Findings
Sagittal T1-weighted images demonstrate corpus callosum to be intact. No evidence of Chiari malformation. No abnormal pineal region masses. Mild flattening of pituitary gland. Diffusion imaging demonstrates no evidence of recent infarct. Axial FLAIR and T2-weighted images demonstrate multiple white matter hyperintensities involving the juxtacortical, centrum semiovale and periventricular white matter. No evidence of vasogenic edema or mass effect. Large cavum septum pellucidum.
There is a large nonenhancing mass involving the right petrous apex that is increased signal on T1 weighted images. The mass measures approximately 2.5cm x 2.4 cm in the axial dimension and approximately 3cm in the craniocaudad plane. The mass has heterogeneous T2 signal with increased susceptibility within the mass and within its periphery on the gradient echo weighted images. The mass abuts the medial aspect of the petrous portion of the carotid artery but appears to be separate from the vessel. The inferior aspect of the mass extends into the right petroclival fissure. The mass abuts the anterolateral aspect of the right pons in the region of the cisternal segment of the right trigeminal nerve.
Conclusions
Findings are consistent with cholesterol granuloma of the right petrous apex.