{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T10:04:45Z","timestamp":1790762685374,"version":"4.1.0"},"reference-count":20,"publisher":"Springer Science and Business Media LLC","issue":"1","license":[{"start":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T00:00:00Z","timestamp":1790726400000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T00:00:00Z","timestamp":1790726400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"funder":[{"DOI":"10.13039\/501100004699","name":"Chung Shan Medical University Hospital","doi-asserted-by":"publisher","award":["CSH-2019-C-007"],"award-info":[{"award-number":["CSH-2019-C-007"]}],"id":[{"id":"10.13039\/501100004699","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["Eur Radiol Exp"],"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Objective<\/jats:title>\n                    <jats:p>68-keV monoenergetic images from dual-energy CT are often compared with conventional 120-kVp CT, but quantitative performance may depend on phantom size, reconstruction method, and dose settings. We performed a technical phantom-based comparison of 68-keV monoenergetic, routine-dose, and low-dose 120-kVp CT for calcium-mimicking inserts.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Materials and methods<\/jats:title>\n                    <jats:p>In this phantom study, a thorax phantom with a cardiac calcification insert was scanned using routine-dose 120-kVp CT, low-dose 120-kVp CT, and dual-energy CT with 68-keV monoenergetic reconstruction. Small- and large-phantom conditions were created without and with an extension ring. Images were reconstructed at 2.5-mm slice thickness using filtered back projection (FBP), iterative reconstruction (IR), and deep-learning reconstruction (DL). Mean attenuation, background noise, contrast-to-noise ratio (CNR), and figure of merit (FOM, CNR\u00b2\/CTDIvol) were summarized descriptively. Repeated scans and repeated region of interest redraws were not performed.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>For both 5-mm and 3-mm inserts, attenuation generally increased with hydroxyapatite (HA) density. The with-ring condition showed higher background noise and lower CNR. DL showed the most favorable descriptive quantitative results. Under most conditions, 68-keV imaging showed the highest CNR, followed by routine-dose and low-dose 120-kVp CT; however, it was also associated with the highest CTDIvol. When the dose was evaluated using FOM, the differences among the three strategies were smaller.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>In this technical phantom study, 68-keV monoenergetic imaging showed a descriptively higher CNR than routine-dose and low-dose 120-kVp CT, but this was accompanied by a higher radiation dose. Dose-normalized performance was more comparable across strategies. Findings should be interpreted as descriptive condition-level comparisons rather than statistically tested superiority.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Key Points<\/jats:title>\n                    <jats:p>\n                      <jats:bold>\n                        <jats:italic>Question<\/jats:italic>\n                      <\/jats:bold>\n                      How do 68-keV monoenergetic, routine-dose 120-kVp, and low-dose 120-kVp CT differ in conspicuity and dose-normalized performance for calcium-mimicking targets?\n                    <\/jats:p>\n                    <jats:p>\n                      <jats:bold>\n                        <jats:italic>Findings<\/jats:italic>\n                      <\/jats:bold>\n                      68-keV imaging generally yielded the highest CNR, but also the highest CTDIvol; when dose was considered using FOM, performance differences became smaller.\n                    <\/jats:p>\n                    <jats:p>\n                      <jats:bold>\n                        <jats:italic>Relevance statement<\/jats:italic>\n                      <\/jats:bold>\n                      This phantom study provides a technical framework for calcium-focused CT protocol optimization by comparing conspicuity, radiation dose, and dose-normalized performance across monoenergetic and conventional acquisitions.\n                    <\/jats:p>\n                  <\/jats:sec>","DOI":"10.1186\/s41747-026-00818-8","type":"journal-article","created":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T09:35:32Z","timestamp":1790760932000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Quantitative comparison of 68-keV monoenergetic, routine-dose, and low-dose 120-kVp CT for calcium-mimicking inserts in thoracic phantoms: effects of phantom size and reconstruction method"],"prefix":"10.1186","volume":"10","author":[{"given":"Yeu-Sheng","family":"Tyan","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ya-Yun","family":"Hsiao","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Cheng-Chang","family":"Lu","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7324-9312","authenticated-orcid":false,"given":"Tou-Rong","family":"Chen","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2026,9,30]]},"reference":[{"key":"818_CR1","doi-asserted-by":"publisher","first-page":"827","DOI":"10.1016\/0735-1097(90)90282-T","volume":"15","author":"AS Agatston","year":"1990","unstructured":"Agatston AS, Janowitz WR, Hildner FJ, Zusmer NR, Viamonte M Jr, Detrano R (1990) Quantification of coronary artery calcium using ultrafast computed tomography. 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