title: Experimental ischemic brain edema: morphological and magnetic resonance imaging findings.
abstract: Magnetic resonance (MR) imaging is a powerful tool for detecting and characterizing ischemic edema, a serious complication of ischemic cerebrovascular disorders. In this article the authors investigate the relationships between MR imaging findings and structural/ultrastructural changes in ischemic brain edema by using various animal models of experimental cerebral ischemia. The authors observed the following: 1) Ischemic edema was detectable by diffusion weighted MR imaging as early as 15 minutes after the onset of vascular occlusion. A decrease in the apparent diffusion coefficient (ADC) corresponded to the early cellular/cytotoxic type of brain edema and the decrease was proportionate to the degree of intracellular water accumulation. 2) Postischemic transient normalization of the ADC after the initial decrease did not signify histological recovery but rather slowly progressing infarction. 3) Histological degradation of postischemic tissue correlated with the decrease in tissue elasticity and the magnetization transfer ratio. 4) Transient cytotoxic edema localized in the substantia nigra preceding neuronal death was detectable on MR images after ipsilateral striatal infarction. Thus, MR imaging is a powerful tool for detecting and characterizing brain edema associated with ischemic stroke.
authors.affiliation: Department of Pathophysiology, Medical Research Institute, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo, Japan. tkuroiwa.nsu@umin.ac.jp
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Kuroiwa
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Miyasaka
authors.forename: Zhao
authors.initials: Z
authors.lastname: Fengyo
authors.forename: Ichiro
authors.initials: I
authors.lastname: Yamada
authors.forename: Makoto
authors.initials: M
authors.lastname: Nakane
authors.forename: Tsukasa
authors.initials: T
authors.lastname: Nagaoka
authors.forename: Akira
authors.initials: A
authors.lastname: Tamura
authors.forename: Kikuo
authors.initials: K
authors.lastname: Ohno
mesh_terms: D000818:Animals; D001921:Brain / Q000473:pathology / Q000648:ultrastructure; D001929:Brain Edema / Q000209:etiology* / Q000473:pathology*; D002545:Brain Ischemia / Q000150:complications*; D002544:Cerebral Infarction / Q000209:etiology / Q000473:pathology; D004058:Diffusion; D038524:Diffusion Magnetic Resonance Imaging; D004195:Disease Models, Animal; D007839:Functional Laterality; D005849:Gerbillinae; D008279:Magnetic Resonance Imaging; D008297:Male; D046529:Microscopy, Electron, Transmission; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors