During a myelogram, a needle is inserted in the spinal canal so that contrast material can be injected. Once this material has been injected, it will highlight the spinal cord, meninges, and spinal nerve roots. The radiologist or technician will then take several x-ray pictures and may reposition the patient several times to get the best views. After the procedure, patients are observed for 1 to 2 hours and then discharged. Preparation for the procedure includes increasing fluid intake and stopping medications such as antidepressants, blood thinners, and drugs that are used to treat diabetes. Women who may be pregnant should inform their doctor or x-ray technician before going through the test.