Screening for carotid atherosclerotic disease:evaluation at multislice computed tomographic angiography and ultrasonography

Objective:To compare multislice computed tomographic(MSCT) angiography with ultrasonography(US) screening for carotid atherosclerotic disease,and to determine the reliability of MS-CTA for evaluation of carotid arterial stenosis. Methods:In 31 patients,62 carotid arteries were analyzed by MS-CTA and US.The intra-arterial digital subtract angiography(DSA) was performed in 4 patients as well.Multiplanar reconstruction(MPR),maximum intensity projection(MIP) and volume-rendered(VR) images were produced for each MS-CTA study.Carotid Arteries were measured on source axial,MPR,MIP and VR images separately.The degree of stenosis in each segmental artery was calculated according to the formula recommended by NASCET and ECST.Each segmental artery was then graded as no stenosis,mild(0%-29%) stenosis,moderate(30%-69%) stenosis,severe(70%-99%) stenosis,or occlusion. Results:Agreement in diagnosing carotid artery atherosclerosis with both MS-CTA and US was found in 23(37%) of the 62 carotid arteries studied,and the overall agreement of the screening for carotid atherosclerotic disease obtained from two methods was 81%.Agreement on stenosis category among source axial,MPR,MIP and VR images was found in 76(97%) of the 78 segmental arteries studied.Correlation between MS-CTA and DSA was good.Three occlusions were diagnosed correctly by MS-CTA,one of which was not detected by US. Conclusion:MS-CTA and US were significantly correlated in diagnosing carotid artery atherosclerosis,and complementing each other in screening for carotid atherosclerotic disease.Conjointly analyzing the source axial images,MSCT angiography with MPR,MIP and volume-rendering technique(VRT) can be used to adequately evaluate carotid stenosis.