These heavy weighted T2 high-resolution scans of the posterior fossa clearly showing the left superior cerebellar artery indenting the left trigeminal nerve at its inferior surface. No significant discrepancy in girth is seen between the trigeminal nerves on either side.
The left superior cerebellar artery can be traced to its origin from the basilar artery (best demonstrated at the coronal scan). It is seen looping downward and touching the inferior aspect of the trigeminal nerve at its middle segment.