Does a Cold or Congestion Affect a Brain MRI?
A cold or nasal congestion does not affect the quality or interpretation of a brain MRI, but it will show incidental sinus abnormalities that are clinically irrelevant and should not be confused with pathology.
Key Clinical Consideration
The critical issue is not whether the MRI can be performed, but rather understanding that sinus abnormalities on brain MRI during an upper respiratory infection are extremely common and do not represent true disease 1.
Expected Incidental Findings During Upper Respiratory Infections
When patients with colds undergo brain MRI, the following incidental findings are normal:
- 68% of symptomatic children with upper respiratory tract infections show significant sinus abnormalities on MRI 1
- 42% of completely healthy children demonstrate sinus abnormalities on MRI 1
- 87% of young adults recovering from a cold show significant maxillary sinus abnormalities on CT 1
- 97% of infants who had a cold within 2 weeks preceding head imaging show sinus abnormalities 1
These findings represent mucosal inflammation and fluid accumulation from viral infection, not bacterial sinusitis or other pathology requiring treatment 1.
Clinical Implications for Brain MRI Interpretation
Radiologists and clinicians must not misinterpret these incidental sinus findings as pathologic when the indication for imaging is neurologic 1. The presence of sinus opacification or mucosal thickening during an active cold:
- Does not indicate bacterial sinusitis unless symptoms persist >10 days without improvement 1
- Does not require treatment or additional imaging 1
- Should not delay or cancel the brain MRI if neurologically indicated 1
When Sinus Findings on Brain MRI Actually Matter
Sinus abnormalities seen on brain MRI become clinically significant only when there are specific concerning features suggesting complications 1:
- Intracranial extension: meningitis, epidural abscess, subdural empyema, cerebritis, or brain abscess 1
- Orbital complications: preseptal cellulitis, orbital cellulitis, subperiosteal abscess 1
- Severe symptoms: high fever with altered mental status, severe headache, focal neurologic signs, cranial nerve palsies 1
In these scenarios, MRI with and without IV contrast has 97% diagnostic accuracy for intracranial complications compared to 87% for CT 1.
Practical Approach
Proceed with the brain MRI as scheduled regardless of cold symptoms 1. The scan quality will not be compromised by nasal congestion 2, 3. Simply document the presence of an active upper respiratory infection in the clinical history so the radiologist can appropriately contextualize any incidental sinus findings 1.
The only scenario requiring MRI delay would be if the patient cannot lie still due to severe coughing or requires sedation but has respiratory compromise 2, 3.
Common Pitfall to Avoid
Do not order sinus-specific imaging or initiate antibiotic therapy based solely on incidental sinus opacification seen on brain MRI in a patient with a recent cold 1. This represents overdiagnosis and overtreatment of normal viral inflammation 1.