Performance evaluation of an XRII-based volume CT scanner

摘要

Abstract: A laboratory quantitative CT scanner capable of producing high- resolution images in all three dimensions has been developed. The system uses an x-ray image intensifier (XRII), optically coupled to a time-delay integration (TDI) CCD to obtain low-noise, high- resolution projections from many angles around a rotating sample. The scanner operates in two modes, producing either a single, transverse image through the sample or a three-dimensional image of the sample volume, over a field-of-view (FOV) ranging from 4 to 12 cm. The performance of this quantitative CT system has been characterized with respect to accuracy, precision, and spatial resolution. The average accuracy in attenuation measurements was $POM@0.01 cm$+$MIN@1$/ (RMS). Measurement precision varied with voxel size and x-ray exposure, from $POM@0.01 cm$+$MIN@1$/ to $POM@0.03 cm$+$MIN@1$/. Limiting spatial resolution also varied with scanner FOV, ranging from 2.8 mm$+$MIN@1$/ to 1.2 mm$+$MIN@1$/ for the 4 and 12 cm FOVs, respectively. Applications of the volume CT scanner in research tasks using live animals and in vitro preparations are discussed.!28