Spinal neurofibroma. Coloured coronal magnetic resonance imaging (MRI) scan through a neck with a tumour (blue, upper centre) on the spinal cord (purple, running down centre). This kind of benign nerve tumour develops from the fibrous coverings of nerves. It is thus called a neurofibroma. Large tumours may require surgical excision. The spinal cord runs between the protective bony blocks (vertebrae, blue) of the backbone. MRI uses radio waves and magnetic fields to scan the body. A coronal slice is a vertical slice through the human body parallel to the line of the shoulders.