DUPLEX SCANNING AND CT ANGIOGRAPHY IN THE DIAGNOSIS OF CAROTID-ARTERYOCCLUSION - A PROSPECTIVE-STUDY

Objectives: Differentiating total occlusion from tight stenosis of the internal carotid artery is crucial with regard to treatment and progn osis. At our institution, the diagnosis of carotid stenosis is based o n duplex scanning. In cases of occlusion, duplex is not reliable, and angiography is performed, thereby increasing morbidity. We tried to de termine whether a combination od duplex scanning and CT angiography (C TA) can replace angiography in the diagnosis of carotid occlusion. Des ign: Prospective study. Materials and methods: From 1995 to 1997, 148 patients were diagnosed as having carotid occlusion by duplex scanning . CTA was performed on all patients. Forty-four patients underwent ang iography and 10 patients were surgically explored. Both procedures wer e considered ''gold standard'' for the diagnosis of occlusion. Results : Arteries found to be occluded by both CTA and duplex scan were confi rmed as occluded by angiography or operation in 95% of the cases (42/4 4). Arteries found to be occluded by duplex but patent by CTA were con firmed as patent in 100% of cases (10/10). CTA has a significantly hig her positive predicting value for diagnosing occlusion than duplex sca n (95% vs. 77%, p value <0.01). Conclusions: Combination of duplex sca nning and CTA is safe and accurate in the diagnosis of carotid occlusi on and can replace angiography in most cases, thereby reducing morbidi ty.