Entrapment Neuropathies in the Upper and Lower Limbs: Anatomy and MRI Features
Extensive tear of the left hamstring muscle origin with sciatic nerve scarring in a 54-year-old patient after a water skiing injury. Axial T1-weighted images (a) and (b) identify a tear of left hamstring at the level of origin (black arrow in (a)). There is thickening and abnormal signal of the adjacent sciatic nerve (white arrowheads) extending distally (b), consistent with secondary entrapment from scarring. This finding is also demonstrated on a sagittal fat-saturated T2-weighted image (c). On the right side, the right sciatic nerve (black arrowheads) has normal caliber and signal intensity, and an intact hamstring muscle origin is present (star).