Advances in preclinical SPECT instrumentation

Abstract

Preclinical SPECT of rodents is both in demand and very demanding. The need for high spatial resolution in combination with good sensitivity has given rise to considerable innovation in the areas of detectors, collimation, acquisition geometry, and image reconstruction. Some of the developments described herein are beginning to carry over into clinical imaging as well.

Figure 1

In synthetic-collimator imaging, multi-pinhole projection data is acquired at multiple magnifications, with the amount of multiplexing varying with the magnification.

Figure 2

(A) Photograph of a silicon double-sided strip detector in which the high-density readout electronics for one side can be seen on the left. (B) Shadow image of a radiography line-pair phantom placed in front of a silicon detector and illuminated with an Iodine-125 source. Photographs of (C) a germanium double-sided strip detector and (D) the entire detector system including readout electronics and mechanical cooling system.

Figure 3

Germanium pulse-height spectrum when simultaneously exposed to Cobalt-57 (122 keV and 136 keV), Technetium-99m (140 keV), Iodine-123 (159 keV), and Indium-111 (171 keV and 245 keV).