Oral Manganese as an MRI Contrast Agent for the Detection of Nociceptive Activity

Kathleen Elizabeth Jacobs¹, Deepak Behera¹, Garry Gold¹, Michael Moseley¹, Jarrett Rosenberg¹, David Yeomans², Sandip Biswal¹

Manganese-enhanced magnetic resonance imaging (MEMRI) is a potentially powerful diagnostic method for identifying neural regions of pain processing for image-guided interventions. Manganese can enter nerves via voltage-gated calcium channels, which are selectively upregulated in pain. We gave manganese by oral gavage to two rat groups: one with spared injury of their sciatic nerves and a sham-operated group. We found that rats with spared nerve injury have increased manganese ion uptake and retention in their nerves compared to the nerves of sham-operated rats as shown by increased MR signal and nerve concentrations. Therefore, manganese can specifically enhance nerves associated with nociception.