Sonographic Tracking of the Lower Limb Peripheral Nerves: A Pictorial Essay and Video Demonstration.

Compared with the upper limbs, sonographic tracking of peripheral nerves in the lower limbs is more challenging. The overlying muscles are larger, hindering visualization of the deeply embedded nerves by using a linear transducer. The use of a curvilinear transducer-providing an extended view with better penetration for the field of interest-may be useful for scanning the nerves in the hip and thigh. Application of the Doppler mode helps localization of the target nerve by identifying the accompanying vessels. Aiming to demonstrate the relevant tracking techniques, the present article comprises a series of ultrasound images and videos showing how to scan the nerves in the lower limb, that is, femoral, obturator, pudendal, lateral femoral cutaneous, sciatic, saphenous, sural, tibial, and peroneal nerves.