Step-and-shoot VCT cardiac imaging

Cardiac imaging has become one of the most recent advancements in CT clinical applications. Currently, low-pitch helical is typically employed in most data acquisition protocols, which results in high radiation dose to patients. In this paper, we propose a different data acquisition protocol, the step-and-shoot mode, which potentially presents a 52-83% dose reduction. Because of the large detector coverage in z of the new scanners, the total data acquisition time is comparable to that of the helical scans, for an average heart size of 12 cm to 16 cm. In addition, the proposed acquisition has the advantage of improved robustness in handling irregular heart rates. In conjunction with the new acquisition protocol, we present a complimentary reconstruction algorithm to combat axial truncation problem encountered in cone beam half-scans. Computer simulations, phantom experiments, and animal studies were conducted to validate our approach.