Axial NECT scans show a cystic mass within the anterior horn of left lateral ventricle with
bowing of the septum pellucidum towards the right. The ventricles are enlarged (L>>R) and are
bordered by a halo of hypodensity.
Axial T2WI & FLAIR and Sagittal T1WIs show that the signal within the left intraventricular
mass follows CSF signal. Again, fluid signal has accumulated around the ventricles, suggestive
of transependymal flow due to increased ventricular pressure. On the sagittal T1WI, the corpus
callosum is elevated and stretched, the optic chiasm and inferior recesses of the third ventricle
are depressed into the suprasellar cisterns, and the mamillo-pontine distance is decreased.
Left & Center: Post contrast Axial and Sagittal T1WIs disclosde an enhancing nodule near the
left foramen of Monroe. The rest of the cystic mass does not enhance.
Right: Axial DWI shows no restriction of diffusion within the mass; rather, there is free
diffusion as in the CSF spaces.
Key words: ct mri infection inflammation dwi hydrocephalus