{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,23]],"date-time":"2026-10-23T20:03:29Z","timestamp":1792785809120,"version":"4.5.0"},"reference-count":44,"publisher":"Oxford University Press (OUP)","license":[{"start":{"date-parts":[[2026,10,9]],"date-time":"2026-10-09T00:00:00Z","timestamp":1791504000000},"content-version":"am","delay-in-days":1,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"the Minist\u00e8re de la Sant\u00e9 et des Services sociaux (MSSS) of Qu\u00e9bec (Canada) and the CIUSSS de l\u2019Estrie\u2014CHUS, Sherbrooke, Qu\u00e9bec","id":[{"id":"https:\/\/ror.org\/046r13h33","id-type":"ROR","asserted-by":"crossref"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Objectives<\/jats:title>\n                    <jats:p>To characterize recurrent computed tomography (CT) examinations and cumulative effective dose (CED) prevalence across observation periods of 1-5 years in a Canadian hospital network.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>Data from 8 CT scanners were analyzed for 2020-2024, with effective doses estimated from dose-length product using standard conversion factors. Cumulative prevalence of recurrent examinations and high CED was assessed across progressively longer observation periods.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>A total of 413\u00a0680 CT examinations were performed on 161\u00a0420 patients, of whom 26% were aged 50\u2009years or younger. Across 1-5 years, the proportions of patients undergoing 5 or more examinations were 3.8%, 7.0%, 9.6%, 12.2%, and 13.8%, respectively. Patients receiving CED \u2265100 mSv over the same periods were 0.6%, 1.1%, 1.6%, 2.0%, and 2.3%. Notably, 233 patients aged 30\u2009years or younger received a CED \u226550 mSv, representing 1.7% of all patients in this age group and 1.8% of all patients with a CED \u226550 mSv.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>Recurrent CT examinations and high CED were observed among younger patients within 5 years. These findings highlight the importance of ensuring imaging-referral appropriateness and optimizing radiological practices to minimize unnecessary radiation exposure. Monitoring CED and recurrent imaging may provide useful population-level indicators for reviewing imaging practices and supporting ongoing optimization and radiation-protection efforts.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Advances in knowledge<\/jats:title>\n                    <jats:p>This multi-period analysis provides population-level benchmarks for recurrent CT use and cumulative radiation exposure while clarifying how prevalence changes with observation-window length.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1093\/bjr\/tqag243","type":"journal-article","created":{"date-parts":[[2026,10,9]],"date-time":"2026-10-09T03:13:20Z","timestamp":1791515600000},"source":"Crossref","is-referenced-by-count":0,"title":["Recurrent computed tomography examinations and cumulative effective dose prevalence: a 5-year regional hospital network study"],"prefix":"10.1093","author":[{"given":"Moulay Ali","family":"Nassiri","sequence":"first","affiliation":[{"name":"Medical Imaging Research Axis, Centre de Recherche du CHUS , 12e Avenue Nord, aile 9 , Sherbrooke, QC, J1H 5N4,","place":["Canada"]},{"name":"Radiation Protection Department, Centre Int\u00e9gr\u00e9 Universitaire de Sant\u00e9 et de Services Sociaux de l\u2018Estrie \u2013 Centre Hospitalier Universitaire de Sherbrooke (CIUSSS de l\u2019Estrie-CHUS) , 12e Avenue Nord, aile 9 , Sherbrooke, QC, J1H 5N4,","place":["Canada"]},{"name":"Department of Nuclear Medicine and Radiobiology, Faculty of Medicine and Health Sciences, Sherbrooke University , Sherbrooke, QC J1H 5H3,","place":["Canada"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9101-4210","authenticated-orcid":false,"given":"Narjes","family":"Moghadam","sequence":"additional","affiliation":[{"name":"Medical Imaging Research Axis, Centre de Recherche du CHUS , 12e Avenue Nord, aile 9 , Sherbrooke, QC, J1H 5N4,","place":["Canada"]},{"name":"Radiation Protection Department, Centre Int\u00e9gr\u00e9 Universitaire de Sant\u00e9 et de Services Sociaux de l\u2018Estrie \u2013 Centre Hospitalier Universitaire de Sherbrooke (CIUSSS de l\u2019Estrie-CHUS) , 12e Avenue Nord, aile 9 , Sherbrooke, QC, J1H 5N4,","place":["Canada"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3967-4056","authenticated-orcid":false,"given":"St\u00e9phane","family":"Mercure","sequence":"additional","affiliation":[{"name":"Radiation Protection Department, Centre Int\u00e9gr\u00e9 Universitaire de Sant\u00e9 et de Services Sociaux de l\u2018Estrie \u2013 Centre Hospitalier Universitaire de Sherbrooke (CIUSSS de l\u2019Estrie-CHUS) , 12e Avenue Nord, aile 9 , Sherbrooke, QC, J1H 5N4,","place":["Canada"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3519-1516","authenticated-orcid":false,"given":"Madan M","family":"Rehani","sequence":"additional","affiliation":[{"name":"Radiology Department, Massachusetts General Hospital, Harvard Medical School , Boston, MA 02114,","place":["United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"286","published-online":{"date-parts":[[2026,10,8]]},"reference":[{"key":"2026102311514788800_tqag243-B1","author":"Cadth","year":"2023"},{"key":"2026102311514788800_tqag243-B2","author":"Unscear. 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