What is the best MRI approach for a patient with worsening low back pain and sciatica unresponsive to anti-inflammatory medications and steroids?

From the Guidelines

For a patient with worsening low back pain and sciatica unresponsive to anti-inflammatory medications and steroids, the best MRI approach would be a lumbar spine MRI without contrast. This non-invasive imaging technique provides detailed visualization of the spinal anatomy, including discs, nerves, and soft tissues that may be causing the symptoms. The protocol should include sagittal and axial T1 and T2-weighted sequences to evaluate disc herniations, spinal stenosis, nerve root compression, and other potential causes of sciatica. Adding fat-suppression sequences can help identify inflammatory changes. Contrast administration is generally unnecessary for initial evaluation unless there are concerns about infection, malignancy, or prior surgery. The MRI should be performed on at least a 1.5 Tesla machine for adequate resolution, and the patient should be positioned supine with knees slightly flexed for comfort. This approach is preferred because it offers superior soft tissue contrast compared to CT scans and can directly visualize nerve root compression, which is often the cause of sciatica that hasn't responded to conservative treatment, as supported by the American College of Radiology Appropriateness Criteria 1.

Some key points to consider when ordering an MRI for a patient with low back pain and sciatica include:

• The presence of red flags, such as a history of cancer, infection, or recent trauma, which may necessitate the use of contrast or alternative imaging modalities 1.
• The patient's prior management and response to conservative treatment, as patients who have not responded to 6 weeks of optimal medical management may be candidates for surgery or intervention 1.
• The potential benefits and limitations of MRI, including its ability to provide detailed visualization of soft tissues and its limitations in detecting certain types of pathology, such as small disc herniations or nerve root compression 1.

Overall, a lumbar spine MRI without contrast is a reasonable initial imaging approach for patients with worsening low back pain and sciatica who have not responded to conservative treatment, as it provides valuable information for guiding further management and treatment decisions, as recommended by the American College of Radiology Appropriateness Criteria 1.

From the Research

MRI Approach for Low Back Pain with Sciatica

• The use of MRI with or without contrast for low back pain with sciatica that is refractory to anti-inflammatory medications and steroids is a topic of ongoing debate 2, 3, 4, 5, 6.
• A study published in 2007 found that imaging can be delayed for at least four to six weeks in patients with nonspecific mechanical low back pain, which usually allows the pain to improve 2.
• Another study published in 2016 investigated if MRI findings identify patients with low back pain or sciatica who respond better to particular interventions, and found that some MRI findings might be effect modifiers for specific interventions, but high-quality trials are needed to determine the clinical importance of MRI findings 3.
• A 2012 study found that there is no support for systemic administration of corticosteroids for low back pain and sciatica, and that local epidural injection can have some short-term benefit 4.
• A systematic review published in 2017 found that MRI findings can change over a period of up to 1 year in patients with low back pain and/or sciatica, but there is a lack of evidence on whether these changes are associated with changes in clinical outcomes 5.
• A randomized controlled trial published in 2003 compared rapid MRI vs radiographs for patients with low back pain, and found that rapid MRI scanning resulted in nearly identical outcomes for primary care patients with low back pain, but may increase the costs of care due to the increased number of spine operations 6.

Key Considerations

• The decision to use MRI with or without contrast should be based on individual patient characteristics and clinical presentation 2, 3, 4, 5, 6.
• MRI findings should be interpreted in the context of clinical symptoms and other diagnostic tests 3, 5.
• The use of corticosteroids for low back pain and sciatica should be carefully considered, and systemic administration should be avoided 4.