Diagnosis of carotid artery occlusion by duplex scanning

This paper reviews 70 patients, with complete occlusion of the internal carotid artery, investigated by duplex scanning. The correlation between the echogenicity of the occlusion (anechogenic, hypoechogenic or hyperechogenic) and the time interval between the ischaemic symptoms and the ultrasonic investigation showed that some occlusions are hypoanechogenic and others hyperechogenic, in spite of the time interval, and consequently the echogenicity of the occlusion cannot be correlated with the time of its formation. Duplex scanning allows a correct diagnosis in almost all cases of carotid artery occlusion by comparison of the morphological and flowmetric data. The 95% sensitivity in 20 cases was explored by digital angiography also. It was concluded that angiography was usually unnecessary to confirm a carotid occlusion and its use could be limited to rare, doubtful, cases and to patients with contralateral stenosis i.e. candidates for surgery.