title: Cerebral blood flow and metabolism associated with cerebral microbleeds in small vessel disease.
abstract: OBJECTIVE
  Cerebral microbleeds (CMBs), probably reflecting microangiopathy, have not yet sufficiently been examined in association with cerebral blood flow (CBF) and metabolism. We investigated the relationships between CMBs, and CBF and metabolism in symptomatic small vessel disease.
  
  
  METHODS
  We enrolled 22 patients with symptomatic small vessel disease without severe stenosis (>50 %) in major cerebral arteries. Volumes of white matter lesions (WMLs) and number of CMBs were assessed on images of fluid-attenuated inversion recovery and gradient-echo T2*-weighted magnetic resonance imaging, respectively. Patients were divided into two groups according to the median number of CMBs (group I <5, n = 10; group II ≥5, n = 12). Parametric images of CBF, cerebral metabolic rate of oxygen (CMRO2), oxygen extraction fraction and cerebral blood volume were estimated using positron emission tomography and (15)O-labeled gases. The functional values in the cortex-subcortex, basal ganglia, and centrum semiovale were compared between the two groups.
  
  
  RESULTS
  Volumes of WMLs of group II were larger than those of group I (median: 38.4; range: 25.1-91.5 mL vs. median: 11.3; range: 4.2-73.4 mL, p = 0.01). In the centrum semiovale, the mean CBF of group II was significantly lower than that of group I (12.6 ± 2.6 vs. 15.6 ± 3.3 mL/100 g/min, p = 0.04). In the other regions, there were no significant differences in either CBF or CMRO2 between the two groups.
  
  
  CONCLUSIONS
  Our study indicated that increases in the number of CMBs with larger volumes of WMLs were associated with cerebral ischemia in the deep white matter in patients with symptomatic small vessel disease.
authors.affiliation: Department of Cerebrovascular Medicine, National Cerebral and Cardiovascular Center, 5-7-1 Fujishiro-dai, Suita, Osaka, 565-8565, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Hashimoto
authors.affiliation: Department of Cerebrovascular Medicine, National Cerebral and Cardiovascular Center, 5-7-1 Fujishiro-dai, Suita, Osaka, 565-8565, Japan. cyokota@ncvc.go.jp.
authors.forename: Chiaki
authors.initials: C
authors.lastname: Yokota
authors.affiliation: Department of Investigative Radiology, National Cerebral and Cardiovascular Center, Suita, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Koshino
authors.affiliation: Department of Cerebrovascular Medicine, National Cerebral and Cardiovascular Center, 5-7-1 Fujishiro-dai, Suita, Osaka, 565-8565, Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Shimomura
authors.affiliation: Department of Cerebrovascular Medicine, National Cerebral and Cardiovascular Center, 5-7-1 Fujishiro-dai, Suita, Osaka, 565-8565, Japan.
authors.forename: Tenyu
authors.initials: T
authors.lastname: Hino
authors.affiliation: Department of Investigative Radiology, National Cerebral and Cardiovascular Center, Suita, Japan.
authors.forename: Tetsuaki
authors.initials: T
authors.lastname: Moriguchi
authors.affiliation: Department of Investigative Radiology, National Cerebral and Cardiovascular Center, Suita, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Hori
authors.affiliation: Department of Cerebrovascular Medicine, National Cerebral and Cardiovascular Center, 5-7-1 Fujishiro-dai, Suita, Osaka, 565-8565, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Uehara
authors.affiliation: Department of Cerebrovascular Medicine, National Cerebral and Cardiovascular Center, 5-7-1 Fujishiro-dai, Suita, Osaka, 565-8565, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Minematsu
authors.affiliation: Department of Investigative Radiology, National Cerebral and Cardiovascular Center, Suita, Japan.
authors.forename: Hidehiro
authors.initials: H
authors.lastname: Iida
authors.affiliation: Department of Cerebrovascular Medicine, National Cerebral and Cardiovascular Center, 5-7-1 Fujishiro-dai, Suita, Osaka, 565-8565, Japan.
authors.forename: Kazunori
authors.initials: K
authors.lastname: Toyoda
mesh_terms: D000368:Aged; D002543:Cerebral Hemorrhage / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000503:physiopathology; D002560:Cerebrovascular Circulation; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D055806:Microvessels / Q000000981:diagnostic imaging / Q000378:metabolism / Q000503:physiopathology*; D012189:Retrospective Studies
keywords: Centrum semiovale; Cerebral blood flow; Cerebral microbleeds; Small vessel disease; White matter lesions