Best Imaging Modality for Meningioma Evaluation
MRI without and with IV contrast is the best imaging modality for evaluating meningiomas, providing superior soft tissue resolution and detailed characterization of tumor features. 1
Primary Imaging Recommendation
MRI without and with IV contrast
- Gold standard for meningioma evaluation due to:
- Excellent spatial resolution and tissue contrast
- Accurate delineation of tumor extent
- Visualization of dural involvement and vascular relationships
- Ability to detect characteristic features:
- Homogeneous dural-based enhancement
- Presence of dural tail
- CSF cleft between tumor and brain
- Intratumoral calcifications (visualized with SWI sequences)
- Vasogenic edema in subjacent parenchyma 1
Characteristic MRI Features of Meningiomas
- T1-weighted images: Typically isointense or hypointense to cortex
- T2-weighted images: Usually hyperintense (signal intensity correlates with histologic subtype)
- Post-contrast: Strong uniform enhancement
- Dural tail sign: Tapering extension along adjacent dura mater 1, 2
Advanced MRI Techniques
MR Perfusion
- Useful adjunct for meningioma evaluation
- Helps in noninvasive grading of meningiomas
- ASL MRI shows potential in grading meningiomas
- DCE MRI characteristics correlate with DOTATATE avidity in higher-grade meningiomas 1
Susceptibility-Weighted Imaging (SWI)
- Better visualization of intratumoral calcifications 2
- Important for surgical planning and differential diagnosis
Additional Imaging Modalities
DOTATATE PET/CT or PET/MRI
- Emerging as valuable adjunct for meningioma evaluation
- Particularly useful for:
- WHO grade 2 and 3 tumors
- Assessment of resection extent
- Response to radiotherapy
- Cases with ambiguous MRI findings 1
- Provides excellent lesion-to-background contrast due to high SSTR expression in meningiomas 1
CT Scanning
- Useful for evaluating calcifications and bony involvement
- Can help identify hyperostosis and bone erosion
- Less sensitive than MRI for soft tissue detail 3
- Not recommended as primary imaging modality unless MRI is contraindicated
Follow-up Imaging Recommendations
- WHO grade 1 tumors: MRI without and with IV contrast every 6-12 months 1, 2
- WHO grade 2 and 3 tumors: More frequent follow-up needed 1
- Post-treatment surveillance: MRI without and with IV contrast is essential to detect residual or recurrent disease 4
Important Considerations
- Red flags for meningioma mimics: Marked T2 hypo- or hyperintensity, absence of dural tail, and dural displacement sign 1
- Brain MRI screening: Should be performed in patients with LAM receiving progestative drugs due to increased risk of meningioma 1
- Post-surgical evaluation: Enhanced MRI significantly improves detection of residual or recurrent meningioma compared to unenhanced imaging alone 4
Pitfalls to Avoid
- Relying solely on unenhanced MRI: While unenhanced MRI can detect many residual tumors (87%), small residues may be missed without contrast 5, 4
- Overlooking dural enhancement patterns: Thick and nodular dural enhancement is suggestive of residual/recurrent meningioma, while thin and smooth enhancement can be seen in patients with or without residual tumor 4
- Misinterpreting signal characteristics: Signal intensity on T2-weighted images correlates with histologic subtype - markedly hypointense tumors typically contain fibroblastic/transitional elements, while markedly hyperintense tumors often have syncytial/angioblastic elements 6
MRI without and with IV contrast remains the cornerstone of meningioma imaging, with advanced techniques like perfusion MRI and DOTATATE PET providing valuable additional information in selected cases.