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lüll Reliability of a computer-aided manual procedure for segmenting optical coherence tomography scans Hood DC; Cho J; Raza AS; Dale EA; Wang MOptom Vis Sci 2011[Jan]; 88 (1): 113-23PURPOSE: To assess the within- and between-operator agreement of a computer-aided manual segmentation procedure for frequency-domain optical coherence tomography scans. METHODS: 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 >/=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, MEANmean( DeltaLBL ). RESULTS: Within-segmenter reliability was good. The mean concordance correlations values for an individual segmenter and a particular border ranged from 0.999 +/- 0.000 to 0.978 +/- 0.084. The MEANmean( DeltaLBL ) values ranged from 1.6 to 4.7 mum 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 +/- 0.001 to 0.992 +/- 0.023. The MEANmean( DeltaLBL ) values ranged from 1.9 to 4.0 mum depending on border and segmenter. The signed and unsigned average positions were considerably smaller than the MEANmean( DeltaLBL ) values for both within- and between-segmenter comparisons. Measures of within-segmenter variability were only slightly larger than those of between-segmenter variability. CONCLUSIONS: 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.|Artifacts[MESH]|Diagnosis, Computer-Assisted/*standards[MESH]|Glaucoma/*diagnosis[MESH]|Humans[MESH]|Observer Variation[MESH]|Reproducibility of Results[MESH]|Retina/*pathology[MESH]|Tomography, Optical Coherence/*methods/*standards[MESH] |