公开(公告)号：US20210290195A1

公开(公告)日：2021-09-23

申请号：US16825857

申请日：2020-03-20

Applicant: CANON MEDICAL SYSTEMS CORPORATION

Inventor： Zhan XIAOHUI ,  Qiang YI ,  Zhihong YE

IPC: A61B6/00

Abstract: An apparatus and a method for correcting for signal variations in pixels of a main photoelectric conversion element in a radiation detection apparatus due to focal spot position drifts. Edge reference detectors are positioned next to the main detector, in the fan beam coverage but outside the scan field of view. The signal variations of the edge reference detector pixels under the ant-scatter grid shadow are used to estimate the real-time focal spot movement, which is used to estimate the shadow/signal variation on the main detector pixels that are in the scan field of view.