title: Quantitative T2'-mapping in acute ischemic stroke.
abstract: OBJECTIVE
  Quantitative T2'-mapping detects regional changes in the relation of oxygenated and deoxygenated haemoglobine and might reflect areas with increased oxygen extraction. T2'-mapping in conjunction with an elaborate algorithm for motion correction was performed in patients with acute large-vessel stroke, and quantitative T2'-values were determined within the diffusion-weighted imaging lesion and perfusion-restricted tissue.
  
  
  METHODS
  Eleven patients (median age, 71 years) with acute middle cerebral or internal carotid artery occlusion underwent MRI before scheduled endovascular treatment. MR-examination included diffusion- and perfusion-weighted imaging and quantitative, motion-corrected mapping of T2'. Time-to-peak maps were thresholded for different degrees of perfusion delays (eg, ≥0 s, ≥ 2s) when compared with a reference time-to-peak value from healthy contralateral tissue. Mean T2'-values in areas with reduced apparent diffusion coefficient and in areas with impaired perfusion were compared with T2'-values in corresponding contralateral areas.
  
  
  RESULTS
  Median time between symptom onset and MRI was 238 minutes. T2'-values were significantly reduced within the apparent diffusion coefficient -lesion when compared with contralateral healthy tissue (83 ms [67, 97] versus 97 ms [91, 111]; P<0.003). In perfusion-restricted tissue, T2'-values were also significantly lower when compared with contralateral healthy tissue (ie, for time to peak, ≥0 s 93 ms [86, 102] versus 104 [90, 110]; P=0.008) but were significantly higher than within the apparent diffusion coefficient lesion. The severity of the perfusion impairment had no influence on median T2'-values.
  
  
  CONCLUSIONS
  Motion-corrected T2'-mapping reveals significant and gradually declining values from healthy to perfusion-disturbed to apparent diffusion coefficient-restricted tissue. Current T2'-mapping can differentiate between the ischemic core and the perfusion-impaired areas but not on its own between penumbral and oligemic tissue.
authors.affiliation: From the Department of Neurology (S.B., A.S., O.C.S.), Institute for Neuroradiology (M.W., E.H.); and Brain Imaging Center (R.D., U.N.), University Hospital Frankfurt, Goethe University, Frankfurt, Germany.
authors.forename: Sonja
authors.initials: S
authors.lastname: Bauer
authors.affiliation: From the Department of Neurology (S.B., A.S., O.C.S.), Institute for Neuroradiology (M.W., E.H.); and Brain Imaging Center (R.D., U.N.), University Hospital Frankfurt, Goethe University, Frankfurt, Germany.
authors.forename: Marlies
authors.initials: M
authors.lastname: Wagner
authors.affiliation: From the Department of Neurology (S.B., A.S., O.C.S.), Institute for Neuroradiology (M.W., E.H.); and Brain Imaging Center (R.D., U.N.), University Hospital Frankfurt, Goethe University, Frankfurt, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Seiler
authors.affiliation: From the Department of Neurology (S.B., A.S., O.C.S.), Institute for Neuroradiology (M.W., E.H.); and Brain Imaging Center (R.D., U.N.), University Hospital Frankfurt, Goethe University, Frankfurt, Germany.
authors.forename: Elke
authors.initials: E
authors.lastname: Hattingen
authors.affiliation: From the Department of Neurology (S.B., A.S., O.C.S.), Institute for Neuroradiology (M.W., E.H.); and Brain Imaging Center (R.D., U.N.), University Hospital Frankfurt, Goethe University, Frankfurt, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Deichmann
authors.affiliation: From the Department of Neurology (S.B., A.S., O.C.S.), Institute for Neuroradiology (M.W., E.H.); and Brain Imaging Center (R.D., U.N.), University Hospital Frankfurt, Goethe University, Frankfurt, Germany.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Nöth
authors.affiliation: From the Department of Neurology (S.B., A.S., O.C.S.), Institute for Neuroradiology (M.W., E.H.); and Brain Imaging Center (R.D., U.N.), University Hospital Frankfurt, Goethe University, Frankfurt, Germany. o.singer@em.uni-frankfurt.de.
authors.forename: Oliver C
authors.initials: OC
authors.lastname: Singer
mesh_terms: D000368:Aged; D002545:Brain Ischemia / Q000175:diagnosis* / Q000378:metabolism; D001931:Brain Mapping / Q000379:methods / Q000592:standards*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods / Q000592:standards*; D017352:Echo-Planar Imaging / Q000379:methods / Q000592:standards*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D020521:Stroke / Q000175:diagnosis* / Q000378:metabolism
keywords: magnetic; positron-emission tomography; resonance imaging; stroke