title: Is it possible to define salvageable ischemic penumbra using semiquantitative rCBF levels derived from MR perfusion-weighted imaging?
abstract: BACKGROUND
  The purpose of this study was to test if magnetic resonance (MR) perfusion-weighted imaging (PWI) can reliably characterize the ischemic penumbra.
  
  
  METHODS
  Sixteen patients with nonlacunar ischemic stroke who were scanned within 24 h after onset of symptoms were selected for the study. In previous studies, the level of regional cerebral blood flow (rCBF) in the normal white matter of the contralateral hemisphere was defined as 22 ml/100 g/min. We used this level as a standard of reference. We hypothesized that rCBF below this level would be amenable to infarct. The lesion-to-white matter ratios of rCBF were measured in the regions of ischemic core ("Core"), infarcted penumbra ("Growth"), salvaged penumbra ("Reversed"), and contralateral normal cortex ("Normal").
  
  
  RESULTS
  The rCBF of "Growth" and "Reversed" areas showed substantial overlap, which hampered the delineation of areas that would become infarcted.
  
  
  CONCLUSIONS
  The semiquantitative rCBF derived from MR PWI may not accurately characterize the ischemic penumbra.
authors.affiliation: Department of Radiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto City, Kyoto, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Akazawa
authors.forename: Kei
authors.initials: K
authors.lastname: Yamada
authors.forename: Shigenori
authors.initials: S
authors.lastname: Matsushima
authors.forename: Takao
authors.initials: T
authors.lastname: Kubota
authors.forename: Yoshinari
authors.initials: Y
authors.lastname: Nagakane
authors.forename: Nagato
authors.initials: N
authors.lastname: Kuriyama
authors.forename: Masanori
authors.initials: M
authors.lastname: Nakagawa
authors.forename: Tsunehiko
authors.initials: T
authors.lastname: Nishimura
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001810:Blood Volume / Q000502:physiology*; D002545:Brain Ischemia / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D016208:Databases, Factual; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012307:Risk Factors; D020521:Stroke / Q000209:etiology / Q000473:pathology / Q000503:physiopathology*