{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,24]],"date-time":"2026-10-24T02:36:57Z","timestamp":1792809417316,"version":"4.5.0"},"reference-count":9,"publisher":"Journal of Neurosurgery Publishing Group (JNSPG)","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2018,4]]},"abstract":"\n OBJECTIVE<\/jats:title>\n The purpose of this study was to evaluate the detection rate and occurrence site according to patient sex and age of unruptured intracranial aneurysms detected through MRI and MR angiography (MRA).<\/jats:p>\n <\/jats:sec>\n \n METHODS<\/jats:title>\n A total of 4070 healthy adults 22 years or older (mean age [\u00b1 SD] 50.6 \u00b1 11.0 years; 41.9% women) who underwent a brain examination known as \u201cBrain Dock\u201d in the central Tokyo area between April 2014 and March 2015 were checked for unruptured saccular aneurysm using 3-T MRI\/MRA. The following types of cases were excluded: 1) protrusions with a maximum diameter < 2 mm at locations other than arterial bifurcations, 2) conical protrusions at arterial bifurcations with a diameter < 3 mm, and 3) cases of suspected aneurysms with unclear imaging of the involved artery. When an aneurysm was definitively diagnosed, the case was included in the aneurysm group. The authors also investigated the relationship between aneurysm occurrence and risk factors (age, sex, smoking history, hypertension, diabetes, and hyperlipidemia).<\/jats:p>\n <\/jats:sec>\n \n RESULTS<\/jats:title>\n \n One hundred eighty-eight aneurysms were identified in 176 individuals (detection rate 4.32%), with the detection rate for women being significantly higher (6.2% vs 3.0%, p < 0.001). The average age in the aneurysm group was significantly higher than in the patients in whom aneurysms were not detected (53.0 \u00b1 11.1 vs 50.5 \u00b1 11.0 years). The detection rate tended to increase with age. The detection rates were 3.6% for people in their 30s, 3.5% for those in their 40s, 4.1% for those in their 50s, 6.9% for those in their 60s, and 6.8% for those in their 70s. Excluding persons in their 20s and 80s\u2014age groups in which no aneurysms were discovered\u2014the detection rate in women was higher in all age ranges. Of the individuals with aneurysms, 12 (6.81%) had multiple cerebral aneurysms; no sex difference was observed with respect to the prevalence of multiple aneurysms. Regarding aneurysm size, 2.0\u20132.9 mm was the most common size range, with 87 occurrences (46.3%), followed by 3.0\u20133.9 mm (67 [35.6%]) and 4.0\u20134.9 mm (20 [10.6%]). The largest aneurysm was 13 mm. Regarding location, the internal carotid artery (ICA) was the most common aneurysm site, with 148 (78.7%) occurrences. Within the ICA, C\n 1<\/jats:sub>\n was the site of 46 aneurysms (24.5%); C\n 2<\/jats:sub>\n , 57 (30.3%); and C\n 3<\/jats:sub>\n , 29 (15.4%). The aneurysm detection rates for C\n 2<\/jats:sub>\n , C\n 3<\/jats:sub>\n , and C\n 4<\/jats:sub>\n were 2.23%, 1.23%, and 0.64%, respectively, for women and 0.68%, 0.34%, and 0.21%, respectively, for men; ICA aneurysms were significantly more common in women than in men (5.27% vs 2.20%, p < 0.001). Multivariate logistic regression analysis revealed that age (p < 0.001, OR 1.03, 95% CI 1.01\u20131.04), female sex (p < 0.001, OR 2.28, 95% CI 1.64\u20133.16), and smoking history (p = 0.011, OR 1.52, 95% CI 1.10\u20132.11) were significant risk factors for aneurysm occurrence\n <\/jats:p>\n <\/jats:sec>\n \n CONCLUSIONS<\/jats:title>\n In this study, both female sex and older age were independently associated with an increased aneurysm detection rate. Aneurysms were most common in the ICA, and the frequency of aneurysms in ICA sites was markedly higher in women.<\/jats:p>\n <\/jats:sec>","DOI":"10.3171\/2017.9.jns171191","type":"journal-article","created":{"date-parts":[[2018,4,6]],"date-time":"2018-04-06T09:59:15Z","timestamp":1523008755000},"page":"1-6","source":"Crossref","is-referenced-by-count":48,"title":["Detection rates and sites of unruptured intracranial aneurysms according to sex and age: an analysis of MR angiography\u2013based brain examinations of 4070 healthy Japanese adults"],"prefix":"10.3171","author":[{"given":"Yohichi","family":"Imaizumi","sequence":"first","affiliation":[{"name":"Department of Neurosurgery, Showa University School of Medicine; and"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tohru","family":"Mizutani","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, Showa University School of Medicine; and"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Katsuyoshi","family":"Shimizu","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, Showa University School of Medicine; and"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yosuke","family":"Sato","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, Showa University School of Medicine; and"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Junichi","family":"Taguchi","sequence":"additional","affiliation":[{"name":"Tokyo Midtown Medical Center, Tokyo, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1754","reference":[{"key":"b1","series-title":"Zentralbl Neurochir","first-page":"300","article-title":"Die Lageabweichungen der vorderen Hirnarterie im Gefassbild","volume":"3","author":"Fischer E","year":"1938","unstructured":"Fischer E: Die Lageabweichungen der vorderen Hirnarterie im Gefassbild. 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