MRI Imaging for 2-Month Headache History
Order an MRI brain without IV contrast AND MRI complete spine without IV contrast to evaluate for both general intracranial pathology and spontaneous intracranial hypotension. 1
Primary Recommendation
The 2024 ACR Appropriateness Criteria explicitly state that for adults with orthostatic headache from suspected spontaneous intracranial hypotension (SIH) without recent spinal intervention, both MRI brain and MRI complete spine are required to assist in localizing a potential CSF leak. 1 Either protocol—without IV contrast alone OR without and with IV contrast—is considered appropriate, but the non-contrast protocol is sufficient for initial evaluation. 1
Rationale for Dual Imaging
Brain MRI Component
- Detects intracranial pathology including masses, hemorrhage, vascular abnormalities, and inflammatory conditions that could cause chronic headaches 2
- Identifies SIH-specific findings such as diffuse pachymeningeal enhancement, brain sagging, subdural fluid collections, engorged venous sinuses, enlarged pituitary gland, or decreased ventricular size 3, 4
- More sensitive than CT for detecting subtle abnormalities including microbleeds, white matter lesions, and focal encephalomalacia 2
Spine MRI Component
- Localizes CSF leak sites, which most commonly occur at the thoracic spine and cervicothoracic junction 3, 5
- Reveals spinal findings of SIH including epidural fluid collections, dural enhancement, dilated epidural veins, enlarged epidural venous plexus, and structural abnormalities like radicular cysts 5, 6
- Essential for treatment planning if epidural blood patch or surgical intervention becomes necessary 5
Contrast Administration Decision
Start with non-contrast protocols for both brain and spine. 1, 2 The ACR guidelines indicate that contrast is not necessary for initial evaluation of suspected SIH, and there is no relevant literature supporting routine contrast use in this scenario. 2
Consider adding contrast only if:
- Initial non-contrast imaging reveals unexpected findings requiring further characterization 2
- Clinical suspicion exists for infection, neoplasm, or inflammatory conditions 2
- You need to enhance visualization of pachymeningeal enhancement in equivocal SIH cases 3, 4
Clinical Context Considerations
Red Flags Requiring Urgent Imaging
If the patient exhibits any of these features, imaging becomes more urgent:
- Progressive worsening of headache severity or frequency 7
- New focal neurological deficits 7
- Altered mental status 7
- Severe refractory headache not responding to treatment 7
- Orthostatic features (headache worse when upright, better when lying down) suggesting SIH 3, 4
Orthostatic Headache Pattern
If the headache has clear orthostatic characteristics (worse upright, better recumbent), this strongly suggests SIH and makes the complete spine imaging particularly important for identifying the leak site. 1, 3, 4
Common Pitfalls to Avoid
- Don't order brain imaging alone when SIH is suspected—you need spine imaging to localize the leak for potential treatment 1
- Don't use CT as initial imaging for chronic headache evaluation—MRI is far more sensitive for the relevant pathology 2
- Don't add contrast routinely—it increases cost, time, and contrast-related risks without established benefit for typical evaluation 2
- Don't assume normal MRI excludes SIH—some patients with documented CSF leaks have normal conventional MRI findings 2, 3
- Don't over-image stable patients—if initial imaging is normal and headaches are stable without red flags, the yield of repeat imaging is extremely low (0.5% for serious findings) 7
Expected Findings and Follow-Up
If Imaging is Normal
- Monitor for red flag symptoms 7
- Consider symptomatic management with NSAIDs or acetaminophen (limit to <15 days/month to prevent medication overuse headache) 7
- Reassess in 2-4 weeks 7
- Repeat imaging (MRI preferred) only if headaches worsen, pattern changes, or new neurological findings emerge 7