Image-Based Geometric Calibration Of A Hybrid Ct System With A Flat Photon-Counting Detector Insert In A Standard Ct Scanner

A hybrid imaging system consisting of a standard CT scanner and a photon-counting detector insert in direct contact with the patient’s body has been used to produce ultrahigh-resolution scans in a limited z length [1,2]. The position of the contact detector insert (CDI) is patient dependent and not known a priori. To address this challenge, we present a method of geometric calibration for each scan using fiducial markers. This method uses an iterative registration algorithm to align the markers in the CDI’s reconstructed volume to that of the con-current CT scan. After obtaining precise geometric information of the CDI relative to the CT scanner, the two complementary sources of data are fused (summed) together to create a detailed image with reduced artifacts.