title: [Development of an algorithm for the detection of early signs of cerebral ischemia on CT images].
abstract: This paper describes an approach to automatically detect the parenchymal hypoattenuation of hyperacute stroke in nonenhanced computed tomography (CT) images. This technique is based on a comparison between the CT values histograms of right and left brains. A subtraction curve that was regarded as an output value was calculated by subtracting the right-hemispherical histogram from the left-hemispherical histogram obtained from one of the region-of-interest (ROI) sets on an image. The output value was used to assess whether hypoattenuation exists on CT images with a threshold value. If judged abnormal, a rectangular region including a whole or partial hypoattenuation area was detected from the ROI. Twenty-six cases with hypoattenuation and 30 cases without hypoattenuation were included in this study. As a result of our experiments, the sensitivity of this method in detecting hypoattenuation was found to be 92%, with approximately 0.16 false-positive per image. Our preliminary experimental results indicated that the proposed technique can be used for the automated detection of parenchymal hypoattenuation of hyperacute stroke on nonenhanced CT images.
authors.affiliation: Department of Radiology, Sendai City Hospital.
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Takahashi
authors.forename: Yongbum
authors.initials: Y
authors.lastname: Lee
authors.forename: Du-Yih
authors.initials: DY
authors.lastname: Tsai
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Ishii
mesh_terms: D000368:Aged; D000465:Algorithms; D002545:Brain Ischemia / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D012680:Sensitivity and Specificity; D013382:Subtraction Technique; D014057:Tomography, X-Ray Computed