Quantitative and qualitative image quality assessment in shoulder examinations with a first-generation photon-counting detector CT

• Published in: Scientific reports Vol. 13; no. 1; p. 8226
• Main Authors: Patzer, Theresa Sophie, Kunz, Andreas Steven, Huflage, Henner, Luetkens, Karsten Sebastian, Conrads, Nora, Gruschwitz, Philipp, Pannenbecker, Pauline, Ergün, Süleyman, Bley, Thorsten Alexander, Grunz, Jan-Peter
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 22.05.2023; Nature Publishing Group; Nature Portfolio
• Subjects: 692/698/1671; 692/698/1671/63; Cadavers; Computed tomography; Correlation coefficient; Humanities and Social Sciences; Humans; multidisciplinary; Phantoms, Imaging; Photons; Quality control; Reproducibility of Results; Science; Science (multidisciplinary); Sensors; Shoulder; Tomography, X-Ray Computed - methods
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-023-35367-2

Photon-counting detector (PCD) CT allows for ultra-high-resolution (UHR) examinations of the shoulder without requiring an additional post-patient comb filter to narrow the detector aperture. This study was designed to compare the PCD performance with a high-end energy-integrating detector (EID) CT. Sixteen cadaveric shoulders were examined with both scanners using dose-matched 120 kVp acquisition protocols (low-dose/full-dose: CTDI vol  = 5.0/10.0 mGy). Specimens were scanned in UHR mode with the PCD-CT, whereas EID-CT examinations were conducted in accordance with the clinical standard as “non-UHR”. Reconstruction of EID data employed the sharpest kernel available for standard-resolution scans (ρ 50  = 12.3 lp/cm), while PCD data were reconstructed with both a comparable kernel (11.8 lp/cm) and a sharper dedicated bone kernel (16.5 lp/cm). Six radiologists with 2–9 years of experience in musculoskeletal imaging rated image quality subjectively. Interrater agreement was analyzed by calculation of the intraclass correlation coefficient in a two-way random effects model. Quantitative analyses comprised noise recording and calculating signal-to-noise ratios based on attenuation measurements in bone and soft tissue. Subjective image quality was higher in UHR-PCD-CT than in EID-CT and non-UHR-PCD-CT datasets (all p < 0.001). While low-dose UHR-PCD-CT was considered superior to full-dose non-UHR studies on either scanner (all p < 0.001), ratings of low-dose non-UHR-PCD-CT and full-dose EID-CT examinations did not differ (p > 0.99). Interrater reliability was moderate, indicated by a single measures intraclass correlation coefficient of 0.66 (95% confidence interval: 0.58–0.73; p < 0.001). Image noise was lowest and signal-to-noise ratios were highest in non-UHR-PCD-CT reconstructions at either dose level (p < 0.001). This investigation demonstrates that superior depiction of trabecular microstructure and considerable denoising can be realized without additional radiation dose by employing a PCD for shoulder CT imaging. Allowing for UHR scans without dose penalty, PCD-CT appears as a promising alternative to EID-CT for shoulder trauma assessment in clinical routine.