EVALUATION OF MANUAL VS SEMIAUTOMATED DELINEATION OF LIVER-LESIONS ONCT IMAGES

In this paper we compare a semi-automated delineation method with tota lly manual delineation for area quantification, with respect to effici ency, quality, and intra- and interobserver variability. Liver lesions on 28 CT images were delineated by three observers, twice using compl etely manual delineation and twice using a semi-automated method. Quan titative comparisons were performed with respect to delineated area an d time required for the delineation tasks. Subjective comparisons were performed with respect to efficiency and perceived quality of the sem i-automated method. The areas obtained using semi-automated delineatio n were significantly smaller (11%) than those obtained using totally m anual delineation. Intraobserver and interobserver variability with th e semi-automated method were approximately three times lower than with manual delineation. Efficiency of the semi-automated method was subje ctively rated favorable, although further improvements are possible. W ith respect to quality, the semi-automated method was ranked better th an the manual method in 73% of cases.