title: Diffusion weighted MRI imaging and MES detection in the assessment of stroke origin.
abstract: OBJECTIVE
  This study compares the additional benefit of diffusion-weighted MRI (DWI) and microembolus detection by transcranial Doppler ultrasonography (TCD) in the assessment of stroke etiology.
  
  
  METHODS
  Fifty-five acute anterior circulation stroke or TIA patients were investigated by both cranial DWI and bilateral TCD of the middle cerebral arteries (1 hour).
  
  
  RESULTS
  In one of the 13 patients without acute ischemic lesions visualized on DWI, microembolic signal (MES) detection was positive. However, in 33 out of 44 patients without MES, DWI revealed at least one lesion. In two patients with unilateral territorial infarction and otherwise normal cardiovascular work-up, bilateral MES were found thus localizing the embolic source into the aortic arch or the heart. In a further patient with a dissection, the occurrence of contralateral MES raised doubts on a dissection to be the cause of the infarct.
  
  
  CONCLUSIONS
  There is a contribution of both techniques to the understanding of stroke etiology. The impact of DWI is, however, superior to that of MES detection. Longer TCD recording times may diminish this discrepancy.
authors.affiliation: Department of Neurology, University of Münster, Germany. droste2@uni-muenster.de
authors.forename: Dirk W
authors.initials: DW
authors.lastname: Droste
authors.forename: Jan
authors.initials: J
authors.lastname: Knapp
authors.forename: Michael
authors.initials: M
authors.lastname: Freund
authors.forename: Ildikó
authors.initials: I
authors.lastname: Nágy
authors.forename: Volker
authors.initials: V
authors.lastname: Schulte
authors.forename: Guido
authors.initials: G
authors.lastname: Schomacher
authors.forename: László
authors.initials: L
authors.lastname: Csiba
authors.forename: E Bernd
authors.initials: EB
authors.lastname: Ringelstein
mesh_terms: D000328:Adult; D000368:Aged; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D005583:Fourier Analysis; D006801:Humans; D008297:Male; D020768:Middle Cerebral Artery / Q000473:pathology*; D020521:Stroke / Q000175:diagnosis* / Q000209:etiology*; D017585:Ultrasonography, Doppler, Transcranial