title: Quantifying unruptured giant intracranial aneurysms by measuring diameter and volume--a comparative analysis of 69 cases.
abstract: BACKGROUND
  Intracranial aneurysms (IA) are usually quantified according to their largest diameter. However, volumetry has recently been increasingly conducted as well, especially in giant intracranial aneurysms (GIAs). Since so far the true value of GIA volumetry is unknown, we designed a trial to examine correlations between GIA diameter and volume with special focus on clinical implications.
  
  
  METHODS
  Magnetic resonance imaging of 69 unruptured GIAs in 66 patients was retrospectively evaluated. The largest diameter and volume were measured. Also, potential associations to the patients' clinical conditions were examined.
  
  
  RESULTS
  Comparing GIA sizes of our patient cohort produced different results depending on whether GIA diameter or volume was measured. Measuring the diameter identified posterior circulation GIAs as the largest ones (39.2 mm, IQR 37.3-48.3), while measuring the volume found GIAs of the MCA to be the largest ones (12.3 cm(3), IQR 7.2-27.8). A correlation of GIA diameter and volume was only found in anterior circulation GIAs, which were predominantly saccular in shape, but not in those of the posterior circulation, of which most were fusiform. Neither GIA diameter nor GIA volume but only GIA location was associated with neurological deficits.
  
  
  CONCLUSIONS
  Diameter and volume measurements are not interchangeable modes of GIA quantification. Our data suggest that the idea of distinguishing different sizes of GIA may be clinically less relevant than examining their location, shape or mass effect.
authors.affiliation: Department of Neurosurgery, Charité-Universitaetsmedizin Berlin, Campus Virchow Klinikum (CVK), Augustenburger Platz 1, 13353, Berlin, Germany, julius.dengler@charite.de.
authors.forename: Julius
authors.initials: J
authors.lastname: Dengler
authors.forename: Nicolai
authors.initials: N
authors.lastname: Maldaner
authors.forename: Philippe
authors.initials: P
authors.lastname: Bijlenga
authors.forename: Jan-Karl
authors.initials: JK
authors.lastname: Burkhardt
authors.forename: Alexander
authors.initials: A
authors.lastname: Graewe
authors.forename: Susanne
authors.initials: S
authors.lastname: Guhl
authors.forename: Makoto
authors.initials: M
authors.lastname: Nakamura
authors.forename: Christian
authors.initials: C
authors.lastname: Hohaus
authors.forename: Adisa
authors.initials: A
authors.lastname: Kursumovic
authors.forename: Nils Ole
authors.initials: NO
authors.lastname: Schmidt
authors.forename: Karl-Michael
authors.initials: KM
authors.lastname: Schebesch
authors.forename: Maria
authors.initials: M
authors.lastname: Wostrack
authors.forename: Peter
authors.initials: P
authors.lastname: Vajkoczy
authors.forename: Dorothee
authors.initials: D
authors.lastname: Mielke
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies