data from representative preclinical SPECT studies acquired with single and multi-pinhole collimators and multiple isotopes. Reconstructed images demonstrate that this detector is capable of high-resolution SPECT for multimodality small animal imaging.