7T magnetic resonance neurography-ultrasound fusion for peripheral nerve imaging.

Background We present one patient with an initial diagnosis of Guillain-Barre syndrome (GBS) and one with Charcot-Marie-Tooth disease (CMT) type 1A. Methods Both patients underwent ankle tibial nerve fusion-imaging of high-resolution ultrasound (HRUS) with 7T MR neurography (MRN). Results In GBS, the nerve was enlarged, T2-hyperintense, and showed increased vascularization 21 months after symptom onset. In CMT1A, the enlarged nerve was T2-isointense with normal endoneurial blood flow. Conclusions We demonstrate the utility of 7T-MRN-HRUS-fusion-imaging. In GBS, there was evidence of ongoing inflammation resulting in a changed diagnosis to acute-onset chronic demyelinating polyradiculoneuropathy and maintenance of immunotherapy. By MRN-HRUS-fusion, patients with presumed peripheral axonal degeneration could be shown to display imaging markers associated with peripheral nervous system inflammation. Thus, more accurate identification of a treatable inflammatory component may become possible.