Framework to Optimize Fixed-Length Micro-Ct Systems for Propagation-Based Phase-Contrast Imaging.

A laboratory X-ray imaging system with a setup that closely resembles commercial micro -CT systems with a fixed source -to -detector distance of similar to 90 cm is investigated for single distance propagation -based phase -contrast imaging and computed tomography (CT). The system had a constant source -to -detector distance, and the sample positions were optimized. Initially, a PTFE wire was imaged, both in 2D and 3D, to characterize fringe contrast and spatial resolution for different X-ray source settings and source -to -sample distances. The results were compared to calculated values based on theoretical models and to simulated (wave -optics based) results, with good agreement being found. The optimization of the imaging system is discussed. CT scans of two biological samples, a tissue -engineered esophageal scaffold and a rat heart, were then acquired at the optimum parameters, demonstrating that significant image quality improvements can be obtained with widely available components placed inside fixed -length cabinets through proper optimization of propagation -based phase -contrast.