{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,27]],"date-time":"2026-08-27T14:32:10Z","timestamp":1787841130704,"version":"build-2784847793"},"reference-count":7,"publisher":"Ovid Technologies (Wolters Kluwer Health)","issue":"1","license":[{"start":{"date-parts":[[2026,1,1]],"date-time":"2026-01-01T00:00:00Z","timestamp":1767225600000},"content-version":"unspecified","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"}],"content-domain":{"domain":["lww.com","ovid.com"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[2026,1]]},"abstract":"\n Computed tomography (CT) produces cross-sectional images for medical diagnosis; however, in wide cone-beam CT, conventional CT dose index (CTDI) measurements using a 100-mm ionization chamber (IC) underestimate dose for larger beam widths. This study evaluated and compared CTDI measurements in wide beam using different methods for wide-beam CT, following International Atomic Energy Agency Human Health Report No. 5. Measurements were performed on an Aquilion\u2122 ONE CT scanner (160 mm beam width) using 100-and 300-mm ICs (Radcal 10 \u00d7 6\u20133CT and PTW TM30017). CTDI\n free-in-air<\/jats:sub>\n and weighted CTDI (CTDI\n w<\/jats:sub>\n ) were obtained under brain and abdomen protocols, both in free air and phantom conditions, at the Advanced Diagnostic Imaging Center, Faculty of Medicine Ramathibodi Hospital, Thailand. For free-in-air measurements at 80 mm beam width, CTDI\n 100<\/jats:sub>\n air<\/jats:sub>\n (no-step)<\/jats:sub>\n was slightly smaller than CTDI\n 300<\/jats:sub>\n air<\/jats:sub>\n with percentage differences of \u22121.27% and \u22121.94%, while CTDI\n 100air<\/jats:sub>\n (two-step)<\/jats:sub>\n showed +6.79% and +6.48% differences for brain and abdomen protocols, respectively. At 160 mm beam width, CTDI\n 100<\/jats:sub>\n air<\/jats:sub>\n (no-step)<\/jats:sub>\n was significantly lower due to incomplete dose coverage, whereas two-and three-step methods yielded slightly higher values. For CTDI\n w<\/jats:sub>\n at 80 mm, percentage differences were \u221217.06% and \u221215.05% (no-step), \u22123.29% and +1.88% (two-step), and \u22128.94% and \u22123.45% (calculated two-step) for brain and abdomen, respectively. At 160 mm, CTDI\n 100w<\/jats:sub>\n (no-step)<\/jats:sub>\n was 41.27% and 36.38% lower than CTDI\n 300W<\/jats:sub>\n , while CTDI\n 100w<\/jats:sub>\n (three-step)<\/jats:sub>\n exceeded CTDI\n 300w<\/jats:sub>\n due to scattering or overlap. Overall, CTDI measurements using a 100 mm IC underestimate dose for beam widths >NT +40 mm. The two-step technique is sufficient for wide-beam CT dosimetry measurements.\n <\/jats:p>","DOI":"10.4103\/jmp.jmp_275_25","type":"journal-article","created":{"date-parts":[[2026,3,31]],"date-time":"2026-03-31T19:01:00Z","timestamp":1774983660000},"page":"199-206","update-policy":"https:\/\/doi.org\/10.1097\/lww.0000000000001000","source":"Crossref","is-referenced-by-count":0,"title":["Computed Tomography Dose Index Measurements in Wide-beam Computed Tomography System"],"prefix":"10.4103","volume":"51","author":[{"given":"Sawwanee","family":"Asavaphatiboon","sequence":"first","affiliation":[{"name":"Department of Radiology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Suwadee","family":"Payomthip","sequence":"additional","affiliation":[{"name":"Department of Radiology, School of Medical Physics, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Prapa","family":"Sodkokkruad","sequence":"additional","affiliation":[{"name":"Department of Radiology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wichan","family":"Prasertsilpakul","sequence":"additional","affiliation":[{"name":"Advanced Diagnostic Imaging Center, Mission Support Unit, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tossaporn","family":"Iamsuk","sequence":"additional","affiliation":[{"name":"Advanced Diagnostic Imaging Center, Mission Support Unit, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Saifhon","family":"Ardmontree","sequence":"additional","affiliation":[{"name":"Advanced Diagnostic Imaging Center, Mission Support Unit, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Puangpen","family":"Tangboonduangjit","sequence":"additional","affiliation":[{"name":"Department of Radiology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"276","published-online":{"date-parts":[[2026,3,31]]},"reference":[{"key":"R2-20260403","article-title":"The Measurement, Reporting, and Management of Radiation Dose in CT","year":"2008"},{"key":"R3-20260403","doi-asserted-by":"crossref","first-page":"311","DOI":"10.1148\/radiol.11101800","article-title":"CT dose index and patient dose: They are not the same thing","volume":"259","author":"McCollough","year":"2011","journal-title":"Radiology"},{"key":"R4-20260403","doi-asserted-by":"crossref","first-page":"190","DOI":"10.1093\/rpd\/ncv187","article-title":"Dosimetry methods for multi-detector computed tomography","volume":"165","author":"Gancheva","year":"2015","journal-title":"Radiat Prot Dosimetry"},{"key":"R5-20260403","doi-asserted-by":"crossref","first-page":"1364","DOI":"10.1118\/1.2713240","article-title":"The trouble with CTD100","volume":"34","author":"Boone","year":"2007","journal-title":"Med Phys"},{"key":"R6-20260403","doi-asserted-by":"crossref","first-page":"1061","DOI":"10.1118\/1.1877852","article-title":"Enlarged longitudinal dose profiles in cone-beam CT and the need for modified dosimetry","volume":"32","author":"Mori","year":"2005","journal-title":"Med Phys"},{"key":"R9-20260403","article-title":"The Measurement, Reporting, and Management of Radiation Dose in CT","year":"2008"},{"key":"R10-20260403","doi-asserted-by":"crossref","first-page":"3141","DOI":"10.1088\/0031-9155\/54\/10\/012","article-title":"Computed tomography dose assessment for a 160 mm wide, 320 detector row, cone beam CT scanner","volume":"54","author":"Geleijns","year":"2009","journal-title":"Phys Med Biol"}],"container-title":["Journal of Medical Physics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.ovid.com\/10.4103\/jmp.jmp_275_25","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,8,27]],"date-time":"2026-08-27T13:42:46Z","timestamp":1787838166000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.ovid.com\/10.4103\/jmp.jmp_275_25"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,1]]},"references-count":7,"journal-issue":{"issue":"1","published-print":{"date-parts":[[2026]]}},"URL":"https:\/\/doi.org\/10.4103\/jmp.jmp_275_25","relation":{},"ISSN":["0971-6203","1998-3913"],"issn-type":[{"value":"0971-6203","type":"print"},{"value":"1998-3913","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,1]]},"assertion":[{"value":"2025-10-21","name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2026-01-20","name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}}]}}