Introduction: Distinction between near-occlusion and occlusion of the internal carotid artery (ICA) is relevant because patients can benefit from a surgical treatment in the first case. Digital subtraction angiography (DSA) is the best neuroimaging technique for its diagnosis but the possibility of related neurologic complications suggests the use of non-invasive tests. Ultrasound (US) and magnetic resonance angiography (MRA) have been proposed as alternative techniques of diagnosis. But these can provoke an erroneous diagnosis when a near occlusion of ICA is present. Multislice helicoidal computed tomographic angiography (MHCTA) can play a role in these situations.
Case reports: Case 1: patient diagnosed of occlusion of the left ICA by cervical US. Cerebral magnetic resonance suggested severe stenosis of intracavernous ICA. MHTCA showed carotid permeability. Case 2: patient diagnosed by cervical US of near occlusion and of occlusion/pseudoocclusion by enhanced RMA. MHCTA showed filiform patency of the cervical ICA. Case 3: a cervical US diagnosed moderate stenosis of the right ICA and severe of the left. Transcranial Doppler suggested near occlusion of the right ICA. MHTCA confirmed near occlusion of the right ICA.
Conclusion: MHCTA correctly diagnosed near occlusion in three patients in which minimally invasive techniques had discrepancies. MHTCA is a new diagnostic technique whose lack of dependence of flow makes a good alternative to confirm findings of US of the cervical ICA.