title: Computed tomography-based quantification of lesion water uptake identifies patients within 4.5 hours of stroke onset: A multicenter observational study.
abstract: Many patients with stroke cannot receive intravenous thrombolysis because the time of symptom onset is unknown. We tested whether computed tomography (CT)-based quantification of water uptake in the ischemic tissue can identify patients with stroke onset within 4.5 hours, the time window of thrombolysis.
  
  
  
  Perfusion CT was used to identify ischemic brain tissue, and its density was measured in native CT and related to the density of the corresponding area of the contralateral hemisphere to quantify lesion water uptake. The optimal cutoff value of water uptake distinguishing stroke onset within and beyond 4.5 hours was calculated in patients with proximal middle cerebral artery occlusion (derivation cohort) with known time of symptom onset. The so-derived cutoff value was validated in a prospective cohort from other stroke centers.
  
  
  
  Of 178 patients of the derivation cohort, 147 (82.6%) had CT within 4.5 hours. Percentage water uptake was significantly lower in patients with stroke onset within compared to beyond 4.5 hours. The area under the receiver operating characteristic curve for distinguishing these patient groups according to percentage water uptake was 0.999 (95% confidence interval = 0.996-1.000, p < 0.001) with an optimal cutoff value of 11.5%. Applying this cutoff to the validation cohort of 240 patients, sensitivity was 98.6%, specificity 90.5%, positive predictive value 99.1%, and negative predictive value 86.4%.
  
  
  
  Quantification of brain water uptake identifies stroke patients with symptom onset within 4.5 hours with high accuracy and may guide the decision to use thrombolysis in patients with unknown time of stroke onset. Ann Neurol 2016;80:924-934.
authors.affiliation: Department of Neurology, University of Münster, Münster.
authors.forename: Jens
authors.initials: J
authors.lastname: Minnerup
authors.affiliation: Department of Diagnostic and Interventional Neuroradiology, University Medical Center Hamburg-Eppendorf, Hamburg.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Broocks
authors.affiliation: Department of Neurology, University of Münster, Münster.
authors.forename: Judith
authors.initials: J
authors.lastname: Kalkoffen
authors.affiliation: Institute of Diagnostic Radiology and Neuroradiology, University of Medicine Greifswald, Greifswald.
authors.forename: Soenke
authors.initials: S
authors.lastname: Langner
authors.affiliation: Institute for Diagnostic and Interventional Neuroradiology, University Medicine Göttingen, Göttingen.
authors.forename: Michael
authors.initials: M
authors.lastname: Knauth
authors.affiliation: Institute for Diagnostic and Interventional Neuroradiology, University Medicine Göttingen, Göttingen.
authors.forename: Marios Nikos
authors.initials: MN
authors.lastname: Psychogios
authors.affiliation: Institute of Epidemiology and Social Medicine, University of Münster, Münster.
authors.forename: Heike
authors.initials: H
authors.lastname: Wersching
authors.affiliation: Institute of Epidemiology and Social Medicine, University of Münster, Münster.
authors.forename: Anja
authors.initials: A
authors.lastname: Teuber
authors.affiliation: Department of Clinical Radiology, University of Münster, Münster.
authors.forename: Walter
authors.initials: W
authors.lastname: Heindel
authors.affiliation: Department of Neuroradiology, Asklepios Hospital Altona, Hamburg.
authors.forename: Bernd
authors.initials: B
authors.lastname: Eckert
authors.affiliation: Department of Neurology, University of Münster, Münster.
authors.forename: Heinz
authors.initials: H
authors.lastname: Wiendl
authors.affiliation: Institute of Neuroradiology, University Medical Center Schleswig-Holstein, Lübeck, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Schramm
authors.affiliation: Department of Diagnostic and Interventional Neuroradiology, University Medical Center Hamburg-Eppendorf, Hamburg.
authors.forename: Jens
authors.initials: J
authors.lastname: Fiehler
authors.affiliation: Department of Diagnostic and Interventional Neuroradiology, University Medical Center Hamburg-Eppendorf, Hamburg.|Department of Clinical Radiology, University of Münster, Münster.|Institute of Neuroradiology, University Medical Center Schleswig-Holstein, Lübeck, Germany.
authors.forename: André
authors.initials: A
authors.lastname: Kemmling
mesh_terms: D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging / Q000378:metabolism; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D008297:Male; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D020521:Stroke / Q000000981:diagnostic imaging* / Q000378:metabolism; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D014867:Water / Q000378:metabolism*
chemical_list: D014867:Water