Figure 1: Pre-operative contrast-enhanced CT head showing a patent right carotid artery. CT scan also shows a well-circumscribed pituitary tumour measuring 3.3 x 4.3 x 3.9 cm with suprasellar extensions and marked elevation of the chiasmatic tissue. The arterial phase imaging demonstrates the right internal carotid artery to have a mildly redundant loop situated at the junction of its precavernous and cavernous segments due to mass effect upon the vessel by the tumour. The radiologist attributed the reduced calibre of the right ICA to possible stenosis. On the left, the ICA is not found to be as significantly displaced as on the right. (a) Sagittal view. (b) Axial view.