Value of ultrasound in the anatomical evaluation of the brachial plexus: correlation with magnetic resonance imaging

Abstract

ObjectiveTo assess the accuracy of ultrasound in the visualization of the brachial plexus and to determine the value of the method in comparison with that of magnetic resonance imaging (MRI).Materials and MethodsThis was an anatomical study of the brachial plexuses of 20 asymptomatic adults (40 plexuses), comparing ultrasound and MRI in terms of their accuracy. In the ultrasound study, a high-frequency linear transducer was used, and a neurovascular coil was used in the MRI study. To estimate the frequency of visualization, the brachial plexus was divided into segments.ResultsThe cervical nerve roots, the upper trunk, and the middle trunk were the segments that were best visualized on ultrasound. On MRI, the degree of visualization was excellent for most of the segments. In the comparison between ultrasound and MRI, the C6, C7, upper trunk, and middle trunk segments showed equivalent degrees of visualization, with a high level of agreement between the two methods. ConclusionIn the brachial plexus, ultrasound can be used in the assessment of the cervical nerve roots, as well as of the upper and middle trunks, although it provides limited visualization of the remaining segments. Ultrasound and MRI showed a high level of agreement for the visualization of the C6, C7, and middle trunk segments.

Top-Ten Tips for Imaging the Brachial Plexus with Ultrasound and MRI

“…This lower part of the brachial plexus is difficult to see clearly. 12 Repositioning the transducer in a longitudinal plane along the line of the vertebral bodies with a slight posterior inclination of the upper part of the transducer, first the vertebral artery can be visualized and more posteriorly the hypoechoic nerve roots exiting the neural foramina. Moving the transducer more laterally, the scalenus muscles can be visualized in the longitudinal plane.…”

Role of ultrasonography in evaluation of post ganglionic brachial plexus injury in correlation with magnetic resonance and intraoperative findings

“…Ventral rami of cervical nerve roots C5-C8, & thoracic nerve roots T1 in aid with C4 and T2 portion forms brachial plexus [1,2] . Brachial plexus injury is reckoned as most serious nerve injury occurring in upper extremities, due to traumatic incidents like motorcycle accidents & neonatal dystocia [3,4] . Injury can be pre-ganglionic (root avulsion), post-ganglionic (rupture or injury in nerve continuity), or an amalgamation of both [5] .…”

“…MRI has been widely advocated as a superior diagnostic modality owing to its properties, such as superior soft tissue characterization, multi-planar imaging, non-invasive nature as well as radiation free imaging [2] . However, MRI has certain limitations such as requirement of posture, lack of dynamic imaging, enclosed space, limited imaging capability (patient positioning) & availability which makes ultrasonography an adjunct/alternative as it is faster, readily available, inexpensive and has no contraindications [4] . Ultrasonography has also been found to be proficient in ascertaining anatomical location of the cervical roots by visualizing course of the roots which later fuse to form trunks in interscalene region [4] .…”

Intra- and Inter-Observer Variability in Sonographic Measurement of the Cervical Nerve Roots of Healthy Volunteers

“…Cervical nerve roots may possess pathological findings due to various systemic diseases, such as trauma, tumoral lesions, entrapment neuropathies, inflammatoryinfectious causes, and secondary to radiation (7,8). Ultrasound (US) and magnetic resonance imaging (MRI) methods can be used to evaluate the cervical nerve roots (9). MRI imaging is superior to the US with higher spatial resolution and high soft-tissue resolution (10).…”