Follow-up evaluation of mass. Evaluate for ventricles history of normal pressure hydrocephalus and mass anterior to pons. Implanted defibrillator. Status post VPS placement Nonenhanced CT of brain:There is revisualization of a left sided extra axial mass in the left cerebellopontine angle with extension across the midline posterior to the clivus. The mass superiorly reaches the dorsum sella. There is subtle mass effect on the pons. There is no detectable in edema of brain parenchyma. On this non-infused study this lesion remains similar in size and density.Findings a brief to represent a meningioma. Fourth ventricle is normal in size and unchanged since prior exam.Images through supratentorial space demonstrated enlargement of supratentorial ventricles with a right sided ventricular catheter. The measurements of lateral ventricles demonstrate a very subtle interval decrease in their size. There is better visualization of subarachnoid space surrounding the knee to high complexity of brain parenchyma compared to prior exam. I suspect a small nonhemorrhagic subdural in these locations. This can be only definitively diagnosed with an MRI examination or a post infused CT of brain. The thickest portion of this collection measures approximately 5 mm.
1.Stable extra-axial left cerebellopontine and prepontine mass to represent a meningioma.2.Slight interval decrease in the size of the supratentorial ventricular system.3.Better visualization of extra-axial CSF in the midpole hypodensity bilateral frontal -- parietal regions which suspect the extra-axial subdural nonhemorrhagic collections.