title: Leptomeningeal enhancement on magnetic resonance imaging as a predictor of hemodynamic insufficiency.
abstract: OBJECTIVE
  The objective of this study was to evaluate the value of leptomeningeal enhancement on magnetic resonance imaging in relation to relative cerebral blood flow (rCBF) and cerebrovascular reserve.
  
  
  METHODS
  A retrospective analysis was performed for 31 patients with internal carotid artery or proximal middle cerebral artery occlusion without primary collateral flow, who underwent enhanced T1-weighted magnetic resonance imaging and acetazolamide-challenged perfusion computed tomography. They were graded into 3 groups in leptomeningeal enhancement on T1-weighted imaging. The rCBF and the percentage change of cerebral blood flow were obtained in the ipsilateral middle cerebral artery territory.
  
  
  RESULTS
  The mean percentage changes of CBF were -13.7%, 6.9%, and 23.8% in prominent (n = 11), mild (n = 11), and equivalent (n = 9) increased enhancements, respectively. The degree of leptomeningeal enhancement was significantly reverse-correlated with percentage change of CBF (P < 0.001), whereas the rCBFs were not significantly different.
  
  
  CONCLUSIONS
  The reverse correlation between leptomeningeal enhancement and cerebrovascular reserve suggests that increased enhancement may indicate impaired primary collaterals and hemodynamic insufficiency. Therefore, leptomeningeal enhancement degree can be used as an indicator of hemodynamic state in stroke.
authors.affiliation: From the *Department of Radiology, Ansan Hospital, Korea University College of Medicine; †Department of Neurosurgery, Naeun Hospital, Anyang-si, Gyeonggi-do; ‡Department of Radiology, Guro Hospital, Korea University College of Medicine, Seoul; and §Department of Neurology, Ansan Hospital, Korea University College of Medicine, Ansan-si, Gyeonggi-do, Republic of Korea.
authors.forename: Doran
authors.initials: D
authors.lastname: Hong
authors.forename: Hyung Suk
authors.initials: HS
authors.lastname: Seo
authors.forename: Young Hen
authors.initials: YH
authors.lastname: Lee
authors.forename: Ki Joon
authors.initials: KJ
authors.lastname: Kim
authors.forename: Sang-Il
authors.initials: SI
authors.lastname: Suh
authors.forename: Jin-Man
authors.initials: JM
authors.lastname: Jung
mesh_terms: D000328:Adult; D000368:Aged; D001783:Blood Flow Velocity; D002539:Cerebral Arterial Diseases / Q000473:pathology* / Q000503:physiopathology*; D002560:Cerebrovascular Circulation; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008578:Meninges / Q000473:pathology* / Q000503:physiopathology*; D008875:Middle Aged; D011379:Prognosis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity