Imaging the basic function unit of small/medium animal via diagnostic CT with an adaptor-and-holder assembly (AAHA): feasibility study

Abstract

Imaging the basic functional unit (BFU) of small/medium animal - an organ's smallest assembly of diverse cells that functions like the organ itself - is of significance in pre-clinical research. A BFU is usually a spheroid with its horizontal, transverse and vertical radii equal to ~50 μm and its dimension is virtually the same in small/medium animal and human. Apparently, state-of-the-art diagnostic CT scanners can't image the BFU of small/medium animal directly because of its insufficient spatial resolution. Micro-CT is of sufficient spatial resolution, but its contrast, temporal and spectral resolutions are inferior to its counterparts of diagnostic CT. We propose to image the basic function unit of small/medium animal using diagnostic CT with an adaptor-and-holder assembly (AAHA). In data acquisition, the adaptor rotates in phase with x-ray source, but the animal holder spins at an angular velocity that is opposite to the direction of adaptor rotation. Consequently, the pose of the animal remains unchanged in data acquisition, which can reduce animal's visceral motion substantially. With such an AAHA device, the spatial resolution can be increased more than 2.5 times, while the temporal resolution can potentially be increased 2 times if super-short scan is exercised. In practice, the AAHA device may not align perfectly and rotate rigorously in phase with x-ray source. Hence, motioncompensated reconstruction is needed. With a preliminary evaluation conducted in the feasibility study, it is believed that, a diagnostic CT with the AAHA device may enable imaging small/medium animal at superior spatiotemporal and contrast resolution in comparison to micro-CT.