MRI of the Brachial Plexus using Esaote G-Scan Brio Low Field Strength MRI
The brachial plexus is the collection of nerve fibers extending between the nerve roots exiting the lower cervical and upper thoracic spine (i.e. C5-T1) and regrouping 4 times before ending as the terminal branches in the axilla. The five nerve roots collect to form three trunks: the upper (C5 & C6); the middle C8 & T1). Each of these three trunks divide into anterior and posterior divisions (6 total) that regroup to form three cords named according to the position of the cord to the subclavian artery. The posterior cord is formed by the posterior divisions of all three trunks. The lateral cord is formed from the anterior divisions of the upper and middle trucks (C5-7) and the medial cords formed bye anterior divisions of the lower cord (C8 & T1).
Optimal MRI imaging of the brachial plexus using low field strength MRI scanners is technique dependent. The brachial plexus can be considered The five nerve roots exist the cervical spine exit the spinal canal through the neural foramina of C5-T1 The roots and three trucks within the scalene muscles are typically examined during the MRI of the cervical spine and are best examined on the axial, coronal and sagittal oblique images (perpendicular to the long axis of the cervical neural foramina).
The MRI of the brachial plexus typically concentrates on the appearance of the divisions, cords and branches in relation to the subclavian. The optimal imaging planes for the brachial plexus are the coronal oblique, axial oblique, and sagittal oblique planes in the long and short axes of the subclavian and axillary segments of the artery around which the are distributed. Esaote G-scan Biro MRI utilizes 2-plane localization so optimal imaging planes can be selected along the long and short axes of the subclavian artery. The imaging planes produce imaging planes along the long axis and short axis of the brachial plexus components.
The first images (1A and 1 B) show the coronal oblique and the axial oblique images through the brachial plexus. The right subclavian artery has fast blood flow and is black. The divisions and cords and branches are the tubular structures alongside the black subclavian (medial segment) and the lateral axillary segment of the artery). Figures 1C and 1D show sagittal oblique images through the brachial plexus and demonstrate the more medial trunks (1C) the more lateral cords (1D). Figure 2A shows a diagrammatic representation of the brachial plexus from an anterior view. Figure 2B shows an anatomic dissection of right brachial plexus.
If the examiner uses carefully designed imaging panes and is meticulous about technique one can obtain quality MRI imaging of the brachial plexus using Esaote G-scan Brio MRI.
Images provided courtesy of Brio San Antonio, San Antonio Texas. www.salubrioMRI.com