Tissue displacements during acupuncture using ultrasound elastography techniques.

Acupuncture needle manipulation has been previously shown to result in measurable changes in connective tissue architecture in animal experiments. In this study, we used a novel in vivo ultrasound (US)-based technique to quantify tissue displacement during acupuncture manipulation in humans. B-scan ultrasonic imaging was performed on the thighs of 12 human subjects at different stages of needle motion, including varying amounts of rotation, downward and upward movement performed with a computer-controlled acupuncture needling instrument. Tissue displacements, estimated using cross-correlation techniques, provided successful mapping and quantitative analysis of spatial and temporal tissue behavior during acupuncture needle manipulation. Increasing amounts of rotation had a significant linear effect on tissue displacement during downward and upward needle motion, as well as on rebound tissue displacement after downward needle movement. In addition to being a valuable tool for studies of acupuncture's mechanism of action, this technique may have applications to other types of needling including biopsies.