title: In vivo MRI signatures of hippocampal subfield pathology in intractable epilepsy.
abstract: OBJECTIVE
  Our aim is to assess the subfield-specific histopathological correlates of hippocampal volume and intensity changes (T1, T2) as well as diff!usion MRI markers in TLE, and investigate the efficacy of quantitative MRI measures in predicting histopathology in vivo.
  
  
  METHODS
  We correlated in vivo volumetry, T2 signal, quantitative T1 mapping, as well as diffusion MRI parameters with histological features of hippocampal sclerosis in a subfield-specific manner. We made use of on an advanced co-registration pipeline that provided a seamless integration of preoperative 3 T MRI with postoperative histopathological data, on which metrics of cell loss and gliosis were quantitatively assessed in CA1, CA2/3, and CA4/DG.
  
  
  RESULTS
  MRI volumes across all subfields were positively correlated with neuronal density and size. Higher T2 intensity related to increased GFAP fraction in CA1, while quantitative T1 and diffusion MRI parameters showed negative correlations with neuronal density in CA4 and DG. Multiple linear regression analysis revealed that in vivo multiparametric MRI can predict neuronal loss in all the analyzed subfields with up to 90% accuracy.
  
  
  CONCLUSIONS
  Our results, based on an accurate co-registration pipeline and a subfield-specific analysis of MRI and histology, demonstrate the potential of MRI volumetry, diffusion, and quantitative T1 as accurate in vivo biomarkers of hippocampal pathology.
authors.affiliation: Imaging Research Laboratories, Robarts Research Institute, London, Ontario, Canada.|Biomedical Engineering Graduate Program, Western University, London, Ontario, Canada.
authors.forename: Maged
authors.initials: M
authors.lastname: Goubran
authors.affiliation: Neuroimaging of Epilepsy Laboratory, McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada.
authors.forename: Boris C
authors.initials: BC
authors.lastname: Bernhardt
authors.affiliation: Imaging Research Laboratories, Robarts Research Institute, London, Ontario, Canada.|Biomedical Engineering Graduate Program, Western University, London, Ontario, Canada.
authors.forename: Diego
authors.initials: D
authors.lastname: Cantor-Rivera
authors.affiliation: Department of Clinical Neurological Sciences, Epilepsy Program, Western University, London, Ontario, Canada.
authors.forename: Jonathan C
authors.initials: JC
authors.lastname: Lau
authors.affiliation: Imaging Research Laboratories, Robarts Research Institute, London, Ontario, Canada.|Biomedical Engineering Graduate Program, Western University, London, Ontario, Canada.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Blinston
authors.affiliation: Department of Pathology, Division of Neuropathology, London, Ontario, Canada.
authors.forename: Robert R
authors.initials: RR
authors.lastname: Hammond
authors.affiliation: Biomedical Engineering Graduate Program, Western University, London, Ontario, Canada.|Department of Clinical Neurological Sciences, Epilepsy Program, Western University, London, Ontario, Canada.|Department of Medical Biophysics, Western University, London, Ontario, Canada.
authors.forename: Sandrine
authors.initials: S
authors.lastname: de Ribaupierre
authors.affiliation: Department of Clinical Neurological Sciences, Epilepsy Program, Western University, London, Ontario, Canada.
authors.forename: Jorge G
authors.initials: JG
authors.lastname: Burneo
authors.affiliation: Department of Clinical Neurological Sciences, Epilepsy Program, Western University, London, Ontario, Canada.|Department of Medical Biophysics, Western University, London, Ontario, Canada.|Department of Medical Imaging, Western University, London, Ontario, Canada.
authors.forename: Seyed M
authors.initials: SM
authors.lastname: Mirsattari
authors.affiliation: Department of Clinical Neurological Sciences, Epilepsy Program, Western University, London, Ontario, Canada.
authors.forename: David A
authors.initials: DA
authors.lastname: Steven
authors.affiliation: Department of Clinical Neurological Sciences, Epilepsy Program, Western University, London, Ontario, Canada.
authors.forename: Andrew G
authors.initials: AG
authors.lastname: Parrent
authors.affiliation: Neuroimaging of Epilepsy Laboratory, McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada.
authors.forename: Andrea
authors.initials: A
authors.lastname: Bernasconi
authors.affiliation: Neuroimaging of Epilepsy Laboratory, McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada.
authors.forename: Neda
authors.initials: N
authors.lastname: Bernasconi
authors.affiliation: Imaging Research Laboratories, Robarts Research Institute, London, Ontario, Canada.|Biomedical Engineering Graduate Program, Western University, London, Ontario, Canada.|Department of Medical Biophysics, Western University, London, Ontario, Canada.
authors.forename: Terry M
authors.initials: TM
authors.lastname: Peters
authors.affiliation: Department of Medical Biophysics, Western University, London, Ontario, Canada.|Department of Medical Imaging, Western University, London, Ontario, Canada.
authors.forename: Ali R
authors.initials: AR
authors.lastname: Khan
mesh_terms: D000328:Adult; D002452:Cell Count; D015331:Cohort Studies; D056324:Diffusion Tensor Imaging; D000069279:Drug Resistant Epilepsy / Q000473:pathology* / Q000601:surgery; D005260:Female; D006624:Hippocampus / Q000473:pathology* / Q000601:surgery; D006801:Humans; D007091:Image Processing, Computer-Assisted; D016014:Linear Models; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009474:Neurons / Q000473:pathology; D009929:Organ Size; D015203:Reproducibility of Results; D012598:Sclerosis; D055815:Young Adult
keywords: DTI; MRI; hippocampal sclerosis; hippocampal subfields; histology; temporal lobe epilepsy; volumetry