Contrast-Free High Frame Rate Ultrasound Imaging for Assessment of Vascular Remodeling During Wound Healing

Abstract

Background

Monitoring of wound healing progression is critical due to the risk of infection, non-healing wounds, or evolution towards a chronic state. Tissue vasculature is one of the most representative features reflecting healing status. This study explores the feasibility of vascular ultrasound imaging of open wounds and the extraction of vascular-related features in a longitudinal study.

Material and methods

C57BL/6 mice received a 1 cm-diameter full-thickness wound on their dorsum and were imaged using ultrasound from the surgical day (Day 0) to 25 days post-wounding. The high frame rate, plane waves acquisitions with a 15 MHz transducer were postprocessed with Singular Value Decomposition (SVD) filtering to provide vascular information.

Results

Vascularity Index (VI) calculations showed an increased vascular signal in the wound from Day 2 post-wounding and were significantly higher from day 6 to day 10 post-wounding compared to Day 0 (p<0.05). VI values were back to the basal level after 3 weeks. In comparison, no significant difference was highlighted for the vascular signal in the peri-wound area.

Conclusions

These results show that vascular ultrasound imaging can be applied to track vascular changes of open wounds during the healing process. This approach may also be extended to other types of wounds for detecting early signs likely to cause complications.