title: Prevalence of Asymptomatic Unruptured Intracranial Aneurysms in a Southeast Asian Population.
abstract: BACKGROUND
  The prevalence of asymptomatic unruptured intracranial aneurysms (AUIA) in a Southeast Asian population has not been previously studied. Knowing the disease burden and population at risk can assist us in making informed decisions when managing AUIAs. We aimed to determine if the local prevalence of AUIAs differed from other populations in the published literature.
  
  
  METHODS
  Magnetic resonance angiography radiology reports and images for 4572 patients between January 2013 and January 2014 were reviewed for AUIAs.
  
  
  RESULTS
  The overall prevalence of AUIAs was 3.5% (160/4572). It was significantly higher in women (4.5%) compared with men (2.6%) (P < 0.001). The mean aneurysm size was 3.2 ± 1.7 mm. Of the aneurysms, 88.5% (146/165) measured less than 5 mm, 9.7% (16/165) measured 5-9 mm, and 1.8% (3/165) measured more than 9 mm. Most of the aneurysms were located in the cavernous segment (72/165, 43.6%) and ophthalmic segment (34/165, 20.6%) of the internal carotid artery, followed by the middle cerebral artery (16/165, 9.7%). The posterior circulation contributed 9.1% (15/165) of the AUIAs. During the study period, 1 aneurysm ruptured and the rest of the aneurysms did not show any growth.
  
  
  CONCLUSIONS
  In this large cohort of a Southeast Asian population, the prevalence of AUIA was 3.5%. Most of the AUIAs were less than 5 mm and did not require intervention at time of discovery and did not progress within the year of follow-up.
authors.affiliation: Department of Neurosurgery, National Neuroscience Institute, Singapore. Electronic address: ady_thien@nni.com.sg.
authors.forename: Ady
authors.initials: A
authors.lastname: Thien
authors.affiliation: Department of Neurosurgery, National Neuroscience Institute, Singapore.
authors.forename: Angela An Qi
authors.initials: AA
authors.lastname: See
authors.affiliation: Department of Neurosurgery, National Neuroscience Institute, Singapore.
authors.forename: Samantha Ya Lyn
authors.initials: SY
authors.lastname: Ang
authors.affiliation: Department of Neurosurgery, National Neuroscience Institute, Singapore.
authors.forename: Nishal Kishinchand
authors.initials: NK
authors.lastname: Primalani
authors.affiliation: Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
authors.forename: Mervyn Jun Rui
authors.initials: MJ
authors.lastname: Lim
authors.affiliation: Department of Neurosurgery, National Neuroscience Institute, Singapore.
authors.forename: Yew Poh
authors.initials: YP
authors.lastname: Ng
authors.affiliation: Department of Neurosurgery, National Neuroscience Institute, Singapore.
authors.forename: Nicolas Kon Kam
authors.initials: NK
authors.lastname: King
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D017542:Aneurysm, Ruptured / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D058070:Asymptomatic Diseases / Q000453:epidemiology*; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D018810:Magnetic Resonance Angiography / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012307:Risk Factors; D017678:Sex Distribution; D012846:Singapore / Q000453:epidemiology
keywords: Angiography; Asymptomatic conditions; Cerebral aneurysm; Imaging; Intracranial aneurysm; Magnetic resonance imaging (MRI)