title: Moyamoya disease: evaluation with diffusion-weighted and perfusion echo-planar MR imaging.
abstract: OBJECTIVE
  To determine the clinical efficacy of diffusion-weighted and perfusion echo-planar magnetic resonance (MR) imaging in the evaluation of moyamoya disease.
  
  
  METHODS
  Seventeen patients with moyamoya disease were examined prospectively with diffusion-weighted and perfusion echo-planar MR imaging and conventional angiography. The change in the effective transverse relaxation rate (delta R2*) peak value, delta R2* peak time, and delta R2* integral were calculated to assess regional cerebral perfusion. The MR images were compared with angiographic images.
  
  
  RESULTS
  Of the 34 posterior cerebral arteries (PCAs) of the 17 patients, 14 PCAs (41%) in 11 patients showed stenosis or occlusion. The delta R2* peak value ratio in the cerebral hemispheres decreased significantly, and the delta R2* peak time ratio increased significantly, with PCA stenosis and occlusion. However, no correlation was apparent between perfusion and extent of the stenotic or occlusive lesions of the internal carotid artery bifurcation. The frequency of cerebral infarctions was significantly increased in patients with stenotic or occlusive PCA lesions. For three acute infarctions, a decrease in the apparent diffusion coefficient was significantly correlated with a decrease in the delta R2* peak value, an increase in the delta R2* peak time, and a decrease in the delta R2* integral.
  
  
  CONCLUSIONS
  Regional cerebral perfusion in moyamoya disease is decreased and delayed with PCA stenosis, with greater decrease and delay with PCA occlusion. Diffusion-weighted and perfusion imaging are useful for evaluating cerebral ischemia in moyamoya disease.
authors.affiliation: Department of Radiology, Faculty of Medicine, Tokyo Medical and Dental University, Japan. yamada.crad@med.tmd.ac.jp
authors.forename: I
authors.initials: I
authors.lastname: Yamada
authors.forename: Y
authors.initials: Y
authors.lastname: Himeno
authors.forename: T
authors.initials: T
authors.lastname: Nagaoka
authors.forename: H
authors.initials: H
authors.lastname: Akimoto
authors.forename: Y
authors.initials: Y
authors.lastname: Matsushima
authors.forename: T
authors.initials: T
authors.lastname: Kuroiwa
authors.forename: H
authors.initials: H
authors.lastname: Shibuya
mesh_terms: D000328:Adult; D001921:Brain / Q000098:blood supply / Q000473:pathology; D002545:Brain Ischemia / Q000175:diagnosis; D002533:Cerebral Angiography; D003287:Contrast Media; D017352:Echo-Planar Imaging / Q000379:methods*; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D009072:Moyamoya Disease / Q000175:diagnosis*; D011446:Prospective Studies
chemical_list: D003287:Contrast Media; C064925:gadodiamide; D019786:Gadolinium DTPA