2018/05/29 by Steven Tilley, Alejandro Sisniega, Tilley, Steven +5
Engineering · Medicine · #Advanced X-ray and CT Imaging #FOS: Physical sciences #Medical Imaging Techniques and Applications #Medical Physics (physics.med-ph) #Radiation Dose and Imaging
paper · pdf · doi:10.48550/arxiv.1805.11631
openalex publication_date 2018/05/29 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Detector lag and gantry motion during x-ray exposure and integration both\nresult in azimuthal blurring in CT reconstructions. These effects can degrade\nimage quality both for high-resolution features as well as low-contrast\ndetails. In this work we consider a forward model for model-based iterative\nreconstruction (MBIR) that is sufficiently general to accommodate both of these\nphysical effects. We integrate this forward model in a penalized, weighted,\nnonlinear least-square style objective function for joint reconstruction and\ncorrection of these blur effects. We show that modeling detector lag can\nreduce/remove the characteristic lag artifacts in head imaging in both a\nsimulation study and physical experiments. Similarly, we show that azimuthal\nblur ordinarily introduced by gantry motion can be mitigated with proper\nreconstruction models. In particular, we find the largest image quality\nimprovement at the periphery of the field-of-view where gantry motion artifacts\nare most pronounced. These experiments illustrate the generality of the\nunderlying forward model, suggesting the potential application in modeling a\nnumber of physical effects that are traditionally ignored or mitigated through\npre-corrections to measurement data.\n