Using multispectral photoacoustic tomography for imaging scleroderma in the hand

Scleroderma (SD) is a rare autoimmune disease, which is divided into two categories: the localized SD and systemic SD. The localized SD mainly causes skin thickening of the fingers, whereas the systemic SD can further affect the blood vessels and internal organs. In this pilot study, the multispectral photoacoustic elastic tomography (PAET) imaging technique was used to recover quantitative physiological and elastic parameters of biological tissues for the diagnosis of SD. Three healthy subjects and three scleroderma patients were recruited and clinically examined by a rheumatologist, and then their hand /fingers were scanned by the both the commercial MRI and our home-made photoacoustic imaging system. Physiological parameters including oxygen saturation (STO2), deoxy-hemoglobin (Hb) and oxy-hemoglobin (HbO(2)) concentrations and mechanical properties such as bulk modulus images were reconstructed by using the developed PAET reconstruction method. Our imaging results demonstrated that the physiological and elastic parameters exhibit striking differences between the SD and healthy fingers, indicating that these indicators can serve as molecular signatures for the early detection of SD. These quantitative physiological properties and bulk modulus may also pave a new path for improved understanding the pathological mechanism of SD.