Low-dose cardiac 4D cone-beam CT image reconstruction using two-cycle data

This study was conducted to demonstrate the feasibility of a new scanning method and image reconstruction for low-dose cardiac CT. We proposed a scanning method that acquires cardiac cone-beam data during two-cycles of cardiac motion. Assuming that the cardiac motion for the two cycles stays stable, we adjust the gantry rotation speed such that the cone-beam data of a given phase are sampled at orthogonal view-angles. In order to keep the dose level lower to the conventional scans, we employed an x-ray tube current modulation in this approach. Prior image constrained compressed sensing (PICCS) algorithm was used for image reconstruction. We performed a numerical study, and evaluated the result images quantitatively. The proposed method improved the accuracy of the image reconstruction for each cardiac phase.