{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,2]],"date-time":"2026-09-02T22:45:50Z","timestamp":1788389150599,"version":"build-2803163510"},"reference-count":47,"publisher":"MDPI AG","issue":"23","license":[{"start":{"date-parts":[[2025,12,2]],"date-time":"2025-12-02T00:00:00Z","timestamp":1764633600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Background: Photon-counting computed tomography (PCCT) represents a major technological advance in clinical CT imaging, offering superior spatial resolution, enhanced material discrimination, and potential radiation dose reduction compared to conventional energy-integrating detector systems. As the first clinically approved PCCT scanner becomes available, establishing a comprehensive characterization of its image quality is essential to understand its performance and clinical impact. Methods: Image quality was evaluated using a commercial quality assurance phantom with acquisition protocols typically used for three anatomical regions\u2014head, abdomen\/thorax, and inner ear\u2014representing diverse clinical scenarios. Each region was scanned using both ultra-high-resolution (UHR, 120 \u00d7 0.2 mm slices) and conventional (144 \u00d7 0.4 mm slices) protocols. Conventional metrics, including signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), slice thickness accuracy, and uniformity, were assessed following international standards. Task-based analysis was also performed through target transfer function (TTF), noise power spectrum (NPS), and detectability index (d\u2032) to evaluate diagnostic relevance. Results: UHR protocols provided markedly improved spatial resolution, particularly in the inner ear imaging, as confirmed by TTF analysis, though with increased noise and reduced low-contrast detectability in certain conditions. CT numbers showed linear correspondence with known attenuation coefficients across all protocols. Conclusions: This study establishes a detailed technical characterization of the first clinical PCCT scanner, demonstrating significant improvements in terms of spatial resolution and accuracy of the quantitative image analysis, while highlighting the need for noise\u2013contrast optimization in high-resolution imaging.<\/jats:p>","DOI":"10.3390\/s25237338","type":"journal-article","created":{"date-parts":[[2025,12,5]],"date-time":"2025-12-05T18:42:02Z","timestamp":1764960122000},"page":"7338","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Assessment of Image Quality Performance of a Photon-Counting Computed Tomography Scanner Approved for Whole-Body Clinical Applications"],"prefix":"10.3390","volume":"25","author":[{"ORCID":"https:\/\/orcid.org\/0009-0007-3331-9738","authenticated-orcid":false,"given":"Francesca Saveria","family":"Maddaloni","sequence":"first","affiliation":[{"name":"Department of Physics \u2018Aldo Pontremoli\u2019, University of Milan, 20133 Milan, Italy"},{"name":"Milano Division, National Institute for Nuclear Physics, 20133 Milan, Italy"},{"name":"Medical Phyisics Department, IRCCS San Raffaele Hospital, 20132 Milan, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3034-7166","authenticated-orcid":false,"given":"Antonio","family":"Sarno","sequence":"additional","affiliation":[{"name":"Department of Physics \u2018Aldo Pontremoli\u2019, University of Milan, 20133 Milan, Italy"},{"name":"Milano Division, National Institute for Nuclear Physics, 20133 Milan, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3274-7008","authenticated-orcid":false,"given":"Alessandro","family":"Loria","sequence":"additional","affiliation":[{"name":"Medical Phyisics Department, IRCCS San Raffaele Hospital, 20132 Milan, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2126-4796","authenticated-orcid":false,"given":"Anna","family":"Piai","sequence":"additional","affiliation":[{"name":"Medical Phyisics Department, IRCCS San Raffaele Hospital, 20132 Milan, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Cristina","family":"Lenardi","sequence":"additional","affiliation":[{"name":"Department of Physics \u2018Aldo Pontremoli\u2019, University of Milan, 20133 Milan, Italy"},{"name":"Milano Division, National Institute for Nuclear Physics, 20133 Milan, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Antonio","family":"Esposito","sequence":"additional","affiliation":[{"name":"Experimental Imaging Center, Vita-Salute San Raffaele University, 20132 Milan, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7889-7896","authenticated-orcid":false,"given":"Antonella","family":"del Vecchio","sequence":"additional","affiliation":[{"name":"Medical Phyisics Department, IRCCS San Raffaele Hospital, 20132 Milan, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,12,2]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2277","DOI":"10.1056\/NEJMra072149","article-title":"Computed Tomography\u2014An Increasing Source of Radiation Exposure","volume":"357","author":"Brenner","year":"2007","journal-title":"N. 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