Improved display and detection of small renal stones using photon-counting detector CT compared to conventional energy-integrating detector CT

• Published in: Abdominal imaging Vol. 50; no. 8; pp. 3572 - 3583
• Main Authors: Esquivel, Andrea, Potretzke, Theodora, Ferrero, Andrea, Inoue, Akitoshi, Hoodeshenans, Safa, Mileto, Achille, Winfree, Timothy, Yalon, Mariana, Khandelwal, Ashish, Rajendran, Kishore, Thorne, Jamison E., Lee, Yong S., Potretzke, Aaron, Leng, Shuai, McCollough, Cynthia H., Fletcher, Joel G.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.08.2025; Springer Nature B.V
• Subjects: Adult; Aged; Aged, 80 and over; Calculi; Classification; Clinical medicine; Computed tomography; Energy; Female; Gastroenterology; Hepatology; Humans; Image reconstruction; Imaging; Kidney Calculi - diagnostic imaging; Kidneys; Male; Medical imaging; Medicine; Medicine & Public Health; Middle Aged; Nephrolithiasis; Photons; Populations; Radiographic Image Interpretation, Computer-Assisted - methods; Radiology; Sensitivity; Sensitivity and Specificity; Sensors; Spatial discrimination; Spatial resolution; Tomography, X-Ray Computed - methods; Kidney calculi; Multi-energy; High spatial resolution; Computed tomography; Nephrolithiasis; Kidney calculi classification; Photon-counting detector
• ISSN: 2366-0058; 2366-004X; 2366-0058
• DOI: 10.1007/s00261-024-04781-z

Purpose To compare same-day photon-counting detector CT (PCD-CT) to conventional energy-integrating detector CT (EID-CT) for detection of small renal stones (≤ 3 mm). Methods Patients undergoing clinical dual-energy EID-CT for known or suspected stone disease underwent same-day research PCD-CT. Patients with greater than 10 stones and no visible stones under 3 mm were excluded. Three radiologists selected the optimal reconstruction configuration for each CT modality and created the reference standard for renal stone presence. Two other radiologists, blinded to imaging modality, independently reviewed anonymized images to detect renal stones, rating confidence in potential stones using a Likert scale (1 = Definitely present, 2 = Probably present, 3 = Questionably present, 4 = Not seen). Sensitivity and false positive detections for PCD and EID-CT were calculated. Results Twenty-one patients underwent clinical EID-CT followed by same-day PCD-CT, with the reference standard identifying 121 renal stones (mean size 2.8 ± 2.6 mm). 0.4-mm PCD-CT images were more likely to display a stone as definitely present compared to 1- or 2-mm EID-CT images (p < 0.0001). Overall sensitivity for detection of all stones was greater at PCD-CT (0.75 vs. 0.55, p < 0.05). Pooled sensitivity of stones ≤ 3 mm was also significantly higher at PCD-CT (0.67 vs. 0.41, p < 0.05), with false positive detections differing between readers and modalities (PCD-CT vs. EID-CT: R1—7 v. 5; R2 – 7 v. 1). Conclusion Sensitivity for renal stones was significantly higher using high spatial resolution PCD-CT vs. EID-CT, especially for stones 3 mm or less in size, which may be important for at-risk patient populations. Prospective evaluation in larger patient populations that will benefit from detection of small stones is warranted. Graphical abstract