title: Correlation of perfusion- and diffusion-weighted MRI with NIHSS score in acute (<6.5 hour) ischemic stroke.
abstract: BACKGROUND
  Diffusion-weighted (DWI) and perfusion-weighted (PWI) MRI are powerful new techniques for the assessment of acute cerebral ischemia. However, quantitative data comparing the severity of clinical neurologic deficit with the results of DWI or PWI in the earliest phases of stroke are scarce. Such information is vital if MRI is potentially to be used as an objective adjunctive measure of stroke severity and outcome.
  
  
  OBJECTIVE
  The authors compared initial DWI and PWI lesion volumes with subsequent 24-hour neurologic deficit as determined by National Institutes of Health Stroke Scale (NIHSS) score in acute stroke patients. Initial DWI and PWI volumes were also compared with T2W MRI lesion volume at 1 week to assess the accuracy of these MRI techniques for the detection of acute cerebral ischemia.
  
  
  METHODS
  Patients with stroke underwent MRI scanning within 6.5 hours of symptom onset. Lesion volumes on DWI and PWI were measured and compared with 24-hour NIHSS score. Initial DWI and PWI volumes were also compared with T2W lesion size at 1 week.
  
  
  RESULTS
  There was a high correlation between 24-hour NIHSS score and lesion volume as determined by PWI (r = 0.96, p < 0.001) or DWI (r = 0.67, p = 0.03). A similar high correlation was seen between T2W stroke size at 7 days and initial DWI and PWI lesion size (r = 0.99, p < 0.00001).
  
  
  CONCLUSIONS
  Both DWI and PWI are highly correlated with severity of neurologic deficit by 24-hour NIHSS score. These findings may have substantial implications for the use of MRI scanning in the assessment and management of acute stroke patients.
authors.affiliation: Stanford Stroke Center, Department of Neurology and Neurological Sciences, Stanford University Medical Center, Palo Alto, CA 94304, USA.
authors.forename: D C
authors.initials: DC
authors.lastname: Tong
authors.forename: M A
authors.initials: MA
authors.lastname: Yenari
authors.forename: G W
authors.initials: GW
authors.lastname: Albers
authors.forename: M
authors.initials: M
authors.lastname: O'Brien
authors.forename: M P
authors.initials: MP
authors.lastname: Marks
authors.forename: M E
authors.initials: ME
authors.lastname: Moseley
mesh_terms: D000208:Acute Disease; D000368:Aged; D002545:Brain Ischemia / Q000150:complications / Q000175:diagnosis*; D002544:Cerebral Infarction / Q000175:diagnosis / Q000209:etiology; D002560:Cerebrovascular Circulation; D002561:Cerebrovascular Disorders / Q000175:diagnosis* / Q000209:etiology; D017352:Echo-Planar Imaging / Q000379:methods*; D005260:Female; D005682:Gadolinium; D006801:Humans; D008297:Male; D013997:Time Factors
chemical_list: D005682:Gadolinium