title: MRI-based mismatch detection in acute ischemic stroke: Optimal PWI maps and thresholds validated with PET.
abstract: Perfusion-weighted (PW) magnetic resonance imaging (MRI) is used to detect penumbral tissue in acute stroke, but the selection of optimal PW-maps and thresholds for tissue at risk detection remains a matter of debate. We validated the performance of PW-maps with 15O-water-positron emission tomography (PET) in a large comparative PET-MR cohort of acute stroke patients. In acute and subacute stroke patients with back-to-back MRI and PET imaging, PW-maps were validated with 15O-water-PET. We pooled two different cerebral blood flow (CBF) PET-maps to define the critical flow (CF) threshold, (i) quantitative (q)CBF-PET with the CF threshold <20 ml/100 g/min and (ii) normalized non-quantitative (nq)CBF-PET with a CF threshold of <70% (corresponding to <20 ml/100 g/min according to a previously published normogram). A receiver operating characteristic (ROC) curve analysis was performed to specify the accuracy and the optimal critical flow threshold of each PW-map as defined by PET. In 53 patients, (stroke to imaging: 9.8 h; PET to MRI: 52 min) PW-time-to-maximum (Tmax) with a threshold >6.1 s (AUC = 0.94) and non-deconvolved PW-time-to-peak (TTP) >4.8 s (AUC = 0.93) showed the best performance to detect the CF threshold as defined by PET. PW-Tmax with a threshold >6.1 s and TTP with a threshold >4.8 s are the most predictive in detecting the CF threshold for MR-based mismatch definition.
authors.affiliation: 1 Max-Planck-Institute for Neurological Research, Cologne, Germany.|3 Department of Neurology, Charité-Universitätsmedizin, Berlin, Germany.|4 Center for Stroke Research Berlin (CSB), Charité-Universitätsmedizin, Berlin, Germany.
authors.forename: Olivier
authors.initials: O
authors.lastname: Zaro-Weber
authors.affiliation: 2 Department of Radiology and Neuroradiology, Uniklinik Köln, Cologne, Germany.
authors.forename: Walter
authors.initials: W
authors.lastname: Moeller-Hartmann
authors.affiliation: 1 Max-Planck-Institute for Neurological Research, Cologne, Germany.
authors.forename: Dora
authors.initials: D
authors.lastname: Siegmund
authors.affiliation: 1 Max-Planck-Institute for Neurological Research, Cologne, Germany.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Kandziora
authors.affiliation: 1 Max-Planck-Institute for Neurological Research, Cologne, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Schuster
authors.affiliation: 1 Max-Planck-Institute for Neurological Research, Cologne, Germany.
authors.forename: Wolf-Dieter
authors.initials: WD
authors.lastname: Heiss
authors.affiliation: 3 Department of Neurology, Charité-Universitätsmedizin, Berlin, Germany.|4 Center for Stroke Research Berlin (CSB), Charité-Universitätsmedizin, Berlin, Germany.
authors.forename: Jan
authors.initials: J
authors.lastname: Sobesky
mesh_terms: D001931:Brain Mapping / Q000379:methods*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D015331:Cohort Studies; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D018810:Magnetic Resonance Angiography / Q000379:methods*; D010104:Oxygen Radioisotopes; D049268:Positron-Emission Tomography / Q000379:methods*; D011446:Prospective Studies; D012372:ROC Curve; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D020521:Stroke / Q000000981:diagnostic imaging* / Q000503:physiopathology
chemical_list: D010104:Oxygen Radioisotopes
keywords: Acute stroke; cerebral blood flow; cerebral ischemia; neuroimaging; penumbra; perfusion-weighted magnetic resonance imaging; positron emission tomography