title: Sensitivity of Diffusion-Weighted STEAM MRI and EPI-DWI to Infratentorial Ischemic Stroke.
abstract: OBJECTIVE
  To assess the sensitivity of stimulated echo acquisition mode diffusion weighted imaging (STEAM-DWI) to ischemic stroke in comparison to echo-planar imaging diffusion weighted imaging (EPI-DWI) in the infratentorial compartment.
  
  
  METHODS
  Fifty-seven patients presenting with clinical features of infratentorial stroke underwent STEAM-DWI, high-resolution EPI-DWI (HR-DWI, 2.5 mm slice thickness) and low-resolution EPI-DWI (LR-DWI, 5 mm slice thickness). Four readers assessed the presence of ischemic lesions and artifacts. Agreement between sequences and interobserver agreement on the presence of ischemia were calculated. The sensitivities of the DWI sequences were calculated in 45 patients with a confirmed diagnosis of infratentorial stroke.
  
  
  RESULTS
  Median time from symptom onset to imaging was 24 hours. STEAM-DWI agreed with LR-DWI in 89.5% of cases (kappa = 0.72, p<0.0001) and with HR-DWI in 89.5% of cases (kappa = 0.68, p<0.0001). STEAM-DWI showed fewer intraparenchymal artifacts (1/57) than HR-DWI (44/57) and LR-DWI (41/57). Ischemia was visible in 87% of cases for LR-DWI, 93% of cases for HR-DWI, and 89% of cases for STEAM-DWI. Interobserver agreement was good for STEAM-DWI (kappa = 0.62, p<0.0001).
  
  
  CONCLUSIONS
  Compared to the best currently available MR sequence for detecting ischemia (HR-DWI), STEAM-DWI shows fewer artifacts and a similar sensitivity to infratentorial stroke.
authors.affiliation: Center for Stroke Research Berlin, Charité - Universitätsmedizin Berlin, Berlin, Germany.|NeuroCure Cluster of Excellence, Charité - Universitätsmedizin Berlin, Berlin, Germany.|International Graduate Program Medical Neurosciences, Charité - Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Ahmed A
authors.identifier: http://orcid.org/0000-0003-1752-4305
authors.initials: AA
authors.lastname: Khalil
authors.affiliation: Klinik für Neurochirurgie, Universitätsklinikum Freiburg, Freiburg im Breisgau, Germany.
authors.forename: Marc
authors.initials: M
authors.lastname: Hohenhaus
authors.affiliation: Center for Stroke Research Berlin, Charité - Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Claudia
authors.initials: C
authors.lastname: Kunze
authors.affiliation: Center for Stroke Research Berlin, Charité - Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Wolf
authors.initials: W
authors.lastname: Schmidt
authors.affiliation: Center for Stroke Research Berlin, Charité - Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Brunecker
authors.affiliation: Center for Stroke Research Berlin, Charité - Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Kersten
authors.initials: K
authors.lastname: Villringer
authors.affiliation: Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany.
authors.forename: Klaus-Dietmar
authors.initials: KD
authors.lastname: Merboldt
authors.affiliation: Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany.
authors.forename: Jens
authors.initials: J
authors.lastname: Frahm
authors.affiliation: Center for Stroke Research Berlin, Charité - Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Jochen B
authors.initials: JB
authors.lastname: Fiebach
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016477:Artifacts; D038524:Diffusion Magnetic Resonance Imaging; D017352:Echo-Planar Imaging; D005260:Female; D006801:Humans; D007511:Ischemia / Q000150:complications*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D059629:Signal-To-Noise Ratio; D020521:Stroke / Q000150:complications* / Q000000981:diagnostic imaging*