2021 Workshop Handout Bundle-Basic US of Upper Limb Nerves

Basic US of Upper Limb Nerves - Shanina

Pdf Summary

This document provides an overview of performing ultrasound imaging of upper limb nerves. The objectives of the workshop are to understand the principles of ultrasound imaging, demonstrate scanning techniques for median and ulnar nerves, and discuss the sonographic findings of common entrapment neuropathies.<br /><br />The document highlights the advantages of ultrasound over MRI for peripheral nerve assessments, including its lower cost, faster scanning time, ability to be performed on patients with contraindications for MRI, real-time assessments, and dynamic testing capabilities. However, it also notes that ultrasound is operator-dependent and requires training to obtain proper scanning technique and interpretation of results.<br /><br />Equipment requirements for performing peripheral nerve ultrasound are discussed, including the need for a linear array high-frequency transducer, with a recommended frequency range of 6-18 MHz for superficial nerves of the upper extremity. Basic image optimization techniques are explained, such as adjusting gain, focus, depth, and frequency.<br /><br />The scanning technique involves identifying the nerve in the short axis near anatomic landmarks, sliding the transducer along the nerve's course, and looking for focal changes in size, shape, and echogenicity. Long axis views can also be obtained to further assess abnormalities. Normal sonographic appearance of peripheral nerves is described, including their fascicular architecture and the presence of accompanying arteries and veins.<br /><br />The document also discusses sonographic findings of abnormal nerves, such as focal enlargement in entrapment neuropathies and diffuse enlargement in hereditary and inflammatory neuropathies. Diagnostic cut-off values for cross-sectional area measurements are provided for median and ulnar nerves in carpal tunnel syndrome and cubital tunnel syndrome, respectively.<br /><br />In conclusion, peripheral nerve ultrasound is an effective tool for evaluating nerve disorders, providing additional anatomic information and facilitating diagnosis and management decisions.

Keywords

ultrasound imaging

upper limb nerves

scanning techniques

common entrapment neuropathies

advantages of ultrasound

operator-dependent

equipment requirements

scanning technique

abnormal nerves

nerve disorders