Project Description

We proposed “intepolated CT” techniques as a new attenuation correction (AC) method for static and gating ECT to reduce the potential respiratory misalignments artifacts. CT images of the desired phases, e.g., end-inspiration and end-expiration phases from a respiratory cycle are used to generate the velocity matrix using deformable image registrations such as the optical flow method (OFM) and B-spline algorithm. Interpolated phases are then obtained via linear, empirical, semi- or fully patient specific respiratory functions. The intepolated average CT (IACT) is obtained by averaging the original and interpolated phases for AC in static ECT while interpolated CTs (ICT) are used for phase-matched AC in respiratory or dual-gating ECT. The proposed method has been applied in both thoraic and abdominal ECT/CT and shows promising results. An active breathing controller prototype was proposed and developed for monitoring and controlling patients’ breathing to capture CTs at desired respiratory phases. Besides, for respiratory gating ECT, we have shown that amplitude-based gating is superior to phase gating for patients with different respiratory patterns.