The disadvantages of myelography are important to consider when deciding on an appropriate imaging technique for evaluating spinal abnormalities. While myelography can provide valuable information about the spinal canal and adjacent nerve roots, it does have some limitations.
1. Invasive Procedure: Myelography is an invasive procedure that requires the injection of contrast material into the spinal canal. This can cause discomfort and potential complications, such as headache, nausea, or allergic reactions. It also carries a small risk of infection or damage to the spinal cord or nerve roots.
2. Limited Field of View: Myelography primarily visualizes the spinal canal and the surrounding nerve roots. It does not provide a comprehensive view of structures outside this area. For example, it may not adequately assess abnormalities in the vertebral bodies, intervertebral discs, or soft tissues surrounding the spine. In such cases, complementary imaging techniques like MRI or CT may be more suitable.
3. Inability to Assess Intrinsic Spinal Cord Disease: Myelography is not effective in evaluating intrinsic diseases of the spinal cord itself. Conditions such as spinal cord tumors, demyelinating disorders, or inflammatory conditions within the cord cannot be directly visualized using myelography. MRI is the preferred imaging modality for assessing these types of pathologies.
4. Limited Soft Tissue Contrast: Myelography relies on the use of contrast material to highlight the spinal canal and nerve roots. While this can provide useful information, it may not offer optimal soft tissue contrast compared to MRI. MRI can differentiate between various soft tissues, such as muscles, ligaments, and blood vessels, allowing for a more detailed assessment.
5. Radiation Exposure: In cases where myelography is performed in combination with a CT scan (CT myelography), there is exposure to ionizing radiation. Although the radiation dose is generally low, it is still a consideration, particularly in individuals who require repeated imaging or are more sensitive to radiation, such as pregnant women.
6. Operator Dependence: The quality and interpretation of myelography images can be influenced by the skill and experience of the radiologist performing the procedure. Inadequate injection technique or suboptimal image acquisition may lead to limited or misleading results. It is essential to have experienced personnel to ensure accurate and reliable imaging.
7. Discomfort and Potential Side Effects: Some individuals may experience discomfort during the procedure, including pain or a sensation of pressure during the contrast injection. After the procedure, headache, dizziness, or backache may occur. These side effects are usually temporary but can be bothersome for some patients.
Myelography has several limitations, including its invasive nature, limited field of view, inability to assess intrinsic spinal cord disease, limited soft tissue contrast, radiation exposure (in the case of CT myelography), operator dependence, and potential discomfort or side effects. These factors should be considered when determining the most appropriate imaging modality for each individual case.