High-Resolution MR Neurography Anatomy of the Sacral Plexus

Reading magnetic resonance neurography (MRN) of the sacral plexus is challenging owing to the complicated anatomy of the pelvis and to the small caliber and complex course of many nerves in this region. Although MRN can identify the roots of the sacral plexus and its tributaries, this examination remains difficult to perform and requires competence, high-resolution sequences, and a deep knowledge of the normal imaging anatomy. The aim of this chapter is to provide a comprehensive review of the imaging anatomy of the sacral plexus to help in interpreting MRN images correctly. We will describe the anatomy on MRN of the lumbosacral trunk, first to fourth sacral nerve roots, superior and inferior gluteal nerves, sciatic nerve, lateral femoral cutaneous nerve, peroneal nerve, tibial nerve, and pudendal nerve.