title: Automated detection and quantification of venous beading using Fourier analysis.
abstract: Venous beading associated with diabetic retinopathy is currently assessed by means of subjective comparison to standard photographs from the modified Airlie House classification scheme. We describe a computerized grading scheme for venous beading. The algorithm, based on Fourier analysis of vessel width measurements, generates a venous beading index (VBI) for digitized colour fundus photographs. Colour photographs of local vessel segments about 1200 microns in length were evaluated by experienced graders. A comparison between the VBI and subjective grading showed good agreement. The mean VBI values across the four levels of clinical grading were significantly different (p = 0.000). Multiple comparison testing indicated that the VBI was able to significantly differentiate between all four categories except the "questionable" (grade 1) category (p < 0.05). We also found that progression of venous beading can be followed with the VBI. The results indicate that further development of automated grading of venous beading is warranted.
authors.affiliation: Department of Ophthalmology, Nova Scotia Eye Centre, Dalhousie University, Halifax.
authors.forename: V
authors.initials: V
authors.lastname: Kozousek
authors.forename: Z
authors.initials: Z
authors.lastname: Shen
authors.forename: P
authors.initials: P
authors.lastname: Gregson
authors.forename: R C
authors.initials: RC
authors.lastname: Scott
mesh_terms: D000465:Algorithms; D003930:Diabetic Retinopathy / Q000175:diagnosis*; D005451:Fluorescein Angiography; D005583:Fourier Analysis; D005654:Fundus Oculi; D006801:Humans; D007091:Image Processing, Computer-Assisted; D010781:Photography; D015203:Reproducibility of Results; D012164:Retinal Diseases / Q000175:diagnosis; D012169:Retinal Vein / Q000473:pathology*; D012680:Sensitivity and Specificity