低浓度造影剂在标准体质量人群冠状动脉CTA检查中的应用

【目的】探讨低浓度碘对比剂配合低电压的前瞻性心电门控扫描在冠状动脉CT血管造影（CTA）检查中的应用价值。【方法】连续收集体质量指数（BM I）小于24 kg/m2的临床疑诊冠心病者59例，随机分为3组：A组（25例）及B组（14例）分别应用270 mgI/mL及320 mgI/mL的碘对比剂，管电压分别为80 kV和100 kV ，C组（20例）应用370 mgI/mL碘对比剂，管电压为120 kV。三组所有病例均采用心电门控触发序列扫描，有效辐射剂量（ED），测量主动脉根部的平均CT值，并对所有病例的冠状动脉CTA图像质量进行评分。【结果】A组、B组和C组的ED分别为（2．00±0．56）、（2．51±0．52）及（4．17±1．55）mSv，三组间两两比较均有显著性差异（P ＜0．05）。A、B、C组主动脉根部增强程度分别为（486．8±113．980）HU、（407．43±83．63） HU、（439．73±72．12） HU ，经统计分析，仅A、B两组比较有统计学意义（t＝2．28，P ＜0．05）。A组、B组及C组分别显示225个、126个和180个冠脉节段，图像优秀率分别为94．67％、89．68％和95．56％，经统计学分析，B、C比较有统计学意义（χ2值为4．00，P ＜0．05），A、B组和 A、C组比较均无统计学差异（χ2值分别为3．03和0．17，均P＞0．05）。【结论】对标准及低体质量人群应用低浓度碘对比剂同时采用低管电压冠状动脉CTA扫描，能够在获得满足诊断图像质量的前提下，大幅度降低碘注射量及辐射剂量。

Study on the Feasibility of Low Concentration Contrast Medium in Coronary CT Angiography for Standard Body Weight People

[Objective]To explore the value of low concentration iodine contrast medium combined with low voltage in prospective ECG-trigger gated coronary artery CT angiography （CTA） .[Methods] Totally 59 patients [body mass index（BMI）〈24 kg/m2 ] suspected as coronary heart disease were collected continuously and divided into 3 groups randomly .Group A（ n=25） and group B（ n=14） received 270 mgI/mL and 320 mgI/mL contrast medium and 80 kV and 100 kV tube voltage respectively ,while group C（ n = 20） received 370mgI/mL contrast medium and 120 kV tube voltage . Prospective ECG-trigger sequence scan was performed in all patients of 3 groups .The effective radiation dose（ED） was recorded .Mean CT value of aorta root was measured .CTA image quality of all patients was scored .[Results] The ED in group A ,B and C were （2 .00 ± 0 .56） ,（2 .51 ± 0 .52） and （4 .17 ± 1 .55）mSv respectively ,and there were significant differences among 3 groups（ P 〈0 .05） .The enhanced degree of aortic root in group A ,B and C were （486 .8 ± 113 .98） ,（407 .43 ± 83 .63） and （439 .73 ± 72 .12）HU respectively ,and there was significant difference only between group A and group B （ t =2 .28 ,P 〈0 .05） .Group A ,B and C showed 225 ,126 and 126 coronary segments ,respectively .The excellent rate of group A ,B and C were 94 .67% ,89 .68% and 94 .67% respectively ,and there was significant difference between group B and C （χ2= 4 .00 ,P〈0 .05） ,but there was no significant difference between group A and group B or between group A and group C（χ2 = 4 .00 and 0 .17 ,all P 〉0 .05） .[Conclusion] Low concentration iodine contrast medium combined with low tube voltage in coronary artery CTA scan for standard and low body weight people can obtain satisfactory diagnosis image quality and reduce injection dose and ED of iodine obviously .