Learning objectives
The aims of this exhibit are first to recognize normal and abnormal meningeal enhancement in magnetic resonance imaging (MRI) and second to use the patterns of abnormal meningeal enhancementto distinguish different pathologic processes.
Background
The dura mater is also called pachymeninx whereas arachnoid mater and the pia mater are collectively designated as the leptomeninx.
The dura mater is the outermost layer of the meninges.
It consists of an inner meningeal layer and an outer endosteal layer.
The outer layer is the skull’s periosteum and contains vessels and nerves.
It is adherent to the inner surface of the skull and is continuous through cranial sutures and foramina.
The deeper layer is known as the meningeal layer.
This layer is responsible...
Findings and procedure details
Normal meningeal appearance on MRI
-The dura mater may be recognized as a short,
discontinuous,
thin,
hyperintense,
curvilinear structure on contrast-enhanced T1-weighted MRI ( Fig. 2 ).
-The pia mater and the arachnoid mater do not enhance in normal subjects.
-Many factors may affect this appearance such as magnetic power of the machine,
the T1 sequences used (spin echo,
gradient echo,
inversion recovery,
magnetization transfer),
the MRI contrast agent dose and the time between injection and the beginning of the sequence.
Abnormal meningeal thickening
Meningeal...
Conclusion
Abnormal meningeal enhancement is a radiological sign of multiple pathologies.
Depending on itstopography and characterization,
correlated with parenchymal signal abnormalities,
clinical and paraclinical setting,
it may leadto an appropriate diagnosis
References
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Normal and abnormal meningeal enhancement: MRI features.
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Magnetic resonance imaging of normal meningeal enhancement at 1.5 T.
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