Findings:
No intra or extra-axial mass lesion or collection is identified. The ventricles and sulcal spaces are within normal limits. The midline structures are normal with no midline shift.
The brain parenchyma is unremarkable.
The vestibular-cochlear apparatus and internal acoustic canals have a normal appearance. No structural cochlear abnormalities.
The facial and vestibulocochlear nerves have a normal appearance, as well as the trigeminal and abducens nerves.
There is a vascular loop of the left AICA, entering and reaching the lateral part of the internal auditory canal.
Fetal origin of the left PCA is noted. The Circle of Willis is otherwise normal without evidence of any aneurysm or stenosis. The dural venous sinuses are unremarkable.
The pituitary gland is normal.
The orbits, paranasal sinuses and mastoid air cells are clear. No bony abnormality is seen.
Conclusion:
AICA (anterior inferior cerebellar artery) loop within the left IAC, extending >50% into the IAC (type III). Otherwise, normal findings.