Improving resolution, sensitivity and applications for the NanoSPECT/CT: A high-performance SPECT/CT imager for small-animal research

Abstract

1810 Objectives: Nuclear image quality is dictated by the resolution and sensitivity capabilities of the imaging system, the dimensions of the field of view (FOV) and the physical properties of the relevant isotope. We have developed the NanoSPECT/CT; a four-headed, multi-pinhole SPECT imaging system designed for high-resolution, high-sensitivity small-animal imaging. In this work, we present results using a series of dedicated multi-pinhole apertures we have developed for the system along with a description of their resolution, sensitivity and quantification capabilities. Methods: The NanoSPECT consists of four detectors (230×215mm NaI, 33 PMTs, 2mm intrinsic resolution at 140keV) mounted along with a micro-CT on a high-precision gantry with helical scanning capabilities across both modalities (axial range 20 to 270mm). We have developed an array of interchangeable multi-pinhole apertures ranging from focused, high-resolution mouse-brain imaging to whole-body rat imaging. The increased number of apertures has been in response to user requests over time. Results: We will present a detailed description of the NanoSPECT along with numerous phantom studies and small-animal scans performed with an array of tracers. The results will address resolution, sensitivity, imaging times, injected dose and quantification results as well as multi-isotope and dynamic SPECT capabilities. Attached is a table describing the performance of the various apertures we have designed and tested with the system. Conclusions: We have developed a system with high resolution (submillimeter), high sensitivity (> 4000cps/MBq) and fast acquisition times (down to 30 seconds) with quantification (~3% precision) and dynamic scanning capabilities.