title: A multi-contrast MRI study of microstructural brain damage in patients with mild cognitive impairment.
abstract: OBJECTIVE
  The aim of this study was to investigate pathological mechanisms underlying brain tissue alterations in mild cognitive impairment (MCI) using multi-contrast 3 T magnetic resonance imaging (MRI).
  
  
  METHODS
  Forty-two MCI patients and 77 healthy controls (HC) underwent T1/T2* relaxometry as well as Magnetization Transfer (MT) MRI. Between-groups comparisons in MRI metrics were performed using permutation-based tests. Using MRI data, a generalized linear model (GLM) was computed to predict clinical performance and a support-vector machine (SVM) classification was used to classify MCI and HC subjects.
  
  
  RESULTS
  Multi-parametric MRI data showed microstructural brain alterations in MCI patients vs HC that might be interpreted as: (i) a broad loss of myelin/cellular proteins and tissue microstructure in the hippocampus (p ≤ 0.01) and global white matter (p < 0.05); and (ii) iron accumulation in the pallidus nucleus (p ≤ 0.05). MRI metrics accurately predicted memory and executive performances in patients (p ≤ 0.005). SVM classification reached an accuracy of 75% to separate MCI and HC, and performed best using both volumes and T1/T2*/MT metrics.
  
  
  CONCLUSIONS
  Multi-contrast MRI appears to be a promising approach to infer pathophysiological mechanisms leading to brain tissue alterations in MCI. Likewise, parametric MRI data provide powerful correlates of cognitive deficits and improve automatic disease classification based on morphometric features.
authors.affiliation: Department of Clinical Neurosciences, CHUV, Lausanne, VD, Switzerland ; Advanced Clinical Imaging Technology, EPFL, Lausanne, VD, Switzerland.
authors.forename: C
authors.initials: C
authors.lastname: Granziera
authors.affiliation: STI IEL LTS5, EPFL, Lausanne, VD, Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: Daducci
authors.affiliation: Service of Old-Age Psychiatry, Department of Psychiatry, CHUV, Lausanne, VD, Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: Donati
authors.affiliation: Advanced Clinical Imaging Technology, EPFL, Lausanne, VD, Switzerland.
authors.forename: G
authors.initials: G
authors.lastname: Bonnier
authors.affiliation: Advanced Clinical Imaging Technology, EPFL, Lausanne, VD, Switzerland.
authors.forename: D
authors.initials: D
authors.lastname: Romascano
authors.affiliation: Advanced Clinical Imaging Technology, EPFL, Lausanne, VD, Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: Roche
authors.affiliation: Department of Radiology, CHUV, Lausanne, VD, Switzerland ; Signal Processing Core, Center for Biomedical Imaging, CHUV, Lausanne, VD, Switzerland.
authors.forename: M
authors.initials: M
authors.lastname: Bach Cuadra
authors.affiliation: Advanced Clinical Imaging Technology, EPFL, Lausanne, VD, Switzerland.
authors.forename: D
authors.initials: D
authors.lastname: Schmitter
authors.affiliation: Department of Psychiatry and Psychotherapy, Section of Gerontopsychiatry, Department of Neurology, University Medical Center, Freiburg, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Klöppel
authors.affiliation: Department of Radiology, CHUV, Lausanne, VD, Switzerland.
authors.forename: R
authors.initials: R
authors.lastname: Meuli
authors.affiliation: Service of Old-Age Psychiatry, Department of Psychiatry, CHUV, Lausanne, VD, Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: von Gunten
authors.affiliation: Advanced Clinical Imaging Technology, EPFL, Lausanne, VD, Switzerland ; Heathcare IM S AW, Siemens Schweiz AG, Renens, VD, Switzerland.
authors.forename: G
authors.initials: G
authors.lastname: Krueger
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D060825:Cognitive Dysfunction / Q000473:pathology*; D005260:Female; D005917:Globus Pallidus / Q000378:metabolism*; D006624:Hippocampus / Q000473:pathology*; D006801:Humans; D007501:Iron / Q000378:metabolism*; D008279:Magnetic Resonance Imaging / Q000379:methods* / Q000592:standards; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D066127:White Matter / Q000473:pathology*
chemical_list: D007501:Iron
keywords: Magnetization transfer imaging; Mild cognitive impairment; Multi-contrast MRI; Quantitative MRI; Relaxometry