Prevalence of unruptured intracranial aneurysm on MR angiography

Korean J Radiol. Sep-Oct 2011;12(5):547-53. doi: 10.3348/kjr.2011.12.5.547. Epub 2011 Aug 24.

Abstract

Objective: To evaluate the prevalence of incidentally found unruptured intracranial aneurysms (UIAs) on the brain MR angiography (MRA) from a community-based general hospital.

Materials and methods: This was a prospectively collected retrospective study, carried out from January 2004 to December 2004. The subjects included 3049 persons from a community-based hospital in whom MRA was performed according to a standardized protocol in an outpatient setting. Age- and sex-specific prevalence of UIAs was calculated. The results by MRA were compared with intra-arterial digital subtraction angiography (DSA) findings.

Results: Unruptured intracranial aneurysms were found in 137 (5%) of the 3049 patients (M:F = 43:94; mean age, 60.2 years). The prevalence of UIAs was 5% (n = 94) in women and 4% (n = 43) in men, respectively (p = 0.2046) and showed no age-related increase. The most common site of aneurysm was at the distal internal carotid artery (n = 64, 39%), followed by the middle cerebral artery (n = 40, 24%). In total, 99% of aneurysms measured less than 12 mm, and 93% of aneurysms measured less than 7 mm. Direct comparisons between MRA and DSA were available in 70 patients with 83 UIAs; the results revealed two false positive and two false negative results.

Conclusion: This community-hospital based study suggested a higher prevalence of UIAs observed by MRA than previously reported. These findings should be anticipated in the design and use of neuroimaging in clinical practice.

Keywords: Intracranial aneurysm; MR angiography; Prevalence.

Publication types

  • Comparative Study

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Aneurysm, Ruptured / diagnosis
  • Angiography, Digital Subtraction
  • Cerebral Angiography
  • Female
  • Humans
  • Incidental Findings
  • Intracranial Aneurysm / diagnosis*
  • Intracranial Aneurysm / diagnostic imaging
  • Magnetic Resonance Angiography*
  • Male
  • Middle Aged
  • Young Adult