title: Intralesional Patterns of MRI ADC Maps Predict Outcome in Experimental Stroke.
abstract: BACKGROUND
  After acute ischemia, the tissue that is at risk of infarction can be detected by perfusion-weighted imaging/diffusion-weighted imaging (PWI/DWI) mismatch but the time that is needed to process PWI limits its use. As DWI is highly sensitive to acute ischemic tissue damage, we hypothesized that different ADC patterns represent areas with a different potential for recovery.
  
  
  METHODS
  In a model of permanent middle cerebral artery occlusion (pMCAO), Sprague-Dawley rats were randomly distributed to sham surgery and pMCAO. We further separated the pMCAO group according to intralesional ADC pattern (homogeneous or heterogeneous). At 24 h after ischemia induction, we analyzed lesion size, functional outcome, cell death expression, and brain protection markers including ROS enzyme NOX-4. MRI included DWI (ADC maps), DTI (tractography), and PWI (CBF, CBV and MTT).
  
  
  RESULTS
  The lesion size was similar in pMCAO rats. Animals with a heterogeneous pattern in ADC maps showed better functional outcome in Rotarod test (p = 0.032), less expression of cell death (p = 0.014) and NOX-4 (p = 0.0063), higher intralesional CBF (p = 0.0026) and larger PWI/DWI mismatch (p = 0.007).
  
  
  CONCLUSIONS
  In a rodent model for ischemic stroke, intralesional heterogeneity in ADC maps was related to better functional outcome in lesions of similar size and interval after pMCAO. DWI ADC maps may assist in the early identification of ischemic tissue with an increased potential for recovery as higher expression of acute protection markers, lower expression of cell death, increased PWI/DWI mismatch, and higher intralesional CBF were present in animals with a heterogeneous ADC pattern.
authors.affiliation: Department of Neurology and Stroke Centre, Neuroscience and Cerebrovascular Research Laboratory, La Paz University Hospital, Neuroscience Area of IdiPAZ (Health Research Institute), Autónoma University of Madrid, Madrid, Spain.
authors.forename: Isabel
authors.initials: I
authors.lastname: Lestro Henriques
authors.forename: María
authors.initials: M
authors.lastname: Gutiérrez-Fernández
authors.forename: Berta
authors.initials: B
authors.lastname: Rodríguez-Frutos
authors.forename: Jaime
authors.initials: J
authors.lastname: Ramos-Cejudo
authors.forename: Laura
authors.initials: L
authors.lastname: Otero-Ortega
authors.forename: Teresa
authors.initials: T
authors.lastname: Navarro Hernanz
authors.forename: Sebastián
authors.initials: S
authors.lastname: Cerdán
authors.forename: José M
authors.initials: JM
authors.lastname: Ferro
authors.forename: Exuperio
authors.initials: E
authors.lastname: Díez-Tejedor
mesh_terms: D000375:Aging; D000818:Animals; D002545:Brain Ischemia / Q000473:pathology*; D002560:Cerebrovascular Circulation / Q000502:physiology; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods; D004195:Disease Models, Animal; D020244:Infarction, Middle Cerebral Artery / Q000473:pathology*; D008297:Male; D055420:Perfusion Imaging / Q000379:methods; D017207:Rats, Sprague-Dawley; D020521:Stroke / Q000473:pathology* / Q000503:physiopathology