A SART algorithm for area integral model in desktop micro-CT system

Due to the finite size of detector unit, the area integral model (AIM) is closer to reality than the line integral model (LIM) when X-ray beams passing through a sample cast to CCD. A simultaneous algebraic reconstruction technique (SART) algorithm for AIM is proposed for improved image quality. First, a cone-beam to parallel-beam rearranged step was performed to simplify the model computation. Then, a judgement formula was used to quickly find the cells to be traversed by a strip-shaped X-ray beam and an effective method was presented to calculate intersection region. Via the comparison, both simulation and experiment show that this area-based SART has better reconstruction quality than traditional line-based SART. The algorithm is demonstrated the ability to micro-CT reconstruction. This AIM approach could be adapted for other iterative algorithms in fan-beam or small cone- angle beam CT geometry.