Systemic Sclerosis Calcinosis Outcomes with Wearable Ultrasound Technology (SCOUT)

Abstract

Calcinosis, a debilitating complication of systemic sclerosis (SSc), affects up to 40% of patients and is typically identified only after symptom onset, when tissue damage and pain have already progressed. Current diagnostic workflows rely on reactive, high-cost imaging modalities such as MRI or CT, creating barriers to early detection and limiting routine screening in outpatient rheumatology settings. There is a critical need for an accessible, cost-effective approach that enables proactive identification of calcinosis at the point of care.

SCOUT (Systemic Sclerosis Calcinosis Outcomes with Ultrasound Technology) introduces an acoustic hydrogel-based ultrasound interface material designed to enhance the clinical utility of ultrasound for calcinosis screening. The hydrogel is engineered using tunable polyethylene glycol–polyurethane (PEG:PU) formulations to better match the acoustic impedance of soft tissue, minimize signal distortion from calcium deposits, and integrate seamlessly with existing ultrasound workflows without increasing procedural burden.

Prototype hydrogels were fabricated and evaluated using tissue-mimicking phantom models with embedded calcinosis analogs across varying sizes and depths. While imaging performance demonstrated comparable detectability to standard ultrasound gel without statistically significant improvement, the results validate the feasibility of the material as a clinically compatible interface and establish key design parameters for future optimization.

By enabling a low-cost, noninvasive screening strategy, SCOUT has the potential to shift calcinosis management from reactive to proactive care, reducing patient burden, minimizing reliance on expensive imaging, and improving accessibility to early intervention in SSc populations.

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