Tomographic Reconstruction: a Radiation Reduction Approach

Computed tomography (CT) enables visualization of the internal structure of an object without cutting it open. Reducing the exposure to these rays has always been sought after in order to prevent the specimen from damage, especially if it is being imaged multiple times over an extended time duration. For this reason, one may either 1) reduce the number of directions along which rays are passed (few-view), or 2) reduce the intensity (low-dose) of rays or apply both of these. This thesis aims to reduce the artefacts of few-view and low-dose imaging by using data-driven (prior-based) techniques within the widely used Compressed Sensing (CS) framework. We specifically focus on reconstructing in longitudinal studies i.e., when repeated scans of an object are taken to study the changes within it over a period of time.