Sciatic nerve and surrounding structures

(A) This image shows the polyfascicular echotexture of the sciatic nerve (arrow) in the proximal thigh after LA injection for regional block. LA can be seen surrounding the sciatic nerve in this short-axis view. The conjoint tendon of the biceps femoris and semitendinosus (arrowhead) points to the medial aspect of the sciatic nerve. The echogenic tendon of the semimembranosus is seen medial to the sciatic nerve (dashed arrow).
(B) LA appears dark (ie, hypoechoic), and tracks along both the superficial and deep surfaces of the nerve in long-axis view (arrows).