title: Benefit of 3T Diffusion-weighted Imaging in Comparison to Contrast-enhanced MR Imaging for the Evaluation of Disseminated Lesions in Primary Malignant Brain Tumors.
abstract: OBJECTIVE
  We aimed to determine whether 3T diffusion-weighted imaging (DWI) has an additive value relative to contrast-enhanced MR imaging for the detection of disseminated lesions in patients with primary malignant brain tumors.
  
  
  METHODS
  We included consecutive 12 patients with nodular disseminated lesions of primary malignant brain tumors that were confirmed by surgery or follow-up MR imaging. All underwent conventional MR imaging, DWI at b = 1000 and 3000 s/mm2, post-contrast T1-weighted and 3D gradient-echo imaging at 3T. For the largest lesion per person, two radiologists independently evaluated the presence of additional information on DWI compared with postcontrast MR images using a 4-point scoring system. On DW images, one radiologist measured the lesion-to-brain contrast ratio (LBCR).
  
  
  RESULTS
  Compared with postcontrast studies, radiologists 1 and 2, respectively, assigned more apparent lesion conspicuity in 2 (17%) and 1 (8%) DWI at b = 1000 s/mm2and 4 (33%) and 5 (42%) DWI at b = 3000 s/mm2studies. For one of them, the mean score was significantly higher for b = 3000 s/mm2than b = 1000 s/mm2(P < 0.05). Interobserver agreement for DWI at b = 1000 s/mm2and b = 3000 s/mm2was very good (κ = 0.85; 95% CI, 0.63-1.00) and excellent (κ = 0.93; 95% CI, 0.78-1.00), respectively. The mean LBCR was significantly higher for DWI at b = 3000 s/mm2than DWI at b = 1000 s/mm2(P < 0.01).
  
  
  CONCLUSIONS
  In the detection of disseminated lesions in patients with primary malignant brain tumors, 3T DWI has an additive value relative to contrast-enhanced MR imaging. DWI at b = 3000 s/mm2may be more useful than DWI at b = 1000 s/mm2.
authors.affiliation: Department of Radiology, Faculty of Medicine, University of Miyazaki.
authors.forename: Yoshihito
authors.initials: Y
authors.lastname: Kadota
authors.affiliation: Department of Radiology, Faculty of Medicine, University of Miyazaki.
authors.forename: Toshinori
authors.initials: T
authors.lastname: Hirai
authors.affiliation: Department of Neurosurgery, Graduate School of Medical Sciences, Kumamoto University.
authors.forename: Hideo
authors.initials: H
authors.lastname: Nakamura
authors.affiliation: Department of Neurosurgery, Graduate School of Medical Sciences, Kumamoto University.
authors.forename: Keishi
authors.initials: K
authors.lastname: Makino
authors.affiliation: Department of Neurosurgery, Graduate School of Medical Sciences, Kumamoto University.
authors.forename: Shigetoshi
authors.initials: S
authors.lastname: Yano
authors.affiliation: Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University.
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Nishimura
authors.affiliation: Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University.
authors.forename: Machiko
authors.initials: M
authors.lastname: Tateishi
authors.affiliation: Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University.
authors.forename: Minako
authors.initials: M
authors.lastname: Azuma
authors.affiliation: Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University.
authors.forename: Mika
authors.initials: M
authors.lastname: Kitajima
authors.affiliation: Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Yamashita
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001932:Brain Neoplasms / Q000000981:diagnostic imaging*; D002648:Child; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008297:Male; D008875:Middle Aged; D055815:Young Adult
keywords: 3T MRI; diffusion-weighted imaging; dissemination; high-b value