title: Incidental Saccular Aneurysms on Head MR Angiography: 5 Years' Experience at a Single Large-Volume Center.
abstract: OBJECTIVE
  The diagnostic accuracy for unruptured intracranial aneurysms has increased, and incidental asymptomatic aneurysms have come to represent a substantial clinical burden because of their controversial natural history. However, their prevalence may be attributable to variations in evaluation methods and demographics. We therefore describe the prevalence and magnetic resonance angiography (MRA) findings of incidental intracranial saccular aneurysms over a 5-year period at a single large-volume center.
  
  
  METHODS
  MRA images from 18,237 patients obtained between January 2001 and December 2005 were retrieved from the radiology report database. Patients diagnosed with incidental intracranial saccular aneurysms were identified and their MRA data were reviewed. Imaging and clinical follow-up data were evaluated.
  
  
  RESULTS
  During the study period, 366 incidental intracranial saccular aneurysms were identified in 330 patients (prevalence, 1.8%; 95% confidence interval, 1.63%-2.01%; 115 men and 215 women; age range, 22-82 years; median age, 63 years). The prevalence was higher in women (215/8,112) than in men (115/10,125; P=0.02). The prevalence increased with age in women (P<0.01), but not in men (P=0.30). Aneurysm size ranged from 1.5 mm to 13 mm, with a median size of 4 mm. The most common location was the bifurcation of the middle cerebral artery (131/366; 35.8%).
  
  
  CONCLUSIONS
  Our real world experience indicated a slightly lower overall prevalence of incidental intracranial saccular aneurysms than previously reported. The prevalence increased with age in women but not in men.
authors.affiliation: Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea. ; Department of Radiology, Kyung Hee University Hospital at Gangdong, School of Medicine, Kyung Hee University, Seoul, Korea.
authors.forename: Soonchan
authors.initials: S
authors.lastname: Park
authors.affiliation: Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
authors.forename: Deok Hee
authors.initials: DH
authors.lastname: Lee
authors.affiliation: Department of Radiology, Kyung Hee University Hospital at Gangdong, School of Medicine, Kyung Hee University, Seoul, Korea.
authors.forename: Chang-Woo
authors.initials: CW
authors.lastname: Ryu
authors.affiliation: Department of Radiology, Pohang Stroke and Spine Hospital, Pohang, Korea.
authors.forename: Hae Wook
authors.initials: HW
authors.lastname: Pyun
authors.affiliation: Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
authors.forename: Choong Gon
authors.initials: CG
authors.lastname: Choi
authors.affiliation: Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
authors.forename: Sang Joon
authors.initials: SJ
authors.lastname: Kim
authors.affiliation: Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
authors.forename: Dae Chul
authors.initials: DC
authors.lastname: Suh
keywords: Aneurysm; Intracranial aneurysm; MRI angiography