title: Computer-Based Image Analysis for Plus Disease Diagnosis in Retinopathy of Prematurity: Performance of the "i-ROP" System and Image Features Associated With Expert Diagnosis.
abstract: OBJECTIVE
  We developed and evaluated the performance of a novel computer-based image analysis system for grading plus disease in retinopathy of prematurity (ROP), and identified the image features, shapes, and sizes that best correlate with expert diagnosis.
  
  
  METHODS
  A dataset of 77 wide-angle retinal images from infants screened for ROP was collected. A reference standard diagnosis was determined for each image by combining image grading from 3 experts with the clinical diagnosis from ophthalmoscopic examination. Manually segmented images were cropped into a range of shapes and sizes, and a computer algorithm was developed to extract tortuosity and dilation features from arteries and veins. Each feature was fed into our system to identify the set of characteristics that yielded the highest-performing system compared to the reference standard, which we refer to as the "i-ROP" system.
  
  
  RESULTS
  Among the tested crop shapes, sizes, and measured features, point-based measurements of arterial and venous tortuosity (combined), and a large circular cropped image (with radius 6 times the disc diameter), provided the highest diagnostic accuracy. The i-ROP system achieved 95% accuracy for classifying preplus and plus disease compared to the reference standard. This was comparable to the performance of the 3 individual experts (96%, 94%, 92%), and significantly higher than the mean performance of 31 nonexperts (81%).
  
  
  CONCLUSIONS
  This comprehensive analysis of computer-based plus disease suggests that it may be feasible to develop a fully-automated system based on wide-angle retinal images that performs comparably to expert graders at three-level plus disease discrimination.
  
  
  CONCLUSIONS
  Computer-based image analysis, using objective and quantitative retinal vascular features, has potential to complement clinical ROP diagnosis by ophthalmologists.
authors.affiliation: Cognitive Systems Laboratory, Northeastern University, Boston, MA, USA.
authors.forename: Esra
authors.initials: E
authors.lastname: Ataer-Cansizoglu
authors.affiliation: Department of Computer Science, Universidade da Coruña, A Coruña, Spain.
authors.forename: Veronica
authors.initials: V
authors.lastname: Bolon-Canedo
authors.affiliation: Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, OR, USA.
authors.forename: J Peter
authors.initials: JP
authors.lastname: Campbell
authors.affiliation: Cognitive Systems Laboratory, Northeastern University, Boston, MA, USA.
authors.forename: Alican
authors.initials: A
authors.lastname: Bozkurt
authors.affiliation: Cognitive Systems Laboratory, Northeastern University, Boston, MA, USA.
authors.forename: Deniz
authors.initials: D
authors.lastname: Erdogmus
authors.affiliation: Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, USA.
authors.forename: Jayashree
authors.initials: J
authors.lastname: Kalpathy-Cramer
authors.affiliation: Department of Ophthalmology, Weill Cornell Medical College, New York, NY, USA.
authors.forename: Samir
authors.initials: S
authors.lastname: Patel
authors.affiliation: Department of Ophthalmology, Weill Cornell Medical College, New York, NY, USA.
authors.forename: Karyn
authors.initials: K
authors.lastname: Jonas
authors.affiliation: Department of Ophthalmology, Weill Cornell Medical College, New York, NY, USA.
authors.forename: R V Paul
authors.initials: RV
authors.lastname: Chan
authors.affiliation: Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, OR, USA.
authors.forename: Susan
authors.initials: S
authors.lastname: Ostmo
authors.affiliation: Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, OR, USA ; Departments of Medical Informatics and Clinical Epidemiology, Oregon Health & Science University, Portland, OR, USA.
authors.forename: Michael F
authors.initials: MF
authors.lastname: Chiang
keywords: computer-based image analysis; machine learning; retinopathy of prematurity