A well-defined round-shaped hyperattenuating lesion is seen in the prepontine cistern measuring 16.2 x16.4 mm suggesting a basilar artery aneurysm. No other aneurysm was identified.
Normal appearance of both cerebral hemispheres and the posterior fossa with normal grey/white matter differentiation. No evidence of intra- or extra-axial haemorrhage. No evidence of infarction, mass, brain oedema or midline shift.
A normal ventricular system, basal cistern, Sylvian fissures and convexity sulci.
Impression:
A well-defined oval-shaped hyperattenuating lesion is seen in the course of basilar artery most likely basilar artery aneurysm for further assessment.