对比剂稀释给药方案在CCTA中的可行性研究

Feasibility Research of Contrast Media Diluted Administration Regimen in CCTA

目的探讨管电压100 kV条件下冠状动脉计算机断层扫描血管成像(coronary computed tomographic angiography,CCTA)中采取对比剂稀释给药方案的可行性。方法 58例CCTA患者纳入研究,根据对比剂给药方案分为对照组(n=28)和试验组(n=30),对照组采取对比剂(碘佛醇,320 mgI/ml)不稀释静脉给药;试验组采取稀释对比剂给药(碘佛醇与生理盐水以70∶30混合)。对比剂注射速率5 ml/s,用量0.7 ml/kg,两组采取相同扫描参数完成CCTA检查。检查完毕后由两名工作人员采用4分制评分法评价冠状动脉图像质量,分段测量、比较两组冠状动脉血管直径及其CT值。结果两名工作人员对CCTA图像质量的评分一致性较好(Kappa=0.76,P<0.05),两组图像质量评分差异不明显(Z=0.108,P<0.05)。试验组检查中测得最大注射压力为(554.56±12.43)kPa明显小于对照组(815.89±11.4) kPa(t=9.802,P<0.001)。对照组可测量冠状动脉节段共276段,其中包括2 mm≤直径<3 mm的节段119段(400.67±91.24)HU;3 mm≤直径<4 mm的节段97段(500.4±80.39) HU;4 mm≤直径<5 mm的节段51段(552.16±75.11)HU;直径≥5 mm的节段9段(589.89±75.74) HU。试验组可测量冠状动脉节段共308段,其中包括2 mm≤直径<3 mm的节段140段(312.89±58.02)HU;3 mm≤直径<4 mm的节段118段(387.94±75.11)HU;4 mm≤直径<5 mm的节段44段(427.50±75.62)HU;直径≥5 mm的节段6段(482.53±36.14)HU。两组可测量冠状动脉节段分布差异无统计学意义(χ~2=3.126,P>0.05);4个亚组的冠状动脉节段强化幅度对比,其管腔内CT值具有显著的统计学差异(P均<0.01)。试验组中各亚组间血管强化程度的差异均具有统计学意义(P<0.05);对照组4 mm≤直径<5 mm和直径≥5 mm的组间血管强化程度的差异无统计学意义(P=0.243),其他各亚组间血管强化程度的差异具有统计学意义(P均<0.05)。结论在100 kV条件下CCTA检查时采用对比剂稀释给药可以获得强化效果好、质量稳定的冠状动脉图像,并且能够明显降低检查中碘对比剂用量及注射压力。

Objective To explore the feasibility of diluted contrast media in coronary computed tomographic angiography(CCTA)with tube voltage of 100 kV.Methods A total of 58 CCTA patients were enrolled and divided into the control group(n=28)and experimental group(n=30)according to the regimen of contrast agent administration.The patients in control group were injected with undiluted contrast media(Ioversol,320 mg I/ml)intravenously,while the patients in experimental group were injected with dilute contrast media(Iodofol mixed with normal saline at 70∶30).Both injection methods were with a flow rate of 5 ml/s and total dosage of 0.7 ml/kg.The scanning parameters were consistent between the two groups.The coronary images quality was evaluated using a 4-point grading method by two observers.Meanwhile the diameter and intraluminal CT value of the coronary artery were measured and compared between the two groups.Results The scores of CCTA image quality were consistent between the two observers(Kappa=0.76,P<0.05),and there was no significant difference between two groups(Z=0.108,P>0.05).The maximum injection pressure in experimental group was lower than that of control group[(554.56±12.43)kPa vs.(815.89±11.4)kPa,t=9.802,P<0.001].A total of 276 coronary segments were measured in control group,including 119 segments with 2 mm≤diameter<3 mm[(400.67±91.24)HU],97 segments with 3 mm≤diameter<4 mm[(500.4±80.39)HU],51 segments with 4 mm≤diameter<5 mm[(552.16±75.11)HU],9 segments with diameter≥5 mm[(589.89±75.74)HU]and 308 coronary segments in experimental group,including 140 segments with 2 mm≤diameter<3 mm[(312.89±58.02)HU],118 segments with 3 mm≤diameter<4 mm[(387.94±75.11)HU],44 segments with 4 mm≤diameter<5 mm[(427.50±75.62)HU],6 segments with diameter≥5 mm [( 482. 53 ± 36. 14) HU]. The coronary artery segments distribution were no significant differences between the two groups ( χ2 =3. 126,P > 0. 05) ,the intraluminal CT values in different segments of four subgroups were significant differences ( all P <0. 01) . There were significant differences in the degree of vascular enhancement between the subgroups in the experimental group( all P < 0. 05);there was no significant difference in the degree of vascular enhancement between the groups with 4 mm ≤ diameter< 5 mm and diameter ≥ 5 mm in the control group ( P = 0. 243) ,while the degree of vascular enhancement among the othersubgroups were significant differences ( all P < 0. 05) . Conclusion Good coronary artery images can be obtained by dilutedcontrast media in CCTA with tube voltage of 100 kV and the amount of iodine contrast agent and injection pressure also can besignificantly reduced.