Limited-View X-Ray Tomography Combining Attenuation and Compton Scatter Data: Approach and Experimental Results

• Main Authors: Abdulla Desmal, Jeffrey R. Schubert, Jeffrey Denker, Sherman J. Kisner, Hamideh Rezaee, Aaron Couture, Eric L. Miller, Brian H. Tracey
• Format: Article
• Language: English
• Published: IEEE 2019-01-01
• Series: IEEE Access
• Subjects: Inverse problems; computed tomography; reconstruction algorithms; x-rays
• Online Access: https://ieeexplore.ieee.org/document/8896975/

X-ray inspection systems are critical in medical, non-destructive testing, and security applications, with systems typically measuring attenuation along straight-line paths connecting sources and detectors. Computed tomography (CT) systems can provide higher-quality images than single- or dual-view systems, but the need to measure many projections leads to greater system cost and complexity. Typically, off-angle Compton scattered photons are treated as noise during tomographic inversion. We seek to maximize the image quality of limited-view systems by combining attenuation data with measurements of Compton-scattered photons, exploiting the fact that the broken-ray paths followed by scattered photons provide additional geometric sampling of the scene. We describe a single-scatter forward model for Compton-scatter data measured with energy-resolving detectors, and demonstrate a reconstruction algorithm for density that combines both attenuation and scatter measurements. The experimental results suggest that including Compton-scattered data in the reconstruction process can improve image quality for density reconstruction using limited-view systems.