3 Tesla MRI Imaging of Chronic Inflammatory Demyelinating Mononeuropathy and Polyneuropathy

The purpose of this study was to describe imaging findings of chronic inflammatory demyelinating mononeuropathy (CIDM) and chronic inflammatory demyelinating polyneuropathy (CIDP) on a 3 Tesla MRI.

Imaging findings of 12 consecutive patients with biopsy-proven diagnosis of CIDM and CIDP of major nerves of the upper and/or lower extremities were reviewed. All patients underwent imaging on the 3 Tesla MR scanner (GE Medical Systems). Coils used included torso phased array (4 or 8 channel) and custom phased array coils. All patients had T1, T2, and post-gadolinium T1-weighted images performed in at least two planes.

All patients exhibited similar imaging findings. T2 weighted images demonstrated homogeneous increased T2 signal with uniform, smooth, diffuse enlargement of segments of the affected nerves, with the ability to discern individual enlarged nerve fascicles. Following contrast administration, there was faint, peripheral enhancement. Subclinical radiographic abnormalities were found affecting some nerves, with the ability to discern individual enlarged nerve fascicles.

High resolution 3 Tesla MR imaging of the CIDM and CIDP had characteristic imaging findings. These imaging findings could be very helpful in differentiating CIDM and CIDP from other disease processes that commonly affect peripheral nerves.