A CT scan gives excellent detail about the bones, however in the case of the spine, the nerves to the arms or legs can often be pinched by soft disc ruptures or overgrowth of spinal ligaments. In such cases, your surgeon may ask the radiologist to administer some dye into the spinal fluid sac with a small needle to better visualize the nerves.
The dye (called contrast) is made with a form of iodine, so be sure to tell us if you have had any problems with iodine or have had a reaction to I.V. contrast dyes in the past. The dye percolates around the nerves so that they show up on the pictures better. The myelogram is often used after prior fusion surgery to see if the bones are healing properly or in cases where more information is needed about your spine. The myelogram itself requires a small needle and local numbing medicine injected in your low back. Most people report that it is not too bad.
The test is performed in a hospital radiology department or in the health care provider’s office by an X-ray technician. You will be asked to lie on the x-ray table and assume various positions. If the X-ray is to determine injury, care will be taken to prevent further injury. The X-ray machine will be positioned over the lumbosacral area of the spine. You will be asked to hold your breath as the picture is taken so that the picture will not be blurry. Usually 3 to 5 pictures are taken.