低管电压联合低碘对比剂在CTPA中的可行性研究

Feasibility study of low tube voltage and low contrast agent iodine intake in CT pulmonary angiography

目的探讨低管电压联合低碘对比剂在CT肺动脉成像(CTPA)中的可行性。方法连续收集行CTPA的受检者100例,采用随机数字表法分为实验组和对照组。实验组男27例,女23例,年龄31~77岁,平均(55.1±8.4)岁,管电压80 kV,碘海醇30 mL(含碘300 mg/mL);对照组男24例,女26例,年龄30~72岁,平均(54.3±7.1)岁,管电压100 kV,碘普罗胺30 mL(含碘370 mg/mL)。2组间肺动脉强化CT值、噪声值、信噪比(SNR)、有效剂量(ED)、碘摄入量的比较采用t检验,影像质量评分的比较采用Mann-whitney U检验。结果 2组影像质量评分差异无统计学意义(Z=-0.821,P>0.05)。实验组肺动脉强化CT值、噪声值[(336.6±41.0) HU、(15.0±2.5) HU]明显高于对照组[(301.4±36.2) HU、(10.4±1.5) HU],SNR(23.6±5.8)明显低于对照组(29.1±6.4),差异均有统计学意义(t=1.518、0.660、1.061,均P<0.05)。实验组、对照组ED分别为(1.8±0.2) mSv、(3.9±0.9) m Sv,差异有统计学意义(t=0.461,P<0.05)。实验组碘摄入量(9.0 g)较对照组(11.1g)降低了18.9%。结论低管电压联合低碘对比剂在CTPA中是可行的,能明显降低受检者的辐射剂量和碘摄入量。

Objective To explore the feasibility of low tube voltage and low contrast agent iodine intake in CT pulmonary angiography（CTPA）. Methods In total of 100 patients with CTPA were randomly divided into two groups,experimental group（male n=27, female n=23; age range 31-77 years, mean 55.1±8.4 years） was scanned using 80 kV and30 mL of iohexol（300 mgI/mL）, control group（male n=24, female n=26; age range 30-72 years, mean 54.3±7.1 years） was scanned using 100 k V and 30 mL of iopromide（370 mgI/mL）. The attenuation of enhanced pulmonary artery, image noise,signal-to-noise ratio（SNR）, effective dose（ED）, and iodine intake were compared by t test, and subjective score of image quality was compared by Mann-whitney U test between the 2 groups. Results The subjective score did not significantly differ between the 2 groups（Z =-0.821, P〉0.05）. The attenuation of enhanced pulmonary artery and image noise of the experimental group were significantly higher than those of the control group（336.6±41.0 HU vs. 301.4±36.2 HU, t=1.518, P〈0.05; 15.0 ±2.5 HU vs. 10.4 ±1.5 HU, t =0.660, P〈0.05, respectively）. The SNR of the experimental group was significantly lower than that of the control group（23.6 ±5.8 vs. 29.1±6.4, t =1.061, P〈0.05）. The ED of the experimental group and the control group were 1.8±0.2 mSv, 3.9±0.9 mSv, respectively, and the difference was statistically significant（t=0.461, P〈0.05）.The iodine intake of the experimental group（9.0 g） was lower than that of the control group（11.1 g） up to 18.9%.Conclusion Low tube voltage combined with low contrast agent iodine intake is feasible in CTPA, it can significantly reduce the patient＇s radiation dose and iodine intake.