64排螺旋CT下肢动脉成像质量控制与评估动脉狭窄的效果研究

目的：探讨影响64排螺旋CT下肢动脉成像质量的各种因素及其消除方法，和其在评估下肢动脉狭窄的效果。方法：选取2007年3月～2009年4月进行64排螺旋CT下肢动脉成像的患者180例，其中有80例在1周内进行了常规下肢动脉造影。将CT下肢动脉成像图像分为6个级别打分，通过得分情况分析出影响64排螺旋CT下肢动脉成像的因素。以常规造影为标准，把动脉狭窄分为〈50％、50％～74％、75％～99％、闭塞4个级别，分析64排螺旋CT下肢动脉成像的灵敏度、特异性。结果：影响64排螺旋CT下肢动脉成像的因素有造影剂（速度／浓度／剂量）、延迟时间、扫描参数（旋转时间／螺距）、血管钙化、重建技术、患者年龄等，64排螺旋CT下肢动脉成像在动脉狭窄〈50％、50％～74％、75％～99％、闭塞的灵敏度、特异性分别为（46．5％、89．2％）、（60．6％、91．8％）、（76．5％、95．4％）、（87．1％、98．3％）。结论：64排螺旋CT下肢动脉成像具有多种重建模式，是一种准确的、非侵袭性的成像技术，其在很大程度上能满足临床要求。

The quality control of 64-slice spiral CT on lower extremity artery imaging and assessment on lower extremity artery stenosis

Objective:To study the various factors in imaging quality of lower extremity artery by 64-slice spiral CT and its elimination approaches,and to assess its diagnostic accuracy on lower extremity arterial stenosis.Methods:180 artery images,from Mar.2007 to Apr.2009,of lower extremity taken by 64-slice spiral CT,were enrolled,of which 80 cases were examined by conventional lower extremity arteriography in a week.The image quality was marked as 6 levels,the impact factors were analyzed through scoring.Conventional angiography was regarded as standard,artery stenosis was graded as <50%,50%～ 74%,75%～ 99% and occlusion,the sensitivity and specificity of 64-slice spiral CT on lower extremity artery image were analyzed.Results:The impact factors of artery images of 64-slice spiral CT were contrast medium(speed /concentration /dosage),delay time,scanning parameters(rotation time /pitch),vascular calcification,reconstruction techniques,patient's age.The sensitivity and specificity of artery stenosis of 64-slice spiral CT on artery imaging of lower extremity were(46.5%,89.2%),(60.6%,91.8%),(76.5%,95.4%),(87.1%,98.3%),respectively.Conclusions:The artery imaging of 64-slice spiral CT on lower extremity possesses varied reconstruction modeling.It is a precise and noninvasive imaging technique,at a large extents,this imaging technique can meet the clinical requirements