First Exploration of H-scan Ultrasound Imaging in Diabetic Foot: A Feasibility Study

Diabetic foot complications are a leading cause of morbidity and lower-limb amputation worldwide, largely driven by structural and mechanical alterations of plantar soft tissues. Reverberant shear wave ultrasound elastography has shown potential in detecting increased stiffness in diabetic plantar tissue; however, stiffness alone does not fully capture microstructural remodeling at the scatterer level. H-scan ultrasound imaging is a scatterer-size-sensitive technique that encodes frequency-dependent backscatter information into color maps, providing a novel means of assessing tissue microarchitecture. In this feasibility study, we applied H-scan imaging to the plantar soft tissues of 10 diabetic patients and 3 healthy controls. Radiofrequency ultrasound data were acquired at clinically relevant sites (1st and 3rd metatarsal heads and heel), processed using a 256-filter Gaussian convolution algorithm, and analyzed with an automated region-of-interest detection method. The intensity-weighted percentage of red pixels (IWP_red), representing the prevalence of larger scatterers, was extracted as a quantitative biomarker. Results showed significantly higher IWP_red values in participants with diabetes at the 3rd metatarsal head for both feet (left: p ≤ 0.002, right: p ≤ 0.001), while no significant differences were observed at the 1st metatarsal head or heel. These findings suggest that H-scan imaging can detect microstructural alterations in diabetic plantar tissues, particularly at high-risk ulceration sites. This study provides the first evidence supporting the feasibility of H-scan ultrasound as a non-invasive, rapid, and clinically deployable tool for diabetic foot risk assessment.