Tomographic image reconstruction from continuous projections

An important design aspect in tomographic image reconstruction is the choice between a step-and-shoot protocol versus continuous X-ray tube movement for image acquisition. A step-and-shoot protocol implies a perfectly still tube during X-ray exposure, and hence involves moving the tube to its next position only in between exposures. In a continuous movement protocol, the tube is in a constant motion. The angular integration of the rays inherently produces blurred projections. Conventional reconstruction from such projections leads to blurred reconstructed images, and therefore the projection angles are kept small. Important advantages of a continuous scanning protocol are shorter acquisition times and less demands on modality construction from a mechanical point of view. In this work, the continuous protocol is extended with continuous projections, in which the X-ray source is continuously emitting X-rays over larger angles. The focal spot motion can no longer be ignored and is modeled in the reconstruction. The reconstruction quality is compared with the equivalent step-and-shoot counterpart showing improved results for region of interest tomography.