Jessica D Flores, Gavin Poludniowski, Adrian Szum, Georg Walther, Johan Lundberg, Patrik Nowik, Tobias Granberg
{"title":"Clinical photon-counting CT increases CT number precision and reduces patient size dependence compared to single- and dual- energy CT.","authors":"Jessica D Flores, Gavin Poludniowski, Adrian Szum, Georg Walther, Johan Lundberg, Patrik Nowik, Tobias Granberg","doi":"10.1093/bjr/tqaf052","DOIUrl":null,"url":null,"abstract":"<p><strong>Objectives: </strong>To study whether photon-counting computed tomography (PCCT) can improve CT number accuracy, precision and reduce patient size dependence compared to dual-energy CT (DECT) virtual monoenergetic imaging (VMI) and single-energy CT (SECT).</p><p><strong>Methods: </strong>Clinical PCCT, DECT and SECT scanners were used to image a multi-energy quality assurance phantom and tissue-equivalent inserts with/without an outer nested annulus, representing two object sizes (18 and 33 cm). CT numbers were converted to linear attenuation coefficients (LAC) and regions-of-interest applied. Theoretical monoenergetic LAC were calculated from known elemental compositions as a ground truth. Percent difference in mean LAC between phantom sizes, between mean and theoretical LAC, and its coefficient of variation (COV) were calculated.</p><p><strong>Results: </strong>Mean LAC percent differences between small and larger phantoms were highest in DECT (within -3% to 9%) and SECT (within 1% to 5%), particularly at higher calcium and iodine concentrations, while being relatively constant in PCCT over material concentrations and VMI energies (within ±2%). The COV in mean LAC was consistently lower (about 2 to 5 times) in PCCT relative to DECT and SECT for calcium in the large phantom. With consideration of the theoretical uncertainties of 2%, both PCCT and DECT showed comparable agreement to theoretical LAC.</p><p><strong>Conclusions: </strong>PCCT VMI produces CT numbers with less dependence on patient size and increased precision in large object sizes than DECT VMI and SECT.</p><p><strong>Advances in knowledge: </strong>Clinical PCCT provides less variable CT numbers than DECT and SECT with less sensitivity to the imaged object size.</p>","PeriodicalId":9306,"journal":{"name":"British Journal of Radiology","volume":" ","pages":""},"PeriodicalIF":1.8000,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"British Journal of Radiology","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1093/bjr/tqaf052","RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING","Score":null,"Total":0}
引用次数: 0
Abstract
Objectives: To study whether photon-counting computed tomography (PCCT) can improve CT number accuracy, precision and reduce patient size dependence compared to dual-energy CT (DECT) virtual monoenergetic imaging (VMI) and single-energy CT (SECT).
Methods: Clinical PCCT, DECT and SECT scanners were used to image a multi-energy quality assurance phantom and tissue-equivalent inserts with/without an outer nested annulus, representing two object sizes (18 and 33 cm). CT numbers were converted to linear attenuation coefficients (LAC) and regions-of-interest applied. Theoretical monoenergetic LAC were calculated from known elemental compositions as a ground truth. Percent difference in mean LAC between phantom sizes, between mean and theoretical LAC, and its coefficient of variation (COV) were calculated.
Results: Mean LAC percent differences between small and larger phantoms were highest in DECT (within -3% to 9%) and SECT (within 1% to 5%), particularly at higher calcium and iodine concentrations, while being relatively constant in PCCT over material concentrations and VMI energies (within ±2%). The COV in mean LAC was consistently lower (about 2 to 5 times) in PCCT relative to DECT and SECT for calcium in the large phantom. With consideration of the theoretical uncertainties of 2%, both PCCT and DECT showed comparable agreement to theoretical LAC.
Conclusions: PCCT VMI produces CT numbers with less dependence on patient size and increased precision in large object sizes than DECT VMI and SECT.
Advances in knowledge: Clinical PCCT provides less variable CT numbers than DECT and SECT with less sensitivity to the imaged object size.
期刊介绍:
BJR is the international research journal of the British Institute of Radiology and is the oldest scientific journal in the field of radiology and related sciences.
Dating back to 1896, BJR’s history is radiology’s history, and the journal has featured some landmark papers such as the first description of Computed Tomography "Computerized transverse axial tomography" by Godfrey Hounsfield in 1973. A valuable historical resource, the complete BJR archive has been digitized from 1896.
Quick Facts:
- 2015 Impact Factor – 1.840
- Receipt to first decision – average of 6 weeks
- Acceptance to online publication – average of 3 weeks
- ISSN: 0007-1285
- eISSN: 1748-880X
Open Access option