A myelogram is an imaging test used to help diagnose and evaluate certain spinal conditions. It employs X-ray technology as well as contrast dye to visualize the vertebrae, spinal cord and spinal nerves as well as the spaces between bones in order to detect such problems as a ruptured disk, spinal stenosis, infection or possibly a spinal tumor. The contrast dye is first injected into the spine near the location to be examined via a lumbar puncture along with X-ray imaging called fluoroscopy that is used to precisely target the right spot. Once the dye has had a chance to spread, new X-rays and a CT scan can take place, with the dye helping to create a clearer picture of the spinal structures. This test is performed at a radiology center or hospital radiology department and takes between a half hour and full hour to complete. Patients are usually instructed to remain lying down with their head raised for a minimum of several hours following this procedure.