An Elastography Framework for Use in Dermoscopy

Multiple skin conditions exist which involve clinically significant changes in elastic properties. Early detection of such changes may prove critical in formulating a proper treatment plan. However, most diagnoses still rely primarily on visual inspection followed by biopsy for histological analysis. As a result, there would be considerable clinical benefit if a noninvasive technology to study the skin were available. The primary hypothesis of this work is that skin elasticity may serve as an important method for assisting diagnosis and treatment. Perhaps the most apparent application would be for the differentiation of skin cancers, which are a growing health concern in the United States as total annual cases are now being reported in the millions by the American Cancer Society. In this paper, we use our novel modality independent elastography (MIE) method to perform dermoscopic skin elasticity evaluation. The framework involves applying a lateral stretching to the skin in which dermoscopic images are acquired before and after mechanical excitation. Once collected, an iterative elastographic reconstruction method is used to generate images of tissue elastic properties and is based on a twodimensional (2-D) membrane model framework. Simulation studies are performed that show the effects of three-dimensional data, varying subdermal tissue thickness, and nonlinear large deformations on the framework. In addition, a preliminary in vivo reconstruction is demonstrated. The results are encouraging and indicate good localization with satisfactory degrees of elastic contrast resolution.