7T MRI of Cervical Nerve Root Compression

Neck pain is a common complaint and is often caused by irritation of a nerve root. Most commonly, degeneration of the intervertebral discs or facet joints leads to a narrowing of the neuroforamen, with disc material or bone overgrowth resulting in a compression of the nerve root. In a standard clinical MRI at lower field strengths, the nerve compression is usually not easily visible, and indirect imaging signs are used to obtain the diagnosis. The 7 Tesla (T) MRI at Balgrist Campus makes it possible to acquire images with a substantially higher spatial resolution and to visualize the compressed nerve directly. 

In our recent study, 48 patients with cervical radiculopathy were examined on the 7T MRI scanner before undergoing surgery. All patients also underwent a standard 3T MRI of the cervical spine. We acquired a 3-dimensional DESS (dual-echo steady-state) MRI sequence that we optimized for nerve imaging. It was possible to visualize the anatomy of the cervical nerve roots, the individual nerve rootlets that form each nerve, as well as the dorsal root ganglia with a high resolution. With this technique it was possible at 7T MRI to detect nerve root compressions directly between the vertebrae with a high level of diagnostic confidence, while at 3T MRI the results were insufficient. The 7T MRI examination also allowed a much better correlation between the grade of nerve root compression and patient symptoms of sensory and motor dysfunction. 

The assessment of nerve roots at 7T MRI improves the visualization of nerve root compressions, and our study is a crucial step for the future implementation of high-resolution cervical spine MRI in clinical practice.