Applications of Imaging for Nerve Entrapment at Wrist
摘要
Wrist mononeuropathies, primarily compression neuropathies, result from entrapment of the median, radial sensory, and less frequently, ulnar nerves within narrow anatomical passages, such as the carpal tunnel and Guyon’s canal. Prolonged or severe compression leads to venous congestion and/or ischemia, inflammation, scarring, and demyelination, further impairing nerve function. Diagnostic imaging plays a critical role in the assessment of wrist entrapment neuropathies. Ultrasound (US) and Magnetic Resonance Imaging (MRI) provide superior soft tissue contrast for detailed evaluation of small nerves and their branches. US is particularly useful for assessing entrapment neuropathies, including carpal tunnel syndrome, by identifying changes in nerve size, signal alterations, and fascicular structure. MRI offers additional advantages, including less operator dependence, comprehensive visualization of carpal tunnel contents, and detailed evaluation of associated joint structures, cartilage, and tendons. MR neurography and functional diffusion tensor imaging further allows nerve selective imaging and lesion characterization. After learning from this chapter, the reader will be able to apply these imaging principles in their practices for the benefit of peripheral neuropathy patients.