title: Moment analysis of microflow histogram in focal ischemic lesion to evaluate microvascular derangement after small pial arterial occlusion in rats.
abstract: The authors' high-spatial-resolution optical method was used to examine microvascular derangement in a focal cerebral cortex lesion in 12 Sprague-Dawley rats anesthetized with alpha-chloralose-urethane. A pial artery (approximately 40- to 50 microm diameter) was occluded by laser-beam cauterization (n = 6). Diluted carbon black suspension was injected into the internal carotid artery, and images in a 2-mm x 2-mm region of interest during tissue dye-dilution were recorded. Sequential frames were analyzed with Matlab software to evaluate blood distribution and mean transit time, affording a two-dimensional microflow map and histogram with first, second, third, and fourth moments. In the early phase of ischemia, blood distribution and average flow decreased (both P < 0.01), and the second moment (microflow heterogeneity) and third moment (skew to the left owing to increase in low-flow components) increased (P < 0.05 and P < 0.01, respectively). At approximately 2 hours, blood distribution decreased further in 3 cases, apparently because capillary stasis prevented carbon black filling. However, average microflow unexpectedly increased in 4 of 5 rats, presumably due to exclusion of unperfused (low flow at the earlier stage) channels from the calculation. The authors conclude that flow in ischemic tissue is quite heterogeneous and that an averaged flow value tends to smear important information about ischemic microvascular derangement.
authors.affiliation: Department of Neurology, Saitama Municipal Hospital, Saitama-city, Saitama, Japan. y-tomita@sc.itc.keio.ac.jp
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Tomita
authors.forename: Minoru
authors.initials: M
authors.lastname: Tomita
authors.forename: Istvan
authors.initials: I
authors.lastname: Schiszler
authors.forename: Takahiro
authors.initials: T
authors.lastname: Amano
authors.forename: Norio
authors.initials: N
authors.lastname: Tanahashi
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kobari
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Takeda
authors.forename: Manabu
authors.initials: M
authors.lastname: Ohtomo
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Fukuuchi
mesh_terms: D000818:Animals; D001157:Arterial Occlusive Diseases / Q000503:physiopathology; D002545:Brain Ischemia / Q000503:physiopathology*; D002343:Carotid Artery, Internal; D002560:Cerebrovascular Circulation / Q000502:physiology*; D004396:Coloring Agents / Q000493:pharmacokinetics; D017075:Laser Coagulation; D008297:Male; D008833:Microcirculation / Q000502:physiology; D010841:Pia Mater / Q000098:blood supply*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D004396:Coloring Agents