title: Hemodynamic changes following wingspan stent placement--a quantitative magnetic resonance angiography study.
abstract: BACKGROUND
  Quantitative magnetic resonance angiography (QMRA) is a noninvasive imaging modality that provides anatomic and physiologic measurements of arteries. We used QMRA to assess hemodynamic changes following Wingspan stent placement for intracranial stenosis.
  
  
  METHODS
  We reviewed patients treated with Wingspan stents for intracranial stenosis who had baseline and follow-up QMRA data. We compared volumetric flow rates (VFRs) (mL/minute) pre- and poststenting using paired t-tests. P<.05 was considered significant.
  
  
  RESULTS
  Among 9 patients (mean age 65.8 years, mean 71% degree of stenosis), lesions were located in the supraclinoid internal carotid arteries in 3, middle cerebral arteries in 3, and intracranial vertebrobasilar arteries in 3. VFR and degree of stenosis were moderately correlated (r=-.670, P=.002). The mean VFR in the stenotic artery increased from 81.2 mL/minute to 133.3 mL/minute (P=.020) or by 64.2% after stenting. Total cerebral blood flow, flow in nonstented vessels, and collateral flow in circle of Willis vessels did not significantly change.
  
  
  CONCLUSIONS
  We found that QMRA is a promising noninvasive method for the measurement of cerebral hemodynamics following intracranial Wingspan stent placement. Larger prospective studies are needed to confirm our findings.
authors.affiliation: Department of Neurological Sciences, Radiology and Neurosurgery, Rush University Medical Center, Chicago, IL 60612, USA. shyam_prabhakaran@rush.edu
authors.forename: Shyam
authors.initials: S
authors.lastname: Prabhakaran
authors.forename: Kalani R
authors.initials: KR
authors.lastname: Wells
authors.forename: Miral D
authors.initials: MD
authors.lastname: Jhaveri
authors.forename: Demetrius K
authors.initials: DK
authors.lastname: Lopes
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001488:Basilar Artery / Q000473:pathology; D001783:Blood Flow Velocity; D003251:Constriction, Pathologic / Q000473:pathology; D005260:Female; D006439:Hemodynamics; D006801:Humans; D002537:Intracranial Arteriosclerosis / Q000473:pathology* / Q000628:therapy*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D020768:Middle Cerebral Artery / Q000473:pathology; D012189:Retrospective Studies; D015607:Stents; D014711:Vertebral Artery / Q000473:pathology