Anatomical validation of the sonographic detection of small nervous structures

INTRODUCTION: 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.

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

METHOD: 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.

RESULT: 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).

CONCLUSION: 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.