Myelogram - Purpose, Procedure, Results Interpretation, Normal Values and more

A myelogram is an imaging test used to evaluate the spinal cord, nerve roots, and surrounding structures. By injecting a contrast dye into the spinal canal, the test allows for detailed visualization of the spinal column and helps to diagnose a variety of conditions that affect the spine, such as herniated discs, spinal stenosis, and tumors. The myelogram is a critical diagnostic tool in the management of neurological disorders related to the spine and nervous system.

What is a Myelogram?

A myelogram is a specialized X-ray or CT scan imaging technique used to examine the spinal cord, nerve roots, and surrounding tissues. It involves injecting a contrast dye into the spinal canal to highlight the structures of the spine and spinal cord. This test can help identify issues such as spinal cord compression, nerve root impingement, infections, or tumors.

The procedure provides a clearer and more detailed image than a standard X-ray or MRI, particularly in identifying abnormalities in the spinal canal and vertebral discs. The contrast dye used in the myelogram enhances the X-ray images and helps doctors visualize the soft tissues and nerve structures that might otherwise be hard to detect.

How Does the Myelogram Work?

The myelogram procedure begins with the patient being positioned on an examination table. A local anesthetic is administered to numb the area where the contrast dye will be injected, usually in the lower back (lumbar area) or neck (cervical area). Once the area is numbed, a needle is carefully inserted into the spinal canal, and the contrast dye is injected.

Once the contrast dye has been injected into the spinal canal, X-ray or CT scan images are taken. These images will capture the spinal cord, nerve roots, vertebrae, and any abnormalities caused by issues such as spinal disc herniation, narrowed spinal canals, or tumors. The contrast dye makes it easier to see these structures clearly, providing valuable insights into the condition of the spine.

What Does a Myelogram Show?

A myelogram can provide essential information about the structure and health of the spinal cord and its surrounding tissues. The results can help doctors identify:

• Spinal stenosis (narrowing of the spinal canal)
• Herniated or bulging discs
• Spinal cord compression due to bone spurs or other abnormalities
• Tumors in the spine or spinal cord
• Infections or inflammation around the spinal cord
• Arteriovenous malformations (abnormal blood vessels)

Myelograms are particularly helpful when other imaging tests, like MRI, fail to provide the necessary level of detail, particularly in areas like the spinal canal and vertebral discs.

Why is a Myelogram Performed?

A myelogram is primarily used to diagnose and evaluate spinal disorders that can lead to nerve compression or spinal cord injuries. The test is commonly recommended in the following situations:

• Assessing Spinal Disorders: Herniated or bulging discs can put pressure on the spinal cord or nerve roots. The myelogram helps visualize these issues clearly, allowing doctors to assess the extent of damage.
• Diagnosing Spinal Stenosis: Spinal stenosis refers to the narrowing of the spaces within the spine, which can put pressure on the spinal cord and nerves. A myelogram can help identify areas of narrowing and determine whether they are contributing to symptoms like pain, numbness, or weakness.
• Evaluating Nerve Root Compression: Nerve root compression caused by bulging discs, bone spurs, or arthritis can cause pain or dysfunction. The myelogram allows doctors to assess where the compression occurs and how severe it is.
• Identifying Spinal Cord Abnormalities: Myelograms are helpful in detecting issues such as spinal cord tumors, infections, and cysts that may be difficult to identify with other imaging methods like MRI.
• Monitoring Post-Surgical Changes: For patients who have had spinal surgery, the myelogram can be used to monitor the healing process and identify complications such as scar tissue or new bulging discs.
• Evaluating Unexplained Neurological Symptoms: In patients with unexplained numbness, weakness, or pain in the extremities, a myelogram can help pinpoint the source of the issue and guide treatment.

Normal Range and Interpretation of Myelogram Results

The results of a myelogram are evaluated by a radiologist or specialist in spinal imaging. A normal myelogram would show clear spaces for the spinal cord and nerve roots, with no areas of narrowing, blockage, or abnormal growths.

Abnormal Results:

• Herniated discs: If the contrast dye highlights areas where discs are pushing into the spinal canal or nerve roots, it may indicate a herniated disc.
• Spinal stenosis: Narrowed areas of the spine that compress the spinal cord or nerves can be identified as areas of reduced space in the myelogram images.
• Spinal cord compression: The myelogram can highlight areas where the spinal cord is being compressed by bone spurs, tumors, or swelling.
• Tumors or cysts: Unusual growths that may be affecting the spinal cord or surrounding structures will be visible in the imaging.
• Infections: Areas of inflammation or infection around the spinal cord can also show up clearly in a myelogram.

How to Prepare for a Myelogram

Preparing for a myelogram is straightforward, but certain steps must be followed to ensure a smooth procedure and accurate results:

• Discuss Medications and Health Conditions: Inform your doctor about any medications you are currently taking, especially if they affect blood clotting (such as blood thinners). You may be asked to adjust or temporarily stop taking certain medications before the test.
• Fasting Before the Procedure: You may be asked to fast for several hours before the procedure, particularly if sedation is used during the test. Fasting ensures that your stomach is empty and reduces the risk of complications during the injection of contrast dye.
• Avoid Certain Foods and Drinks: It is recommended to avoid caffeine and alcohol the day before the test, as these substances can affect your nervous system and might interfere with the test results.
• Arrive Early: Plan to arrive early for the procedure so that you have time to complete paperwork, discuss any last-minute questions with the healthcare provider, and receive any necessary instructions.
• Wear Comfortable Clothing: You will likely be asked to change into a hospital gown for the test. Wear comfortable clothes and remove jewelry and other metal objects before the procedure, as these can interfere with the imaging process.

What Happens During a Myelogram?

During the myelogram procedure, the following steps typically take place:

1. Injection of Local Anesthetic: The area where the needle will be inserted (usually in the lower back or neck) is numbed with a local anesthetic to minimize discomfort.
2. Contrast Dye Injection: Once the area is numbed, a needle is inserted into the spinal canal, and contrast dye is injected. You may feel some pressure during this process, but the injection is relatively quick and well-tolerated.
3. X-ray or CT Scan: After the contrast dye is injected, X-ray or CT scan images are taken. You may be asked to change positions slightly during the imaging process to ensure the most comprehensive views of the spinal cord and nerve roots.
4. Post-Procedure Monitoring: After the test is complete, you will be monitored for a short time to ensure that there are no immediate complications from the contrast dye injection. You may be asked to lie down for a brief period to reduce the risk of headaches.

10 Frequently Asked Questions About Myelograms

• What is a myelogram?

  A myelogram is a diagnostic test that uses X-rays or CT scans to visualize the spinal cord, nerve roots, and surrounding structures by injecting contrast dye into the spinal canal.

• Why would I need a myelogram?

  A myelogram is often used to diagnose conditions such as herniated discs, spinal stenosis, tumors, nerve root compression, and other spinal abnormalities.

• What should I expect during the procedure?

  During the myelogram, you will receive a local anesthetic, and a contrast dye will be injected into your spine. You may feel mild pressure during the injection, and the entire process typically takes about 30 to 60 minutes.

• Is a myelogram painful?

  The contrast dye injection may cause a mild pressure sensation, but the procedure is generally not painful. Some people experience mild discomfort or a headache afterward.

• How should I prepare for a myelogram?

  You may need to fast for several hours before the procedure, avoid certain medications, and wear comfortable clothing. It’s important to discuss any medical conditions with your doctor prior to the test.

• Are there any risks associated with a myelogram?

  Risks are generally minimal but may include headaches, infection, or allergic reactions to the contrast dye. Your doctor will take steps to minimize any risks.

• What do the results of a myelogram mean?

  Normal results show a clear and unobstructed spinal canal, while abnormal results can indicate herniated discs, spinal stenosis, tumors, or nerve root compression.

• How long does the recovery process take?

  Recovery from a myelogram is typically quick, with most people able to resume normal activities within 24 hours. It’s important to follow your doctor’s instructions for post-procedure care.

• Can a myelogram help diagnose cancer?

  Yes, a myelogram can help identify spinal tumors and abnormal growths that may indicate cancer or other serious conditions.

• How long does it take to get results from a myelogram?

  Results are usually available within 1 to 2 days after the procedure. Your doctor will review the images and discuss the findings with you.

Conclusion

A myelogram is a powerful and effective tool for diagnosing a variety of spinal conditions, including herniated discs, spinal stenosis, tumors, and nerve root compression. By injecting contrast dye into the spinal canal, the procedure provides detailed images of the spine and surrounding structures, helping doctors pinpoint issues that may be causing back pain, numbness, or weakness.

Preparing for the test, understanding the process, and interpreting the results can help reduce anxiety and ensure you’re fully informed. If you have any concerns about a myelogram, it’s always a good idea to discuss them with your healthcare provider, who can guide you through the process and help determine the best treatment for your condition.