Article Text

Download PDFPDF
Magnetic resonance perfusion diffusion mismatch and thrombolysis in acute ischaemic stroke: a systematic review of the evidence to date
  1. I Kane1,
  2. P Sandercock2,
  3. J Wardlaw2
  1. 1Department of General Medicine, St Richard’s Hospital, Chichester, UK
  2. 2Division of Clinical Neurosciences, University of Edinburgh, Edinburgh, UK
  1. Correspondence to:
 Professor J Wardlaw
 Division of Clinical Neurosciences, Western General Hospital, Edinburgh EH4 2XU, UK; jwardlaw{at}


Background: The mismatch between perfusion and diffusion lesions on magnetic resonance perfusion-weighted imaging (PWI)/diffusion-weighted imaging (DWI) may help identify patients for thrombolysis. Evidence underlying this hypothesis was assessed.

Methods: All papers describing magnetic resonance PWI/DWI findings in patients with acute ischaemic stroke, and their functional and/or radiological outcome at 1 month, with or without thrombolysis were systematically reviewed.

Results: 11 papers fulfilled the inclusion criteria. Among these, there were 5 different mismatch definitions and at least 7 different PWI methods. Only 3 papers including 61 patients with and 18 without mismatch provided data on mismatch, outcome and influence of thrombolysis. Mismatch (v no mismatch) without thrombolysis was associated with a non-significant twofold increase in the odds of infarct expansion (odds ratio (OR) 2.2, 95% confidence interval (CI) 0.34 to 14.1), which did not change with thrombolysis (OR 2.0, 95% CI 0.37 to 10.9). Half of the patients without mismatch also had infarct growth (with or without thrombolysis). No data were available on functional outcome.

Conclusions: Standardised definitions of mismatch and perfusion are needed. Infarct growth may occur even in the absence of mismatch. Currently, data available on mismatch are too limited to guide thrombolysis in routine practice. More data are needed from studies including patients with and without mismatch, and randomised treatment allocation, to determine the role of mismatch.

  • DWI, diffusion-weighted imaging
  • MRI, magnetic resonance imaging
  • mRS, modified Rankin Score
  • MTT, mean transit time
  • NIHSS, National Institutes of Health Score
  • PWI, perfusion-weighted imaging
  • rt-PA, recombinant tissue-type plasminogen activator

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.


  • Published Online First 20 October 2006

  • Competing interests: None.

Linked Articles