Role of magnetic resonance imaging in entrapment and compressive neuropathy - what, where, and how to see the peripheral nerves on the musculoskeletal magnetic resonance image: part 1. Overview and lower extremity.
The diagnosis of nerve entrapment and compressive neuropathy has been traditionally based on the clinical and electrodiagnostic examinations. As a result of improvements in the magnetic resonance (MR) imaging modality, it plays not only a fundamental role in the detection of space-occupying lesions but also a compensatory role in clinically and electrodiagnostically inconclusive cases. Although ultrasound has undergone further development in the past decades and shows high resolution capabilities, it has inherent limitations due to its operator dependency. We review the general concepts that should be known to evaluate the entrapment and compressive neuropathy in MR imaging. We also review the course of normal peripheral nerves, as well as various clinical demonstrations and pathological features of compressed and entrapped nerves in the lower extremities on MR imaging, according to the nerves involved. The common sites of nerve entrapment of the lower extremity are as follows: sciatic nerve around the piriformis muscle; tibial nerve at the popliteal fossa and tarsal tunnel, common peroneal nerve around the fibular neck, and digital nerve near the metatarsal head. Although MR imaging can depict the peripheral nerves in the extremities effectively, radiologists should be familiar with nerve pathways, common sites of nerve compression, and common space-occupying lesions resulting in nerve compression in MR imaging.
Kim
Sungjun
S
Department of Diagnostic Radiology, College of Medicine, Yonsei University, 134, Shinchondong, Seodaemun-ku, 120-752 Seoul, South Korea.
Choi
Jin-Young
JY
Huh
Yong-Min
YM
Song
Ho-Taek
HT
Lee
Sung-Ah
SA
Kim
Seung Min
SM
Suh
Jin-Suck
JS
D006801:Humans; D007866:Leg / Q000294:innervation*; D008279:Magnetic Resonance Imaging; D009408:Nerve Compression Syndromes / Q000175:diagnosis*; D017933:Peripheral Nervous System / Q000473:pathology*