MRI
Axial T1
Axial T2
Axial FLAIR
Axial DWI
Axial T1 C+
Coronal T1 C+
Sagittal T1 C+
Large cystic lesion occpying and expanding the 3rd ventricle and obstructing the foramina of Monro with the shunt tube seen to decompress the ventricles. The cyst contains fluid that is higher than CSF on signal in T1, lower than CSF signal on T2 and hyperintense signal on FLAIR. Another component is seen invaginating into the frontal horn of right lateral ventricle is seen with low signal on FLAIR. Minimal enhancement of cyst wall with no nodules or septations.
Diagnosis: Colloid cyst (pathology proved)