advertisement
Abstract #46200 Published in IGR 13-2
Reliability of a computer-aided manual procedure for segmenting optical coherence tomography scans
Hood DC; Cho J; Raza AS; Dale EA; Wang MOptometry and Vision Science 2011; 88: 113-123
To assess the within- and between-operator agreement of a computer-aided manual segmentation procedure for frequency-domain optical coherence tomography scans. Four individuals (segmenters) used a computer-aided manual procedure to mark the borders defining the layers analyzed in glaucoma studies. After training, they segmented two sets of scans, an Assessment Set and a Test Set. Each set had scans from 10 patients with glaucoma and 10 healthy controls. Based on an analysis of the Assessment Set, a set of guidelines was written. The Test Set was segmented twice with a (greater-than or equal to)1 month separation. Various measures were used to compare test and retest (within-segmenter) variability and between-segmenter variability including concordance correlations between layer borders and the mean across scans (n = 20) of the mean of absolute differences between local border locations of individual scans, MEAN{mean( (Delta)LBL )}. Within-segmenter reliability was good. The mean concordance correlations values for an individual segmenter and a particular border ranged from 0.999 (plus or minus) 0.000 to 0.978 (plus or minus) 0.084. The MEAN{mean( (Delta)LBL )} values ranged from 1.6 to 4.7 (mu)m depending on border and segmenter. Similarly, between-segmenter agreement was good. The mean concordance correlations values for an individual segmenter and a particular border ranged from 0.999 (plus or minus) 0.001 to 0.992 (plus or minus) 0.023. The MEAN{mean( (Delta)LBL )} values ranged from 1.9 to 4.0 (mu)m depending on border and segmenter. The signed and unsigned average positions were considerably smaller than the MEAN{mean( (Delta)LBL )} values for both within- and between-segmenter comparisons. Measures of within-segmenter variability were only slightly larger than those of between-segmenter variability. When human segmenters are trained, the within-and between-segmenter reliability of manual border segmentation is quite good. When expressed as a percentage of retinal layer thickness, the results suggest that manual segmentation provides a reliable measure of the thickness of layers typically measured in studies of glaucoma.
D.C. Hood. Department of Psychology, Columbia University, New York, New York 10027, USA. Email: dch3@columbia.edu
Classification:
6.9.2.2 Posterior (Part of: 6 Clinical examination methods > 6.9 Computerized image analysis > 6.9.2 Optical coherence tomography)