Postganglionic lesions of the brachial plexus occur distal to the dorsal root ganglion and can be managed with nerve grafting to provide a better prognosis.  MRI features of post-ganglionic lesions include ^1,2:

• Hypo to isointense appearance of the affected nerve on T1-weighted imaging, hyperintense on T2-weighted imaging
• Nerve fibers appear in discontinuity and distal nerve contraction ball visible if avulsion injury
• Can have direct compression of involvement of nerves by hematoma, fracture fragment, exuberant callus secondary to fracture

 Case courtesy of A/Prof Pramit Phal.