====== Posterior fossa ependymoma MRI ======


===== T1 =====

{{::intracranial_ependymoma_mri_t1.jpg?200|}}

Solid portions of [[intracranial ependymoma]] typically are [[isointense]] to [[hypointense]] relative to [[white matter]] 
((Smith A, Smirniotopoulos J, Horkanyne-Szakaly I. From the Radiologic Pathology Archives: Intraventricular Neoplasms: Radiologic-Pathologic Correlation. Radiographics. 2013;33 (1): 21-43. Radiographics (full text) - doi:10.1148/rg.331125192))
    
===== T2 =====

{{::intracranial_ependymoma_mri_t2.jpg?200|}}

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 hemorrhage or calcification
    
===== T1 C+ (Gd) =====

{{::intracranial_ependymoma_mri_t1c.jpg?200|}}
        
Enhancement present but heterogeneous

[[Enhancement]] with [[gadolinium]] is useful in differentiating tumor from adjacent [[vasogenic edema]] and normal brain [[parenchyma]].

===== DWI/ADC =====


Restricted diffusion may be seen in solid components, especially in anaplastic tumor
        
Diffusion should be interpreted with caution in masses with significant hemorrhage or calcification
    
===== MRS =====

        
Choline peak elevation according to the cellularity of tumor
        
NAA peak reduction
        
Elevated Cho/Cr ratio
        
Lipid and lactate rise when degeneration occurs

Although it is uncommon when compared to tumors like [[medulloblastoma]]s, careful examination of the entire [[neuraxis]] is required to assess for the presence of CSF seeding.