title: Segmentation of progressive multifocal leukoencephalopathy lesions in fluid-attenuated inversion recovery magnetic resonance imaging.
abstract: OBJECTIVE
  The authors compared the reproducibility of a manual and a semiautomated technique for the quantitation of white-matter lesions in magnetic resonance imaging (MRI).
  
  
  METHODS
  Volumes of white-matter lesions were determined using fluid-attenuated inversion recovery MRI in 23 AIDS patients with progressive multifocal leukoencephalopathy. Manual outlining was compared to an automated method based on region growing and adaptive thresholding.
  
  
  RESULTS
  Lesion volumes from the 2 methods correlated well (61 lesions, r = 0.99, P < 10(-4)), although the volumes differed substantially (12.8% +/- 13.7%). Interscan, intrasubject reproducibility was better for the automated than the manual method (2.9% +/- 3.2% vs 12.4% +/- 16.2% volume difference, P = .02).
  
  
  CONCLUSIONS
  The automated algorithm appeared more reproducible, which renders it superior to the manual method for longitudinal studies.
authors.affiliation: Department of Computer Science, University of Southern California, Hedco Neuroscience Building, Room 30A, 3641 Watt Way, Los Angeles, CA 90089-2520, USA. itti@pollux.usc.edu
authors.forename: L
authors.initials: L
authors.lastname: Itti
authors.forename: L
authors.initials: L
authors.lastname: Chang
authors.forename: T
authors.initials: T
authors.lastname: Ernst
mesh_terms: D017088:AIDS-Related Opportunistic Infections / Q000473:pathology*; D000465:Algorithms; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D007968:Leukoencephalopathy, Progressive Multifocal / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D015203:Reproducibility of Results