title: Detecting deoxyhemoglobin in spinal cord vasculature of the experimental autoimmune encephalomyelitis mouse model of multiple sclerosis using susceptibility MRI and hyperoxygenation.
abstract: Susceptibility-weighted imaging (SWI) detects hypointensities due to iron deposition and deoxyhemoglobin. Previously it was shown that SWI detects hypointensities in the experimental autoimmune encephalomyelitis (EAE) model of multiple sclerosis (MS), most of which are due to intravascular deoxyhemoglobin, with a small proportion being due to iron deposition in the central nervous system parenchyma and demyelination. However, animals had to be sacrificed to differentiate these two types of lesions which is impractical for time course studies or for human application. Here, we proposed altering the inspired oxygen concentration during imaging to identify deoxyhemoglobin-based hypointensities in vivo. SWI was performed on lumbar spinal cords of naive control and EAE mice using 30% O2 then 100% O2. Some mice were imaged using 30% O2, 100% O2 and after perfusion. Most SWI-visible hypointensities seen with 30% O2 changed in appearance upon administration of 100% O2, and were not visible after perfusion. That hypointensities changed with hyperoxygenation indicates that they were caused by deoxyhemoglobin. We show that increasing the inspired oxygen concentration identifies deoxyhemoglobin-based hypointensities in vivo. This could be applied in future studies to investigate the contribution of vascular-based hypointensities with SWI in EAE and MS over time.
authors.affiliation: Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada; Department of Radiology, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Nabeela
authors.initials: N
authors.lastname: Nathoo
authors.affiliation: Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada; Department of Clinical Neurosciences and Oncology, University of Calgary, Calgary, Alberta, Canada.
authors.forename: James A
authors.initials: JA
authors.lastname: Rogers
authors.affiliation: Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada; Department of Clinical Neurosciences and Oncology, University of Calgary, Calgary, Alberta, Canada.
authors.forename: V Wee
authors.initials: VW
authors.lastname: Yong
authors.affiliation: Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada; Department of Radiology, University of Calgary, Calgary, Alberta, Canada; Experimental Imaging Centre, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Jeff F
authors.initials: JF
authors.lastname: Dunn
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004681:Encephalomyelitis, Autoimmune, Experimental / Q000175:diagnosis* / Q000378:metabolism*; D005260:Female; D006454:Hemoglobins / Q000378:metabolism*; D006801:Humans; D008279:Magnetic Resonance Imaging; D051379:Mice; D009103:Multiple Sclerosis / Q000175:diagnosis / Q000378:metabolism; D010101:Oxygen Consumption; D013116:Spinal Cord / Q000098:blood supply* / Q000378:metabolism*
chemical_list: D006454:Hemoglobins; C100003:deoxyhemoglobin