title: Sensitivity of visual and quantitative detection of middle cerebral artery occlusion on non-contrast-enhanced computed tomography.
abstract: BACKGROUND
  This study aims to investigate diagnostic sensitivity and reliability for the detection of middle cerebral artery occlusion (MCAO) on non-contrast-enhanced computed tomography (NECT) by visual assessment (VA), Hounsfield unit (HU) measurement, calculation of the Hounsfield unit/hematocrit (HU/Hct) ratio, and combination of visual assessment and attenuation measurement (VA + HU).
  
  
  METHODS
  NECT of 18 patients with angiographically proven MCAO and 18 patients without MCAO were reviewed by two blinded observers. Visual assessment of presence or absence of a hyperdense sign was followed by HU measurement of both middle cerebral arteries (MCA). Sensitivity, specificity, positive predictive value, and negative predictive value were calculated for VA, HU measurement, HU/Hct ratio, and VA + HU measurement. Receiver operating characteristic curve analysis (ROC) was performed to determine the optimal cut-off values for MCAO using attenuation measurements or HU/Hct ratio.
  
  
  RESULTS
  Diagnostic sensitivity/specificity was 63%/91% for VA, 56%/88% for attenuation measurement, 68 %/81 % for HU/Hct ratio, and 75%/78% for VA + HU. ROC curve analysis revealed cut-off values of >42.5 HU for attenuation measurements and >1.12 HU/Hct for HU/Hct ratio.
  
  
  CONCLUSIONS
  Combination of visual assessment with additional attenuation measurement with a cut-off value of 42.5 HU is recommended for most sensitive and reliable detection of MCAO on NECT.
authors.affiliation: Center for Radiology and Endoscopy Department of Diagnostic and Interventional Neuroradiology, University Medical Center Hamburg-Eppendorf, Haus Ost 22 (O 22) Martinistr 52, 20246, Hamburg, Germany, m.ernst@uke.de.
authors.forename: M
authors.initials: M
authors.lastname: Ernst
authors.forename: J M
authors.initials: JM
authors.lastname: Romero
authors.forename: J H
authors.initials: JH
authors.lastname: Buhk
authors.forename: A
authors.initials: A
authors.lastname: Kemmling
authors.forename: J
authors.initials: J
authors.lastname: Fiehler
authors.forename: M
authors.initials: M
authors.lastname: Groth
mesh_terms: D000368:Aged; D003287:Contrast Media; D005260:Female; D006801:Humans; D020244:Infarction, Middle Cerebral Artery / Q000000981:diagnostic imaging*; D008297:Male; D015588:Observer Variation; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods / Q000706:statistics & numerical data
chemical_list: D003287:Contrast Media