Numerical Characterization of Quasi-Static Ultrasound Elastography for the Detection of Deep Tissue Injuries

Deep tissue injuries are subcutaneous regions of tissue breakdown associated with excessive mechanical pressure for extended period of time. These wounds are currently clinically undetectable in their early stages and result in severe burdens on not only the patients who suffer from them, but the health care system as well. The goal of this work was to numerically characterize the use of quasi-static ultrasound elastography for detecting formative and progressive deep tissue injuries. In order to numerically characterize the technique, finite-element models of sonographic B-mode imaging and tissue deformation were created. These models were fed into a local strain-estimation algorithm to determine the detection sensitivity of the technique on various parameters. Our work showed that quasi-static ultrasound elastography was able to detect and characterize deep tissue injuries over a range of lesion parameters. Simulations were validated using a physical phantom model. This work represents a step along the path to developing a clinically relevant technique for detecting and diagnosing early deep tissue injuries.