Image Quality Assessment for Clinical Cadmium Telluride-Based Photon-Counting Computed Tomography Detector in Cadaveric Wrist Imaging. Issue 12 (December 2021)

• Record Type: Journal Article
• Authors: Grunz, Jan-Peter; Huflage, Henner; Heidenreich, Julius Frederik; Ergün, Süleyman; Petersilka, Martin; Allmendinger, Thomas; Bley, Thorsten Alexander; Petritsch, Bernhard
• Is Part Of: Investigative radiology. Volume 56:Issue 12(2021)
• Publication Date: 2021-12
• Subjects: photon-counting -- tomography -- x-ray computed -- wrist -- radiation dosage -- cancellous bone; Diagnosis, Radioscopic -- Periodicals; Radiology, Medical -- Periodicals; 616.0757
• DOI: 10.1097/RLI.0000000000000789
• Languages: English
• ISSNs: 0020-9996

Abstract

Abstract : Objectives: Detailed visualization of bone microarchitecture is essential for assessment of wrist fractures in computed tomography (CT). This study aims to evaluate the imaging performance of a CT system with clinical cadmium telluride-based photon-counting detector (PCD-CT) compared with a third-generation dual-source CT scanner with energy-integrating detector technology (EID-CT). Materials and Methods: Both CT systems were used for the examination of 8 cadaveric wrists with radiation dose equivalent scan protocols (low-/standard-/full-dose imaging: CTDIvol = 1.50/5.80/8.67 mGy). All wrists were scanned with 2 different operating modes of the photon-counting CT (standard-resolution and ultra-high-resolution). After reformatting with comparable reconstruction parameters and convolution kernels, subjective evaluation of image quality was performed by 3 radiologists on a 7-point scale. For estimation of interrater reliability, we report the intraclass correlation coefficient (absolute agreement, 2-way random-effects model). Signal-to-noise and contrast-to-noise ratios were calculated to provide semiquantitative assessment of image quality. Results: Subjective image quality of standard-dose PCD-CT examinations in ultra-high-resolution mode was superior compared with full-dose PCD-CT in standard-resolution mode ( P = 0.016) and full-dose EID-CT ( P = 0.040). No difference was ascertained between low-dose PCD-CT in ultra-high-resolution mode and standard-dose scans with either PCD-CT in standard-resolution mode ( P = 0.108) or EID-CT ( P = 0.470). Observer evaluation of standard-resolution PCD-CT and EID-CT delivered similar results in full- and standard-dose scans ( P = 0.248/0.509). Intraclass correlation coefficient was 0.876 (95% confidence interval, 0.744–0.925; P < 0.001), indicating good reliability. Between dose equivalent studies, signal-to-noise and contrast-to-noise ratios were substantially higher in photon-counting CT examinations (all P 's < 0.001). Conclusions: Superior visualization of fine anatomy is feasible with the clinical photon-counting CT system in cadaveric wrist scans. The ultra-high-resolution scan mode suggests potential for considerable dose reduction over energy-integrating dual-source CT.