Assessment of a photon-counting detector for a dual-energy C-arm angiographic system

作者:Ahmad Moiz*; Fahrig Rebecca; Pung Leland; Spahn Martin; Koester Niko S; Reitz Silke; Moore Teri; Choi Jang Hwan; Hinshaw Waldo; Xia Yan; Mueller Kerstin
来源:Medical Physics, 2017, 44(11): 5938-5948.
DOI:10.1002/mp.12517

摘要

PurposeThis article presents the implementation and assessment of photon-counting dual-energy x-ray detector technology for angiographic C-arm systems in interventional radiology. MethodsA photon-counting detector was successfully integrated into a clinical C-arm CT system. Detector performance was assessed using image uniformity metrics in both 2D projections and 3D cone-beam computed tomography (CBCT) images. Uniform exposure fields were acquired to analyze projection images and scans of a homogeneous cylinder phantom were taken to analyze 3D reconstructions. Image uniformity was assessed over a broad range of imaging parameters. ResultsDetector calibration greatly improved image uniformity, reducing image variation from 8.8% to 0.5% in an ideal scenario, but image uniformity degraded when imaging parameters varied strongly from values set at calibration: the tube voltage, low-high energy threshhold, and tube current had the greatest impact. Material discrimination and dynamic angiography capabilities were successfully demonstrated in separate phantom and invivo experiments. ConclusionThe uniformity results identified major factors degrading image quality. The quantitative results will guide selection of calibration points to mitigate the loss of uniformity. The unique combination of dual-energy and fluoroscopy imaging capabilities with a flat-panel photon-counting detector may enable new applications in interventional radiology.

  • 出版日期2017-11