In addition, there were multiple punctiform hyperintense lesions in the left
ambient cistern. Left basal vein of Rosenthal was not exhibited in contrast-enhanced magnetic resonance venography [Figure 1].{Figure 1}
A CT scan of the brain showed a small subdural effusion in the frontal and left parietal lobes and a small subarachnoid haemorrhage in the left
ambient cistern. There was no midline shift.
On MRI there is a hypointense mass on T1 and T2 -weighted sequences and it appears hypointense on FS (fat saturated) sequences.14 Most intracranial lipomas occur in the midline in the region of the corpus callosum (45%), the
ambient cistern and suprasellar region (23%).1,6 These lesions are frequently associated with hypogenesis or agenesis of corpus callosum.4 Intracerebral vessels and cranial nerves may cross through the mass.1 Similarly our case showed that anterior cerebral arteries were crossing through the mass and giving its branches within the lipoma, visualized by contrast enhanced MRI images.
CASE 2: SAH in left
ambient cistern, DSA showing Pcom aneurysm.
Almost complete obliteration of the contralateral
ambient cistern was noted in addition to significant (17 mm) shift of the midline structures to the right.
The status of the fourth ventricle and
ambient cisterns predict outcome in moderate and severe traumatic brain injury.
In the case of lesions more than 25 mL, anisocoria, uncal herniation, and asymmetric
ambient cisterns, early surgical evacuation is justified.
