title: Comparison of 3.0- and 1.5-T three-dimensional time-of-flight MR angiography in moyamoya disease: preliminary experience.
abstract: OBJECTIVE
  To prospectively compare 3.0- and 1.5-T three-dimensional (3D) time-of-flight (TOF) magnetic resonance (MR) angiography in patients with moyamoya disease, with special emphasis on the visualization of abnormal netlike vessels (moyamoya vessels).
  
  
  METHODS
  Study protocols were approved by the local ethics committee; written informed consent was obtained from all patients. The study included 24 consecutive patients with moyamoya disease (four male and 20 female patients). Patients ranged in age from 17 to 66 years (mean age, 41 years). Moyamoya disease had been diagnosed in all patients before they were entered into the study. All patients underwent 3D TOF MR angiography at both 3.0 and 1.5 T; imaging examinations were performed within 14 days of each other. Maximum intensity projections (MIPs) obtained with MR angiography performed at both 3.0 and 1.5 T were evaluated by two neuroradiologists; the visualization of moyamoya vessels was graded according to a 4-point scale. For both 3.0- and 1.5-T imaging, the number of high-signal-intensity areas and the summation of cross-sectional areas of high signal intensity on source images obtained at the same level of MR angiography were compared quantitatively by using the Wilcoxon matched-pair signed-rank test.
  
  
  RESULTS
  Moyamoya vessels were better visualized on MIPs obtained with 3.0-T imaging than on MIPs obtained with 1.5-T imaging (P < .001). At the identical level of the source image, 3.0-T imaging depicted more high-signal-intensity areas than did 1.5-T imaging. Wider cross-sectional areas of moyamoya vessels were visualized with 3.0-T imaging than with 1.5-T imaging (P < .001).
  
  
  CONCLUSIONS
  Moyamoya vessels are better depicted with MR angiography at 3.0 T than at 1.5 T.
authors.affiliation: Department of Diagnostic Imaging and Nuclear Medicine, Department of Neurosurgery, and Human Brain Research Center, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawaharacho, Sakyo-ku, Kyoto, 606-8507, Japan.
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Fushimi
authors.forename: Yukio
authors.initials: Y
authors.lastname: Miki
authors.forename: Ken-ichiro
authors.initials: K
authors.lastname: Kikuta
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Okada
authors.forename: Mitsunori
authors.initials: M
authors.lastname: Kanagaki
authors.forename: Akira
authors.initials: A
authors.lastname: Yamamoto
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Nozaki
authors.forename: Nobuo
authors.initials: N
authors.lastname: Hashimoto
authors.forename: Takashi
authors.initials: T
authors.lastname: Hanakawa
authors.forename: Hidenao
authors.initials: H
authors.lastname: Fukuyama
authors.forename: Kaori
authors.initials: K
authors.lastname: Togashi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000379:methods; D008297:Male; D008875:Middle Aged; D009072:Moyamoya Disease / Q000175:diagnosis*; D011446:Prospective Studies