Magnetic resonance imaging of obstetrical brachial plexus injuries.

Objective: We reviewed MR imaging in infants with Erb's palsy. The goal was to determine the effectiveness of MR imaging in predicting operative findings for these infants.

Methods: Fifteen patients (mean age: 14.5 months) underwent surgical exploration of the brachial plexus. Preoperative MR imaging was acquired in all patients with a GE (Milwaukee, WI, USA) 1.5-Tesla MRI and correlated with the surgical findings as outlined in the children's operative notes.

Results: Through imaging, the presence of at least one pseudomeningocele was found in 8 of the 15 patients (53.3%) while 3 of the 15 patients (20%) had multiple pseudomeningoceles. Posterior shoulder subluxation was seen in 11 patients (73.3%). Fourteen children(93.3%) had imaging abnormalities consistent with either a reparative neuroma or scar tissue investing plexus elements. We were unable to differentiate between the two with MR imaging. At surgery, scar tissue was found entrapping the C5-C6 roots, upper trunk, and/or lateral and posterior cords in 11 patients (73.3%)while 4 patients had reparative neuromas. Two patients had both entrapment by scar tissue and a reparative neuroma. Either entrapment by scar tissue or neuroma was found in all 15 patients (100%).

Conclusions: MR imaging is an effective tool for demonstrating lesions of the brachial plexus worthy of surgical exploration.