Image reconstruction for interrupted-beam X-ray CT on diagnostic clinical scanners.

Image reconstruction for interrupted-beam X-ray CT on diagnostic clinical scanners.
Phys Med Biol. 2019 Jul 01;:
Authors: Muckley MJ, Chen B, Vahle T, O'Donnell T, Knoll F, Sodickson A, Sodickson D, Otazo R
Abstract
Low-dose X-ray CT is a major research area with high clinical impact. Compressed sensing using view-based sparse sampling and sparsity-promoting regularization has shown promise in simulations, but these methods can be difficult to implement on diagnostic clinical CT scanners since the X-ray beam cannot be switched on and off rapidly enough. An alternative to view-based sparse sampling is interrupted-beam sparse sampling. SparseCT is a recently-proposed interrupted-beam scheme that achieves sparse sampling by blocking a portion of the beam using a multislit collimator. The use of a multislit collimator necessitates a number of modifications to the standard compressed sensing reconstruction pipeline. In particular, we find that SparseCT reconstruction is feasible within a model-based image reconstruction framework that incorporates data fidelity weighting to consider penumbra effects and source jittering to consider the effect of partial source obstruction. Here, we present these modifications and demonstrate their application in simulations and real-world prototype scans. In simulations compared to conventional low-dose acquisitions, SparseCT is able to achieve smaller normalized root-mean square differences than tube-cur...

Source: Physics in Medicine and Biology - June 30, 2019 Category: Physics Authors: Muckley MJ, Chen B, Vahle T, O'Donnell T, Knoll F, Sodickson A, Sodickson D, Otazo R Tags: Phys Med Biol Source Type: research