Accuracy of Computed Tomography Angiography for Diagnosing Extracranial Mural Lesions in Patients with Acute Internal Carotid Artery Occlusion: Correlation with Digital Subtraction Angiography

Extracranial carotid mural lesions (CML), caused by atherosclerosis or dissection, are frequently observed in acute internal carotid artery (ICA) occlusion, often requiring angioplasty or stenting. This study aimed to assess the diagnostic accuracy of computed tomography angiography (CTA) in differentiating extracranial CML from thromboembolic etiology in acute ICA occlusion in patients eligible for endovascular treatment. Two neuroradiologists retrospectively studied patients with apparent extracranial ICA occlusion on CTA. Patients were divided into two groups: thromboembolism and CML, based on findings from CTA and digital subtraction angiography (DSA). CTA sensitivity and specificity were calculated using DSA as the gold standard. Occlusive patterns and cervical segment widening were evaluated for atherosclerosis, dissection, and thromboembolism etiologies. CTA had a sensitivity of 84.91% (74.32-95.49%) and a specificity of 95.12% (87.31-100%) in detecting extracranial CML. Atherosclerosis was the most common cause, distinguishable with high accuracy using CTA (p < 0.001). No significant differences were found in occlusive patterns between dissection and thromboembolism (p = 0.568). Cervical segment widening was only observed in dissection cases due to mural hematoma. Conclusions: CTA accurately differentiates extracranial CML from thromboembolic etiology in acute ICA occlusion. The pattern of the occlusion and the artery widening help to establish the location and the etiology of the occlusion.