低浓度对比剂低管电压在CTPA成像中的临床应用研究

Application of using low concentration of contrast and low voltage in CTPA

目的探讨利用低浓度对比剂及低管电压进行低剂量CTPA成像的可行性。方法将60例疑似肺栓塞拟行CTPA检查的患者随机分为2组,第1组(低剂量组)选用低浓度对比剂碘克沙醇(270 mg I/m L),采用管电压100 k V;第2组(常规剂量组)选用高浓度对比剂碘普罗胺(370 mg I/m L),采用管电压120 k V,比较2组图像质量、辐射剂量及对比剂用量的差异。结果低剂量组较常规剂量组图像噪声增加,但2组间主观图像质量、CT值、SNR、CNR差异均无统计学意义(P>0.05);常规剂量组及低剂量组的辐射剂量分别为(5.4±0.5)ms V、(3.3±0.3)ms V,2组间差异有统计学意义(P<0.05),低剂量组较常规剂量组辐射剂量降低38.9%。低剂量组与常规剂量组对比剂用量差异无统计学意义(P>0.05),但2组间摄入碘量差异有统计学意义(P<0.05),低剂量组较常规剂量组摄入碘量降低28.4%。结论利用低浓度对比剂碘克沙醇及低管电压进行低剂量CTPA成像,可以在保证图像质量的前提下明显降低患者的辐射剂量及总摄入碘量。

Objective To investigate the feasibility of using low concentration of contrast and low dose vohage to perform com- puted tomography pulmonary angiography （CTPA）. Methods 60 patients scheduled for CTPA were randomly divided into two groups, the first group using iopamidol 270 mgI/ml, with 100 kV,the second group using iopamidol 370 mgI/ml, with 120 kV. The difference of image quality, contrast medium dose and radiation in the two groups were compared. Results The image noise in the low dose group in- creased compared with the conventional dose group,but there was no significant difference between the two group on image quality, CT values, SNR, CNR （ P 〉 0.05 ）. The effective radiation dose for the two groups were （ 5.4 ± 0.5 ） mSv and （ 3.3± 0.3 ） mSv （ P 〈 0.05 ）. Comparing with the conventional dose group, the radiation in low dose group decreased 38.9%. There was no significant differ- ence between the two group on contrast medium dose （ P 〉 0.05 ）, but there was significant difference between the total amount of iodine in two groups （P 〈 0.05 ）, Comparing with the conventional dose group, the total amount of iodine in low dose group decreased 28.4%. Conclusion Low concentration of contrast and low dose voltage to perform CTPA can maintain optimal image quality and substantially reduce radiation doses.