Po‐Thur Eve General‐17: Design and Characterization of a CT Scanner for Small Animal Imaging

A prototype cone beam computed tomography scanner has been designed for use in small animal imaging. The system consists of a small air‐cooled microfocus x‐ray source, a flat‐panel CMOS (complimentary metal‐oxide semiconductor) x‐ray detector, a motorized rotation stage and a personal computer. The scanner will ultimately be integrated into a planned quantitative optical molecular imaging system. Some initial performance characterization of the x‐ray detector has been performed. The detector response curve was found to be non‐linear at both low and high exposures. The response curve was “linearized” by using a polynomial gain correction technique involving fitting the response of the detector with a 3 rd order polynomial function. The MTF of the detector was also measured using the angled edge technique. The MTF had a value of approximately 8.6 cycles/mm at 10% contrast. A transaxial slice of an acrylic phantom reconstructed using a Feldkamp back‐projection algorithm is also presented.