Atherosclerotic Stenosis And Occlusion Of Cerebrovascular: Studied With Multi-slice Computed Tomography Angiography

Objective:To evaluate the clinical value of multi-slice CT angiography(MSCTA) to diagnosis cerebrovascular stenosis and occlusion compared with digital subtraction angiography(DSA).Materials and Methods:46 patients underwent MSCTA and DSA for suspected cerebrovascular atherosclerosis.Select patients according to the inclusion and exclusion criteria.22 arterial segments MSCTA and DSA images of every patient who was included the study will be reviewed and evaluated by two radiologists independently.The MSCTA and DSA images were reviewed prospectively for presence and location of the stenosis and occlusion,and distinguished characterization of plaque which include the calcified,noncalcified and ulcerate plaque.The steonsis rates were calculated and graded,and the narrowest portion of stenosis lumen diameter was measured on both MSCTA and DSA images.The ability of 16 and 64-slice CT angiography on showing the penetrating branches arise from middle cerebral artery(MCA)M1 segment in sliding-thin-slab(STS)maximum intensity projection(MIP)images were accessed by two radiologists respectively. Calculate the sensitivity,specificity,accuracy,positive and negative predictive value, positive and negative likelihood ratio of MSCTA images for detection of moderate, severe stenosis and occlusion by using the interpretations of DSA as the standard. Compare the statistic significance of MSCTA and DSA in quantification of stenosis ratios and steonsis lumen diameter.And compare the statistic significance of 16 and 64-slice CT angiography in depiction the penetrating branches arise from MCA M1 segment.Results:854 vessel segments from 39 patients were included in this study.A total of 140 diseased vessel segments were identified by MSCTA,31(22.1%)stenoses and 6(4.3%)occlusion locate at internal carotid extracranial segment;and 82(58.6%) stenoses and 21(15.0%)occlusion locate at intracranial segment.The correlation between MSCTA and DSA in diagnose the severity of extracranial carotid stenosis was good(K=0.883).The sensitivity,specificity and accuracy of MSCTA in access moderate stenosis were 89.5%,94.9%,93.6%(P＜0.001);severe stenosis were 90.9%, 98.5%and 97.4%(P＜0.001);occlusion were 100.0%,100.0%and 100.0%(P＜0.001), respectively.The calcified,noncalcified plaque and ulcer of plaque can be depicted on MSCTA images exactly.The correlation between MSCTA and DSA in diagnose the severity of intracranial stenosis was good(K=0.923).The sensitivity,specificity and accuracy of MSCTA in access moderate stenosis were 92.1%,99.2%and 98.7% (P＜0.001);severe stenosis were85.7%,99.6%and 99.1%(P＜0.001);occlusion were 95.5%,100.0%and 99.9%(P＜0.001),respectively.The calcified plaque can be depicted exactly but the noncalcified plaque can't be inspected.The difference between MSCTA and DSA in quantification of moderate and severe steonsis lumen diameter in different location of cerebrovascular had no statistical significance.There was statistic significance between 16 and 64-slice CT angiography in depiction the penetrating branches arise from MCA M1 segment(x~2=9.077,P=0.011).And 64-slice CT angiography is better than 16-slice CT angiography obviously.Conclusion:1.the correlation between MSCTA and DSA in evaluate the presence and location,and in measure the severity of stenosis are good.The overall evaluation standards of MSCTA are higher than the results of previous studies,except the sensitivity of severe stenosis(85.7%)in intracranial arterial segments.MSCTA is a reliable method to evaluate the cerebrovascular stenosis and occlusion.The sensitivity,specificity and accuracy of MSCTA are equal to that of DSA in most cases. 2.In this study,the diameter of moderate and severe stenotic remainder lumen was measured directly.The difference between MSCTA and DSA in quantification of moderate and severe steonsis lumen diameter in different location of cerebrovascular had no statistical significance.3.The calcified,noncalcified and ulcerate plaque within the extracranial carotid and the calcified plaque within the intracranial artery can be depicted on MSCTA images exactly,but the noncalcified plaque can't be inspected within the intracranial artery.Moreover,the dense calcification of intracranial stenotic segments may interfere with the accuracy in measurement of stenotic severity and remainder luminal diameter,even makes the quantification impossible.4.This study evaluates the ability of MSCTA in depiction penetrating branches of intracranial arteries initially.With comparison between 16 and 64-slice CT angiography,reveal that 64-slice CT angiography is better than 16-slice CT angiography in depiction the penetrating branches arise from MCA M1 segment.