Ependymoma MRI

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Ahmad Al Maradni, M.D. [2]

Brain MRI may be diagnostic of ependymoma. Finding on brain MRI suggestive of ependymoma include large mixed cystic/solid lesion with haemorrhage and fluid which may indicate areas of necrosis.

• T1

• Solid portions of ependymoma typically are isointense to hypointense relative to white matter

• T2

• Hyperintense to white matter
• More reliable in differentiating tumor margins than non-contrast T1-weighted images (but less reliable than contrast enhanced T1)

• T2* (e.g. SWI)

• Foci of blooming from haemorrhage or calcification

• T1 C+ (Gd)

• Enhancement present but heterogeneous
• Enhancement with gadolinium is useful in differentiating tumor from adjacent vasogenic edema and normal brain parenchyma.

• DWI (diffusion weighted MRI)

• Restricted diffusion may be seen in solid components especially in anaplastic tumour
• Diffusion should be interpreted with caution in masses with significant haemorrhage or calcification

• MR Spectroscopy

• Choline peak elevation according to the cellularity of tumor
• N-Acetylaspartate peak reduction
• Elevated choline/creatinine ratio
• Lipid and lactate rise when degeneration occurs

• 
  T1^[1]
• 
  T2^[1]
• 
  FLAIR^[1]
• 
  T1^[1]
• 
  T1 C+^[1]
• 
  DWI^[1]

^{Note:There is a large left frontal mixed cystic/solid lesion, measuring approximately 4x4x5cm in perpendicular dimensions, with intralesional haemorrhage and fluid level which may indicate areas of necrosis. Large surrounding vasogenic edema involving the contralateral hemisphere, and significant mass effect causing almost 2cm midline shift, obstructing the monro foramina resulting moderate non-communicating hydrocephalus.}

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