title: Asymptomatic microbleeds in moyamoya disease: T2*-weighted gradient-echo magnetic resonance imaging study.
abstract: OBJECTIVE
  The aim of this study was to investigate the incidence of asymptomatic microbleeds (MBs) in patients with moyamoya disease (MMD) by using a 3-tesla magnetic resonance (MR) imaging unit.
  
  
  METHODS
  Data on 63 patients hospitalized with MMD between 1999 and 2004 were retrospectively examined to determine the incidence of asymptomatic MBs. Gradient-echo T2*-weighted MR imaging studies obtained using 3- and 1.5-tesla units were available in 25 patients. These patients consisted of five men and 20 women, ranging in age from 17 to 66 years (mean age 41 +/- 14 years). Ischemic MMD was diagnosed in 18 patients, and hemorrhagic MMD in seven. The incidence of MBs was also evaluated using the same 3-tesla MR imaging unit in 34 healthy volunteers including seven men and 27 women, ranging in age from 18 to 71 years (mean age 33 +/- 12 years). Using the 3-tesla MR unit, asymptomatic MBs were demonstrated in 11 patients (44%); they were detected in seven patients (28%) by using the 1.5-tesla unit. In the 3-tesla MR studies in healthy individuals, MBs were found in two patients (5.8%). Based on 3-tesla MR studies, the incidence of MBs was significantly higher in patients with MMD compared with that in healthy individuals. Asymptomatic MBs were demonstrated in eight (44%) of 18 patients with ischemic MMD and three (43%) of seven patients with hemorrhagic MMD.
  
  
  CONCLUSIONS
  Microbleeds are significantly more common in patients with MMD than in healthy individuals regardless of the disease type. The evaluation of MBs with T2*-weighted 3-tesla MR imaging might contribute to the treatment of MMD.
authors.affiliation: Department of Neurosurgery, Kyoto University Graduate School of Medicine, Japan. kikuta@kuhp.kyoto-u.ac.jp
authors.forename: Ken-Ichiro
authors.initials: K
authors.lastname: Kikuta
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Takagi
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Nozaki
authors.forename: Takashi
authors.initials: T
authors.lastname: Hanakawa
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Okada
authors.forename: Nobuhro
authors.initials: N
authors.lastname: Mikuni
authors.forename: Yukio
authors.initials: Y
authors.lastname: Miki
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Fushmi
authors.forename: Akira
authors.initials: A
authors.lastname: Yamamoto
authors.forename: Keisuke
authors.initials: K
authors.lastname: Yamada
authors.forename: Hidenao
authors.initials: H
authors.lastname: Fukuyama
authors.forename: Nobuo
authors.initials: N
authors.lastname: Hashimoto
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002543:Cerebral Hemorrhage / Q000175:diagnosis* / Q000209:etiology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009072:Moyamoya Disease / Q000150:complications*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity