Supraclinoid Aneurysm (CT/MRI/Ang.)	

Aneurysms of the intracavernous or supraclinoid carotid artery appear as dense sellar or juxtasellar masses on CT imaging, with enhancement following contrast administration. However, differentiation from a true neoplasm is often difficult. These lesions are also easily identified on conventional MR examination but unlike stationary tissue, rapidly flowing blood produces little signal. Therefore, MR angiography is another technique that can be used to identify aneurysms (Fig. 24.17).

Fig. 24.17 Supraclinoid aneurysm. Multiple studies of the same patient showing a supraclinoid aneurysm of the right internal carotid artery. The middle cerebral arteries are also demonstrated: (a) enhanced CT image; (b) T2-weighted MR image; (c) MR angiogram of similar orientation to (a) and (b), posterior cerebral artenes are also identified; (d) cerebral angiogram.