Validation of segmentation techniques for digital dermoscopy.

Skin research and technology : official journal of International Society for Bioengineering and the Skin (ISBS) [and] International Society for Digital Imaging of Skin (ISDIS) [and] International Society for Skin Imaging (ISSI)

PubMedID: 12423543

Joel G, Schmid-Saugeon P, Guggisberg D, Cerottini JP, Braun R, Krischer J, Saurat JH, Murat K. Validation of segmentation techniques for digital dermoscopy. Skin Res Technol. 2002;8(4):240-9.
PURPOSE
This study aims at evaluating two automatic contour detection techniques especially developed for dermoscopic images.

METHODS
Twenty-five images of lesions with a fuzzy boundary have been randomly selected. Five dermatologists experienced in dermoscopy have manually drawn the border of all the lesions and repeated the procedure after two and four weeks. The ability of a dermatologist to reproduce its own results was evaluated by measuring the non-overlapping area enclosed by its three successive contours. The interobserver variability evaluated the contour accuracy when using automatic or manual drawings. The mean probability that a pixel has been misclassified was computed for every observer and automatic technique.

RESULTS
Experts in dermoscopy are not able to reproduce measurements precisely and the two automatic techniques had a lower misclassification probability than those obtained by each dermatologist.

CONCLUSION
This study demonstrates that a single dermatologist should not be used as a reference, and subjective validation of lesion contour is inaccurate outside an experts's group. It is argued that image processing techniques for computer-aided diagnosis must show the best compromise within such a group.