Abstract:
Peripheral nerves of the lower limb may become entrapped at various points during their anatomical course. While clinical assessment and nerve conduction studies are the mainstay of diagnosis, there are multiple imaging options, specifically ultrasound and magnetic resonance imaging (MRI), which offer important information about the potential cause and location of nerve entrapment that can help guide management. This article overviews the anatomical course of various lower limb nerves, including the sciatic nerve, tibial nerve, medial plantar nerve, lateral plantar nerve, digital nerves, common peroneal nerve, deep peroneal nerve, superficial peroneal nerve, sural nerve, obturator nerve, lateral femoral cutaneous nerve and femoral nerve. The common locations and causes of entrapments for each of the nerves are explained. Common ultrasound and MRI findings of nerve entrapments, direct and indirect, are described, and various examples of the more commonly observed cases of lower limb nerve entrapments are provided.Critical relevance statement This article describes the common sites of lower limb nerve entrapments and their imaging features. It equips radiologists with the knowledge needed to approach the assessment of entrapment neuropathies, which are a critically important cause of pain and functional impairment.Key points• Ultrasound and MRI are commonly used to investigate nerve entrapment syndromes.• Ultrasound findings include nerve hypo-echogenicity, calibre changes and the sonographic Tinel\'s sign.• MRI findings include increased nerve T2 signal, muscle atrophy and denervation oedema.• Imaging can reveal causative lesions, including scarring, masses and anatomical variants.
摘要:
下肢的周围神经可能在其解剖过程中的各个点处被捕获。虽然临床评估和神经传导研究是诊断的主要手段,有多种成像选项,特别是超声和磁共振成像(MRI),这提供了有关神经卡压的潜在原因和位置的重要信息,可以帮助指导管理。本文概述了下肢各种神经的解剖过程,包括坐骨神经,胫神经,足底内侧神经,足底外侧神经,数字神经,腓总神经,腓骨深神经,腓浅神经,腓肠神经,闭孔神经,股外侧皮神经和股神经。解释了每个神经陷入的常见位置和原因。神经卡压的常见超声和MRI表现,直接和间接,被描述,提供了更常见的下肢神经卡压病例的各种例子。关键相关性陈述本文介绍了下肢神经卡压的常见部位及其成像特征。它使放射科医生掌握了评估诱捕性神经病所需的知识,这是疼痛和功能障碍的重要原因。关键点•超声和MRI通常用于研究神经卡压综合征。•超声检查结果包括神经低回声,口径变化和超声波Tinel标志。•MRI检查结果包括神经T2信号增加,肌肉萎缩和去神经支配水肿。•成像可以揭示致病病变,包括疤痕,质量和解剖变异。