title: Automated diagnosis of retinopathy by content-based image retrieval.
abstract: OBJECTIVE
  To describe a novel computer-based image analysis method that is being developed to assist and automate the diagnosis of retinal disease.
  
  
  METHODS
  Content-based image retrieval is the process of retrieving related images from large database collections using their pictorial content. The content feature list becomes the index for storage, search, and retrieval of related images from a library based upon specific visual characteristics. Low-level analyses use feature description models and higher-level analyses use perceptual organization and spatial relationships, including clinical metadata, to extract semantic information.
  
  
  RESULTS
  We defined, extracted, and tested a large number of region- and lesion-based features from a dataset of 395 retinal images. Using a statistical hold-one-out method, independent queries for each image were submitted to the system and a diagnostic prediction was formulated. The diagnostic sensitivity for all stratified levels of age-related macular degeneration ranged from 75% to 100%. Similarly, the sensitivity of detection and accuracy for proliferative diabetic retinopathy ranged from 75% to 91.7% and for nonproliferative diabetic retinopathy, ranged from 75% to 94.7%. The overall purity of the diagnosis (specificity) for all disease states in the dataset was 91.3%.
  
  
  CONCLUSIONS
  The probabilistic nature of content-based image retrieval permits us to make statistically relevant predictions regarding the presence, severity, and manifestations of common retinal diseases from digital images in an automated and deterministic manner.
authors.affiliation: Department of Ophthalmology, University of Tennessee Health Science Center, Memphis, Tennessee, USA. echaum@utmem.edu
authors.forename: Edward
authors.initials: E
authors.lastname: Chaum
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Karnowski
authors.forename: V Priya
authors.initials: VP
authors.lastname: Govindasamy
authors.forename: Mohamed
authors.initials: M
authors.lastname: Abdelrahman
authors.forename: Kenneth W
authors.initials: KW
authors.lastname: Tobin
mesh_terms: D001185:Artificial Intelligence; D019295:Computational Biology; D003930:Diabetic Retinopathy / Q000175:diagnosis*; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D016247:Information Storage and Retrieval; D008268:Macular Degeneration / Q000175:diagnosis*; D010781:Photography; D012171:Retinal Vessels / Q000473:pathology*; D012680:Sensitivity and Specificity