In the angiography a notch can often be observed in the anterior superior medial aspect of giant ophthalmic artery aneurysm due to the optic nerve 1).
Try oblique 25º away from injection side, center beam 3-4 cm above lateral aspect of ipsilateral orbital rim, orient x-ray tube in Towne’s view. Try submentovertex view.
1)
Heros RC, Nelson PB, Ojemann RG, Crowell RM, DeBrun G. Large and giant
paraclinoid aneurysms: surgical techniques, complications, and results.
Neurosurgery. 1983 Feb;12(2):153-63. PubMed PMID: 6835497.