SPIRAL COMPUTED-TOMOGRAPHY - A NOVEL DIAGNOSTIC-APPROACH FOR INVESTIGATION OF THE EXTRACRANIAL CEREBRAL-ARTERIES AND ITS COMPLEMENTARY ROLEIN DUPLEX ULTRASONOGRAPHY

Background-For the detection of atherosclerotic lesions of the extracr anial cerebral arteries, duplex ultrasonography (US) is an established operator-dependent method, whereas arteriography is associated with t he not-insignificant risk of embolic complications. Spiral CT is a pro mising novel diagnostic tool that allows noninvasive, operator-indepen dent diagnosis of obstruction of extracranial cerebral arteries. The a im of our prospective study was to evaluate in a clinical setting the complementary role of duplex US and spiral CT. Methods and Results-We compared the results obtained independently by spiral CT and duplex US in 59 consecutive patients with clinical suspicion of an obstructive lesion affecting the carotid arteries. We analyzed a total of 354 segm ents from the extracranial carotid arteries, including the common, int ernal, and external carotid arteries. A total of 4 complete occlusions , 38 severe stenoses (70% to 99%), and 32 moderate stenoses (30% to 69 %) were concordantly identified by means of duplex US and spiral CT. I n 5 cases in which duplex US did not allow sufficient evaluation of th e carotid artery because of a poor US window or severe calcification, spiral CT allowed identification and correct measurement of the stenot ic lesion. The comparison of the percentage of stenosis with both meth ods was good (r=0.91, P=0.024). Conclusions-Our results indicate that spiral CT of the extracranial cerebral arteries is a promising noninva sive complementary and non-operator-dependent examination. Its applica tion is particularly attractive in cases in which duplex US is not rel iable tie, severe kinking, severe calcification, short neck, and high bifurcation) and particularly when an overall view of the vascular fie ld is required.