From the Guidelines
MRI should be considered in patients with lumbago when there are red flag symptoms, persistent neurological symptoms like radiculopathy that don't improve after 6 weeks of conservative treatment, or when considering surgery or interventional procedures for persistent pain. According to the American College of Radiology Appropriateness Criteria for low back pain, updated in 2021 1, MRI is the initial imaging modality of choice for patients with subacute or chronic low back pain who have failed 6 weeks of conservative therapy and are believed to be candidates for surgery or intervention. The goal of imaging is to identify potential actionable pain generators that could be targeted for intervention or surgery.
When to consider MRI:
- Red flag symptoms suggesting serious underlying pathology, such as cauda equina syndrome, suspected cancer, infection, or immunosuppression 1
- Persistent neurological symptoms like radiculopathy that don't improve after 6 weeks of conservative treatment 1
- Considering surgery or interventional procedures for persistent pain 1
- Patients with subacute or chronic low back pain who have failed 6 weeks of conservative therapy and are believed to be candidates for surgery or intervention 1
For most cases of acute lumbago without these concerning features, conservative management with physical therapy, appropriate pain medications, and activity modification for 4-6 weeks is recommended before imaging. Early MRI in uncomplicated cases doesn't improve outcomes and may lead to unnecessary interventions, as incidental findings unrelated to symptoms are common and can lead to anxiety and unnecessary treatments 1.
From the Research
When to Perform MRI in Lumbago
- MRI is considered for patients with lumbago who have had up to 6 weeks of medical management and physical therapy that resulted in little or no improvement in their back pain 2.
- It is also recommended for those patients presenting with red flags raising suspicion for serious underlying conditions, such as cauda equina syndrome, malignancy, fracture, and infection 2, 3.
- Patients with severe or progressive neurologic deficit on presentation and red flags should be evaluated with MRI 2.
- For patients with chronic low back pain, routine imaging is not recommended but is indicated when red flags are present, there is a neuromuscular deficit, or if pain does not resolve with conservative therapy 4.
- MRI is the diagnostic imaging examination of choice in lumbar spine evaluation of low back pain, however, availability of MRI is limited 5.
- CT shows high values of sensitivity and specificity (>80%) in most of the items evaluated, but sensitivity was low for the evaluation of density of the disc (40%) and for the detection of disc herniation (55%) 5.
Specific Conditions
- For patients with lumbar spinal stenosis, the diagnosis can generally be made based on a clinical history of back and lower extremity pain that is provoked by lumbar extension, relieved by lumbar flexion, and confirmed with cross-sectional imaging, such as computed tomography or magnetic resonance imaging (MRI) 6.
- Surgery appears effective in carefully selected patients with back, buttock, and lower extremity pain who do not improve with conservative management 6.