title: Validation of quantitative susceptibility mapping with Perls' iron staining for subcortical gray matter.
abstract: Quantitative susceptibility mapping (QSM) measures bulk susceptibilities in the brain, which can arise from many sources. In iron-rich subcortical gray matter (GM), non-heme iron is a dominant susceptibility source. We evaluated the use of QSM for iron mapping in subcortical GM by direct comparison to tissue iron staining. We performed in situ or in vivo QSM at 4.7 T combined with Perls' ferric iron staining on the corresponding extracted subcortical GM regions. This histochemical process enabled examination of ferric iron in complete slices that could be related to susceptibility measurements. Correlation analyses were performed on an individual-by-individual basis and high linear correlations between susceptibility and Perls' iron stain were found for the three multiple sclerosis (MS) subjects studied (R(2) = 0.75, 0.62, 0.86). In addition, high linear correlations between susceptibility and transverse relaxation rate (R2*) were found (R(2) = 0.88, 0.88, 0.87) which matched in vivo healthy subjects (R(2) = 0.87). This work validates the accuracy of QSM for brain iron mapping and also confirms ferric iron as the dominant susceptibility source in subcortical GM, by demonstrating high linear correlation of QSM to Perls' ferric iron staining.
authors.affiliation: Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada, T6G 2V2.
authors.forename: Hongfu
authors.initials: H
authors.lastname: Sun
authors.affiliation: Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada, T6G 2V2.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Walsh
authors.affiliation: Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada, T6G 2V2.
authors.forename: R Marc
authors.initials: RM
authors.lastname: Lebel
authors.affiliation: Division of Neurology, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada, T6G 2G3.
authors.forename: Gregg
authors.initials: G
authors.lastname: Blevins
authors.affiliation: Division of Neurology, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada, T6G 2G3.
authors.forename: Ingrid
authors.initials: I
authors.lastname: Catz
authors.affiliation: Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Alberta, Canada, T6G 2B7.
authors.forename: Jian-Qiang
authors.initials: JQ
authors.lastname: Lu
authors.affiliation: Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Alberta, Canada, T6G 2B7.
authors.forename: Edward S
authors.initials: ES
authors.lastname: Johnson
authors.affiliation: Department of Radiology and Diagnostic Imaging, University of Alberta, Edmonton, Alberta, Canada, T6G 2B7.
authors.forename: Derek J
authors.initials: DJ
authors.lastname: Emery
authors.affiliation: Division of Neurology, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada, T6G 2G3.
authors.forename: Kenneth G
authors.initials: KG
authors.lastname: Warren
authors.affiliation: Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada, T6G 2V2. Electronic address: wilman@ualberta.ca.
authors.forename: Alan H
authors.initials: AH
authors.lastname: Wilman
mesh_terms: D001923:Brain Chemistry; D066128:Gray Matter / Q000737:chemistry / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007501:Iron / Q000032:analysis / Q000378:metabolism*; D060328:Magnetic Phenomena; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000378:metabolism / Q000473:pathology
chemical_list: D007501:Iron
keywords: Brain iron; Perls' iron stain; Postmortem imaging; Quantitative susceptibility mapping; R2* mapping; Subcortical gray matter