DE—CTA去骨去硬化斑块MIP图像对血管狭窄程度的评价

Evaluation of internal carotid artery stenosis with maximum intensity projection of dual source bone and hard plaque removals under dual-energy computed tomographic angiography

目的通过与数字减影血管造影（DSA）比较，评价双能计算机体层摄影术血管成像（DE．CTA）诊断颈内动脉狭窄与闭塞的准确性。方法选择北京协和医院放射科自2008年8月至2010年5月行DE-CTA检查的怀疑头颈部动脉粥样硬化患者32例，在DE—CTA检查前或后1d至1月内行DSA检查。依据Fischer分段法将颈内动脉分为6段，采用4分评分系统评价头颈部DE—CTA图像质量，对于DE—CTA不显示为闭塞，以及评分≥3分的血管节段进行血管狭窄程度的评估．比较DE—CTA与DSA对颈内动脉狭窄程度诊断的一致性。结果本组32例患者384段血管，除去闭塞血管19段及带支架血管4段，对361段血管进行图像质量评价，显示评分≥3分血管344段（95％），1分血管17段；DE—CTA诊断轻度、中度、重度狭窄及闭塞的血管节段数分别为322、10、12及19。DSA诊断轻度、中度、重度狭窄及闭塞的血管节段数328、8、8及19。DE—CTA与DSA评价不一致血管6段．DE—CTA显示的狭窄程度均大于DSA。结论DE．CTA能较好去除骨骼与钙化对颈内动脉的影响，与DSA相比具有较高的准确性。

Objective To evaluate the veracity of maximum intensity projection （MIP） of dual source bone and hard plaque removals under dual-energy computed tomographic angiography （DE-CTA） in diagnosis of stenosis of the internal carotid arteries, and compare these results to those of digital subtraction angiography （DSA）. Methods A total of 32 patients suspected as having atherosclerosis in the head and neck, admitted to our hospital from August 2008 to May 2010, were chosen in our study; these patients received DSA before CTA or 1 d to 1 month after CTA. Six anatomical segments were described for each internal carotid artery according to Fischer （1938）; ratings were based on a 1-4 scale for MIP under DE-CTA. Lesions were categorized as mild stenosis （0%-49%）, moderate stenosis （50% -69%）, severe stenosis （70%-99%） and total stenosis （no flow was detected）. Stenosis of internal carotid artery was evaluated based on bone and hard plaque removal MIP images under DE-CTA and DSA. Results Three hundred and eighty-four anatomical segments were divided in all the 32 patients, except for 19 with occlusions and 4 with stent. Imaging quality evaluation of 361 segments indicated that 344 segments （95%） enjoyed scores higher than 3 points and 17 enjoyed 1 point. Mild stenosis, moderate stenosis, severe stenosis and total stenosis were noted in 322, 10, 12 and 19 segments, respectively. Six segments were noted as having different results under DE-CTA and DSA, with higher stenosis degree under DE-CTA. Conclusion DE-CTA has a high negative predictive value for internal carotid stenosis, by decreasing the influence of bone and calcification on carotid artery.