Ultrasound Surface Wave Elastography for Assessing Scleroderma

Scleroderma, or systemic sclerosis (SSc), is a multi-organ connective tissue disease characterized by immune dysregulation and tissue fibrosis. Skin disease is both a disabling feature of SSc and a predictor of visceral involvement and increased mortality. The Modified Rodnan Skin Score (MRSS) is currently the most common clinical method for assessing skin. We developed ultrasound surface wave elastography (USWE) techniques to measure skin surface wave speeds and analyze skin viscoelasticity. The objective of this research was to determine the correlations of skin surface wave speed and skin viscoelasticity with MRSS. Twenty-six SSc patients were studied using USWE and the MRSS. The subject was tested in a sitting position while his or her left or right forearm and upper arm were placed horizontally on a pillow in a relaxed state. The skin of both left and right forearms and upper arms of patients was tested using USWE. Surface wave speeds are positively correlated with the MRSS. Skin elasticity is also positively correlated with the MRSS. However, there was no correlation between skin viscosity and the MRSS for these SSc patients. We will further study if skin viscosity is sensitive enough to detect early edema from inflammation changes of SSc.