左右肘静脉注射对比剂对CT增强效果的影响

Effect of contrast medium by left or right side ulnar vein injection on the quality of enhanced CT images

目的比较左右肘静脉注射对比剂对CT增强效果的影响。方法选择行胸部平扫加增强CT扫描患者165例，按分层抽样的方法分为青年组（〈40岁）35例、中年组（40～60岁）60例、老年组（〉60岁）70例；按照随机数字表法再分为左肘静脉注射组77例、右肘静脉注射组88例。所有病例均采用多层螺旋CT，扫描范围从肺尖至肺底，注射对比剂后60s进行增强扫描。测量左头臂静脉横跨主动脉弓（或头臂动脉）前方与胸骨柄后缘之间的前后径线，对比分析其前后径线大小与cT增强效果的关系。结果青年组与老年组左头臂静脉横跨主动脉弓（或头臂动脉）前方与胸骨柄后缘之间的前后径线比较差异有统计学意义（P〈O．05），中年组与老年组比较差异无统计学意义（P〉0．05）。左肘静脉注射组和右肘静脉注射组CT值分别为（106±24）、（149±29）HU，两组比较差异有统计学意义（P〈0．05）。左肘静脉注射组图像增强效果好者占61．0％（47／77），右肘静脉注射组图像增强效果好者占79．5％（70／88），两组比较差异有统计学意义（P〈0．05）。结论右肘静脉注射对比剂时，CT增强扫描可避免部分患者因左头臂静脉受压影响图像增强的效果。

Objective To compare the effect of contrast medium by left or right side ulnar vein injection on the quality of enhanced CT images. Methods One hundred and sixty-five consecutive patients underwent thoracic CT contrast enhancement examination with multi-detector CT and scan delay time was 60 seconds. According to group sampling, subjects were divided into three groups： young age group （ 〈 40 years old ） 35 cases, middle age group （40-60 years old ） 60 cases, elder age group（〉 60 years old ） 70 cases, and then patients were divided into two groups by random digits table with left side ulnar vein injection （left vein group, 77 cases ） and right side ulnar vein injection （ right vein group, 88 cases ） . Anteroposterior dimension between posterior border of manubrium sterni and anterior border of aortic arch （or brachioeephalic artery） where left brachiocephalic vein acrossing was measured and analyzed with relation of image quality. Results The anteroposterior dimension showed a statistiea] significant difference between young age group and elder age group（P 〈 0.05 ）, but no statistical difference between middle age group and elder age group（P 〉 0.05 ）. The CT value in left vein group and right vein group was （ 106 ±24 ）, （ 149 ± 29） H U respectively, and there was statistical difference between two groups （P 〈 0.05 ）. The good quality CT image in left vein group and right vein group was 61.0% （47/77）,79.5% （70/88）, and there was statistical difference （P 〈 0.05 ）. Conclusion CT contrast enhancement examinatJion with right ulnar vein injection rather than left side may improve the quality of images by avoiding compression of left braehiocephalic vein in some patients.