The High-Frequency Ultrasound Detection of Rat Sciatic Nerve in a Crushed Injury Model.

Objective This study aimed to visualize sciatic nerve injury in rats using ultrasound imaging in a crushed injury model. Methods Adult male Sprague-Dawley rats were subjected to a left sciatic nerve crush operation. Then, high-frequency ultrasound was used to image both sciatic nerves at 2 days and at 1, 2, 3, 4, and 6 weeks after surgery. Results Normal uninjured nerves have uniform thickness, display a smooth epineurium and inner adventitia, and are oblong in transverse sections. After the crush operation, nerve thickness increased, the inner echo signal decreased, the image of the epineurium became obscured and coarse before becoming smooth again, and transverse sections of the nerve fibers changed from being semicircular to oval in shape before becoming elliptical again. These observations were consistent with pathological changes associated with nerve injury. Conclusions High-frequency ultrasound is capable of capturing dynamic changes in rat sciatic nerves in a crushed injury model. This can be used as an auxiliary method of evaluation in traditional peripheral nerve injury experiments.