Anatomical validation of the sonographic detection of small nervous structures

Ultrasound is a primary imaging modality for diagnosing and managing nerve-related injuries, particularly for identifying peripheral nerve locations. However, its accuracy and reliability in surgical applications remain insufficiently explored, potentially limiting its utility in nerve surgery.

This study aims to assess the precision of ultrasound in identifying upper limb peripheral nerves by comparing ultrasonographic findings with direct human cadaveric dissection.

Fourteen fresh-frozen upper limb specimens were examined in February 2023. Ultrasound assessments were performed by two experienced musculoskeletal radiologists using three linear probes (15 MHz, 24 MHz, and a 22 MHz hockey stick probe). Seven peripheral nerves were identified and marked using dye injections. Subsequent dissections were conducted under loupe magnification by hand surgeons.

The recurrent motor branch of the median nerve exhibited the lowest discrepancy (mean 1.014 ± 1.459 mm) and the highest accuracy (64.29% of specimens). The greatest discrepancy was observed in the branch of the musculocutaneous nerve to the brachialis (mean 5.114 ± 3.758 mm). The interrater correlation coefficient (ICC) varied across nerve sites, ranging from - 6.298 to 0.795, with the highest ICC observed in the superficial branch of the ulnar nerve (0.795, 0.066).

These findings suggest that ultrasound is a valid and effective tool for identifying peripheral nerve branches in the upper limb, particularly for superficial nerves. Improved accuracy in ultrasound-guided nerve identification may enhance surgical precision and reduce complications in nerve-related procedures.