Purpose: Legislation imposes the verification of compliance with acceptability criteria of (new) x-ray devices at their first installation in a hospital, and from then annually. In this study, QC measurements obtained from an emerging photon counting CT scanner (PCCT) are compared to 53 state-of-the-art CT scanners in routine clinical use.

Material and methods: The Belgian acceptance test protocol is applied by a team of three medical physicists on 53 scanners (33 distinctive models, 5 manufacturers) as well as on the PCCT (Naeotom, Siemens-Healthineers, Germany). Intersystem comparisons were achieved by pooling the QC data of 213 annual tests between 2016 and 2021 into a central relational database (DB) that was newly developed to improve the quality of reports and interpretation. Several test results will be illustrated in present study, including the spatial resolution from full width half maximum of a 0.28 mm bead, the accuracy of Hounsfield Unit of water using filtered back projection and iterative reconstruction, and longitudinal follow-up of CTDI_vol for 120 kVp/100 mAs.

Results: The database is a flexible, user-friendly platform that shows typical results for CT scanners of different make and model. It confirms the stability of most CT scanners and the choice of limiting values in current CT protocols. The new PCCT compared favorably to the other scanners and passed all acceptability criteria.