Normal vertebral veins and canal. No contrast.

Normal cervical MRI T1 weighted.

Normal cervical MRI T2 weighted.

Normal cervical myelogram. Contrast was introduced into the theca by a needle, placed between the spines of the lower lumbar vertebrae. This example contains water-soluble contrast. There exist examples, which used iodinated oils. If contrast were left in the spinal canal, there was a risk of thecal irritation and radiologists were trained to use the lowest possible lumbar space so as to remove all or most of the contrast after the examination.