title: High b-value diffusion-weighted imaging: a sensitive method to reveal white matter differences in schizophrenia.
abstract: Over the last 10 years, diffusion-weighted imaging (DWI) has become an important tool to investigate white matter (WM) anomalies in schizophrenia. Despite technological improvement and the exponential use of this technique, discrepancies remain and little is known about optimal parameters to apply for diffusion weighting during image acquisition. Specifically, high b-value diffusion-weighted imaging known to be more sensitive to slow diffusion is not widely used, even though subtle myelin alterations as thought to happen in schizophrenia are likely to affect slow-diffusing protons. Schizophrenia patients and healthy controls were scanned with a high b-value (4000 s/mm(2)) protocol. Apparent diffusion coefficient (ADC) measures turned out to be very sensitive in detecting differences between schizophrenia patients and healthy volunteers even in a relatively small sample. We speculate that this is related to the sensitivity of high b-value imaging to the slow-diffusing compartment believed to reflect mainly the intra-axonal and myelin bound water pool. We also compared these results to a low b-value imaging experiment performed on the same population in the same scanning session. Even though the acquisition protocols are not strictly comparable, we noticed important differences in sensitivities in the favor of high b-value imaging, warranting further exploration.
authors.affiliation: Department of Psychiatry, University Hospital Center and University of Lausanne, Lausanne, Switzerland. Philipp.Baumann@chuv.ch
authors.forename: Philipp Sebastian
authors.initials: PS
authors.lastname: Baumann
authors.forename: Leila
authors.initials: L
authors.lastname: Cammoun
authors.forename: Philippe
authors.initials: P
authors.lastname: Conus
authors.forename: Kim Quang
authors.initials: KQ
authors.lastname: Do
authors.forename: Pierre
authors.initials: P
authors.lastname: Marquet
authors.forename: Djalel
authors.initials: D
authors.lastname: Meskaldji
authors.forename: Reto
authors.initials: R
authors.lastname: Meuli
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Thiran
authors.forename: Patric
authors.initials: P
authors.lastname: Hagmann
mesh_terms: D000328:Adult; D001921:Brain / Q000473:pathology*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D004292:Dominance, Cerebral / Q000502:physiology; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D056784:Leukoencephalopathies / Q000175:diagnosis* / Q000473:pathology; D008297:Male; D009413:Nerve Fibers, Myelinated / Q000473:pathology*; D011569:Psychiatric Status Rating Scales; D012016:Reference Values; D012559:Schizophrenia / Q000175:diagnosis* / Q000473:pathology; D012565:Schizophrenic Psychology; D012680:Sensitivity and Specificity