title: Diffusion- and perfusion-weighted MRI response to thrombolysis in stroke.
abstract: Diffusion- and perfusion-weighted magnetic resonance imaging provides important pathophysiological information in acute brain ischemia. We performed a prospective study in 19 sub-6-hour stroke patients using serial diffusion- and perfusion-weighted imaging before intravenous thrombolysis, with repeat studies, both subacutely and at outcome. For comparison of ischemic lesion evolution and clinical outcome, we used a historical control group of 21 sub-6-hour ischemic stroke patients studied serially with diffusion- and perfusion-weighted imaging. The two groups were well matched for the baseline National Institutes of Health Stroke Scale and magnetic resonance parameters. Perfusion-weighted imaging-diffusion-weighted imaging mismatch was present in 16 of 19 patients treated with tissue plasminogen activator, and 16 of 21 controls. Perfusion-weighted imaging-diffusion-weighted imaging mismatch patients treated with tissue plaminogen activator had higher recanalization rates and enhanced reperfusion at day 3 (81% vs 47% in controls), and a greater proportion of severely hypoperfused acute mismatch tissue not progressing to infarction (82% vs -25% in controls). Despite similar baseline diffusion-weighted imaging lesions, infarct expansion was less in the recombinant tissue plaminogen activator group (14cm(3) vs 56cm(3) in controls). The positive effect of thrombolysis on lesion growth in mismatch patients translated into a greater improvement in baseline to outcome National Institutes of Health Stroke Scale in the group treated with recombinant tissue plaminogen activator, and a significantly larger proportion of patients treated with recombinant tissue plaminogen activator having a clinically meaningful improvement in National Institutes of Health Stroke Scale of > or = 7 points. The natural evolution of acute perfusion-weighted imaging-diffusion-weighted imaging mismatch tissue may be altered by thrombolysis, with improved stroke outcome. This has implications for the use of diffusion- and perfusion-weighted imaging in selecting and monitoring patients for thrombolytic therapy.
authors.affiliation: Royal Melbourne Hospital Echoplanar Imaging Stroke Study Group, Melbourne, Australia.
authors.forename: Mark W
authors.initials: MW
authors.lastname: Parsons
authors.forename: P Alan
authors.initials: PA
authors.lastname: Barber
authors.forename: Jonathon
authors.initials: J
authors.lastname: Chalk
authors.forename: David G
authors.initials: DG
authors.lastname: Darby
authors.forename: Stephen
authors.initials: S
authors.lastname: Rose
authors.forename: Patricia M
authors.initials: PM
authors.lastname: Desmond
authors.forename: Richard P
authors.initials: RP
authors.lastname: Gerraty
authors.forename: Brian M
authors.initials: BM
authors.lastname: Tress
authors.forename: Peter M
authors.initials: PM
authors.lastname: Wright
authors.forename: Geoffrey A
authors.initials: GA
authors.lastname: Donnan
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Davis
mesh_terms: D000208:Acute Disease; D000368:Aged; D000369:Aged, 80 and over; D002545:Brain Ischemia / Q000175:diagnosis / Q000188:drug therapy; D005260:Female; D005343:Fibrinolytic Agents / Q000627:therapeutic use*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D020521:Stroke / Q000175:diagnosis* / Q000188:drug therapy*; D015912:Thrombolytic Therapy; D010959:Tissue Plasminogen Activator / Q000627:therapeutic use*; D016896:Treatment Outcome
chemical_list: D005343:Fibrinolytic Agents; D010959:Tissue Plasminogen Activator