A wide field-of-view inverse geometry CT system

Computed tomography (CT) today can image a thick volume in a few seconds using a helical source trajectory. Shorter scan times are highly desired to improve image quality degradation due to physiologic motion. Inverse-geometry CT (IGCT) is a new paradigm for CT imaging. Employing an array of x-ray sources, the detector area can be made much smaller and more efficient than in conventional CT resulting in higher dose efficiency and the capability of measuring a thick volume (e.g., the heart) in under 200 ms.; The in-plane field-of-view is a limiting factor in IGCT design due to its dependence on the size of the x-ray source array. This work first investigates a multi-eye IGCT system which incorporates three detector arrays to increase the field-of-view without requiring a larger source array. Optimal placement of the detectors is determined and a pre-patient x-ray collimator design is presented. Experiments from a table-top multi-eye IGCT system demonstrate its feasibility.; Secondly, an optimization framework is outlined to optimize IGCT design based on a cost function approach. A simulated annealing algorithm is used to minimize a weighted cost function with the weights varied to trace out Pareto-optimal curves that highlight trade-offs among field-of-view, resolution and signal-to-noise ratio. These trade-offs are compared to theoretical predictions.; Finally, a 3D reconstruction algorithm based on a modified Fourier rebinning algorithm is presented. The algorithm uses all ray measurements and is shown to be both computationally efficient and exact.