An Intra-Individual Comparison of Low-keV Photon-Counting CT versus Energy-Integrating-Detector CT Angiography of the Aorta

• Published in: Diagnostics (Basel) 2023-12, Vol.13 (24), p.3645
• Main Authors: Hennes, Jan-Lucca, Huflage, Henner, Grunz, Jan-Peter, Hartung, Viktor, Augustin, Anne Marie, Patzer, Theresa Sophie, Pannenbecker, Pauline, Petritsch, Bernhard, Bley, Thorsten Alexander, Gruschwitz, Philipp
• Format: Article
• Language: English
• Subjects: Abdomen; aorta; Contrast agents; Coronary vessels; CT angiography; Disease; Energy; Iodine; Medical imaging; Normal distribution; Patients; photon-counting-detector CT; Radiation; radiation dose reduction; Scanners; Sensors; spectral imaging; Statistical analysis; Tomography
• ISSN: 2075-4418; 2075-4418
• DOI: 10.3390/diagnostics13243645

This retrospective study aims to provide an intra-individual comparison of aortic CT angiographies (CTAs) using first-generation photon-counting-detector CT (PCD-CT) and third-generation energy-integrating-detector CT (EID-CT). High-pitch CTAs were performed with both scanners and equal contrast-agent protocols. EID-CT employed automatic tube voltage selection (90/100 kVp) with reference tube current of 434/350 mAs, whereas multi-energy PCD-CT scans were generated with fixed tube voltage (120 kVp), image quality level of 64, and reconstructed as 55 keV monoenergetic images. For image quality assessment, contrast-to-noise ratios (CNRs) were calculated, and subjective evaluation (overall quality, luminal contrast, vessel sharpness, blooming, and beam hardening) was performed independently by three radiologists. Fifty-seven patients (12 women, 45 men) were included with a median interval between examinations of 12.7 months (interquartile range 11.1 months). Using manufacturer-recommended scan protocols resulted in a substantially lower radiation dose in PCD-CT (size-specific dose estimate: 4.88 ± 0.48 versus 6.28 ± 0.50 mGy, < 0.001), while CNR was approximately 50% higher (41.11 ± 8.68 versus 27.05 ± 6.73, < 0.001). Overall image quality and luminal contrast were deemed superior in PCD-CT ( < 0.001). Notably, EID-CT allowed for comparable vessel sharpness ( = 0.439) and less pronounced blooming and beam hardening ( < 0.001). Inter-rater agreement was good to excellent (0.58-0.87). Concluding, aortic PCD-CTAs facilitate increased image quality with significantly lower radiation dose compared to EID-CTAs.