A myelogram is a specialized diagnostic imaging test used to examine structures within the spinal canal. The procedure combines a spinal injection of a contrast dye with X-rays and computed tomography (CT) scans to highlight the spinal cord, nerve roots, and the surrounding subarachnoid space. This test is typically performed when standard imaging, such as an MRI, does not provide a clear diagnosis for conditions like herniated discs, spinal stenosis, tumors, or nerve root injuries. The contrast material makes soft tissues and nerves visible, allowing doctors to precisely locate pressure or abnormalities.
Preparing for the Myelogram
Preparation for a myelogram involves adjusting certain medications to ensure safety. Your healthcare provider will instruct you to stop taking blood thinners, such as aspirin or warfarin, several days before the test to reduce bleeding risk at the injection site. Some psychiatric medications or muscle relaxants may also need to be temporarily held because they can lower the seizure threshold, a possible side effect of the contrast dye.
You will receive specific instructions regarding food and drink, usually requiring fasting for a few hours before the procedure. It is recommended to significantly increase your intake of clear fluids in the 24 hours leading up to the test. Being well-hydrated helps your body manage the contrast dye and may reduce the chance of developing a post-procedure headache.
Logistical preparation is important for safety following the myelogram. Since you may receive a mild sedative and should not drive for 24 hours, you must arrange for a responsible adult to drive you home. Wear comfortable, non-restrictive clothing and leave all jewelry and valuables at home, as you will likely change into a hospital gown.
Addressing the Primary Concern: Is the Procedure Painful?
The most common concern about a myelogram is the level of discomfort, and patients generally experience more pressure and deep discomfort than sharp pain during the injection phase. The process begins with the injection of a local anesthetic into the skin of your lower back using a fine needle. This initial injection may cause a brief, stinging sensation, but it significantly dulls the feeling for subsequent steps.
Once the skin is numb, the radiologist uses a slender spinal needle to reach the subarachnoid space, which is the area surrounding the spinal cord that contains cerebrospinal fluid. Most people describe the sensation of the spinal needle insertion as an intense feeling of pressure or a deep ache. It is important to remain completely still during this part of the procedure to prevent accidental movement of the needle.
After the needle is positioned correctly, the contrast dye is slowly injected into the spinal fluid. Some individuals may feel a warm sensation spreading down the legs or a momentary twitching of the muscles. While the entire process may be uncomfortable, the medical team works quickly to minimize discomfort. If your anxiety is high, a mild sedative can be administered before the procedure begins to help you relax.
Step-by-Step: What Happens During the Myelogram
The myelogram is typically performed in an imaging suite equipped with a fluoroscope and a CT scanner. The procedure starts with you lying on your stomach or side on a padded examination table. The medical team cleanses the injection area on your back with an antiseptic solution and covers it with sterile drapes to maintain a sterile environment.
Using fluoroscopy, which is a live X-ray video feed, the doctor guides the spinal needle into the correct position between two vertebrae. Fluoroscopy allows the radiologist to see the needle tip in real-time, confirming its precise location in the spinal canal before any fluid exchange occurs. A small amount of cerebrospinal fluid may be withdrawn for lab testing before the contrast dye is injected.
Once the contrast dye is administered, the needle is removed, and the primary imaging phase begins. The examination table is often tilted in various directions to allow gravity to move the contrast agent to different segments of the spine. You may be secured with a brace or harness during this tilting to ensure you remain safely positioned on the table.
After the X-ray images are captured, you will be moved to a CT scanner. The computed tomography scan takes detailed cross-sectional images of the spine, which provide finer detail of the bones and soft tissues. The entire myelogram procedure, including the injection and the subsequent imaging, typically takes about an hour to complete.
Post-Procedure Care and Recovery
Following the myelogram, you will be taken to a recovery area for observation, usually for at least an hour. To prevent a spinal headache, which is caused by a persistent leak of spinal fluid from the puncture site, it is recommended that you lie flat for a specific period, often two to four hours. Keeping your head slightly elevated during this time is also advised to help minimize potential side effects.
Drinking plenty of fluids is strongly encouraged for the rest of the day to help flush the contrast dye from your system and aid the body in replacing the spinal fluid. Consuming caffeinated beverages may also be suggested, as caffeine can help alleviate or prevent a headache. You should avoid strenuous activities, heavy lifting, and excessive bending for at least 24 hours after the procedure.
While mild headaches, nausea, or a backache at the injection site are common and temporary, contact your doctor if certain symptoms develop. These concerning signs include a severe headache that lasts longer than 48 hours or worsens when you stand up, a fever, or new numbness and tingling in your legs. You can usually resume your normal routine, including driving, the day after the myelogram.