From the Guidelines
For radicular back pain, an MRI without contrast is usually the appropriate initial imaging study, as recommended by the American College of Radiology in their 2021 update 1. The use of MRI with contrast is generally not necessary for diagnosing common causes of radicular pain, such as herniated discs or spinal stenosis. However, there are specific situations where contrast may be recommended, including:
- Suspicion of infection, tumor, or other conditions that may require contrast to highlight areas of inflammation or abnormal blood flow
- Prior spinal surgery, where contrast can help evaluate the presence of scar tissue or other post-surgical changes
- Inconclusive results from an initial non-contrast MRI, where contrast may provide additional information to guide diagnosis and treatment According to the American College of Radiology's 2021 update, MRI lumbar spine without IV contrast is usually appropriate as the initial imaging of patients with subacute or chronic LBP with or without radiculopathy and who are candidates for surgery or intervention with persistent or progressive symptoms during or following 6 weeks of optimal medical management 1. It's essential to note that the decision to use contrast should be based on individual patient factors, including medical history, clinical examination findings, and specific symptoms. Patients should inform their healthcare provider about any kidney problems or metal implants that may affect the MRI procedure or the use of contrast agents.
From the Research
Radicular Back Pain and MRI with Contrast
- The use of MRI with contrast for radicular back pain is not explicitly mentioned in the provided studies as a necessary step in diagnosis or treatment 2, 3, 4.
- However, MRI is considered the imaging modality of choice to assess the cause and complicating features of spine pain when conservative treatment fails or worrisome clinical findings are present 3.
- Advanced MRI sequences, such as DWI, DTI, and T2 mapping, can provide useful clinical information in patients with lumbar radiculopathy, potentially indicating active inflammation/myelinic damage and axonal damage/chronicity 5.
- The decision to use MRI with or without contrast should be based on the individual patient's clinical presentation and the presence of signs or symptoms of systemic disease 2.
- There is no clear evidence to suggest that MRI with contrast is necessary for the diagnosis or treatment of radicular back pain, and the use of contrast should be determined on a case-by-case basis 4, 6.
Key Findings
- MRI is useful in identifying systemic disease as a cause of back or limb pain, but systemic disease is rare 2.
- Most back and radiating limb pain is of benign nature, owing to degenerative phenomena 2.
- Imaging findings of disc herniation do not correlate well with clinical presentation or course, and psychosocial factors predict functional disability due to disc herniation better than imaging 2.
- Advanced MRI sequences can detect inflammation and are more predictive of an axial pain generator 2.