Novel Imaging Method Shows Promise for Assessing Scleroderma Skin Changes

An emerging noninvasive imaging technique known as spatial frequency domain imaging, or SFDI, has shown potential for evaluating skin fibrosis in patients with systemic sclerosis, commonly called scleroderma. Researchers found that the optical technology correlated with standard clinical scoring methods and histology, suggesting it could eventually support disease monitoring.

Published in Lancet Rheumatology, the study led by Andreea M. Bujor, MD, PhD, of Boston University, and colleagues examined whether light-based imaging could overcome limitations associated with traditional evaluation methods. The modified Rodnan Skin Score, which relies on a clinician physically pinching the skin, is subject to variable accuracy based on examiner skill. Meanwhile, definitive assessments through microscopic inspection of biopsies can only be performed infrequently, potentially missing subtle disease progression.

The clinical study involved 49 patients with systemic sclerosis and 25 healthy controls who completed evaluations at a clinic. Participants underwent assessments using ultrasound, durometry, and SFDI scans. A subset of patients participated in a longitudinal phase, attending visits every three months for the first year and every six months for the following three years. The research team tracked two specific SFDI parameters: diffuse reflectance and the reduced scattering coefficient.

Results indicated that values for both optical parameters were significantly lower in patients compared with healthy controls, regardless of their Rodnan scores. Furthermore, changes in SFDI parameters over time correlated with changes in the modified Rodnan Skin Score and matched findings from histological biopsy analyses of fibrosis. The researchers noted that because SFDI uses ordinary visible light and requires no radiation or tissue removal, it allowed for frequent serial testing over a four-year period.

Despite the encouraging correlations, the study authors emphasized important limitations. The investigation involved a modest patient sample that may not fully represent the broader systemic sclerosis population. Additionally, the analysis did not account for potential confounders such as patient medications, smoking status, or sun exposure. Because longitudinal sample sizes were small and change-score analyses can be influenced by regression to the mean, the authors stressed that findings must be interpreted cautiously.

Future Steps and Clinical Outlook

• Researchers emphasize that SFDI is not currently ready for widespread clinical use.
• Future priorities include optimizing handheld device designs and validating the technology in larger, more diverse prospective cohorts.
• Investigators aim to establish clear thresholds for meaningful change and integrate patient-reported outcomes to connect optical measurements directly with patient-perceived improvement.