双面屏蔽防护在心脏冠状动脉CT血管成像检查中的辐射防护优化价值

Optimization Value of Double-sided Shielding in Radiation Protection of Cardiac Coronary Artery CT Angiography

目的探讨胸腹前、后非照射部位双面屏蔽防护在心脏冠状动脉CT血管成像(CCTA)检查中的辐射防护优化价值。方法用胸部模型模拟CCTA检查,前瞻性研究胸部模型检查区和检查区之外邻近非检查区分别在胸腹前单面屏蔽防护(单面防护组)以及胸腹前、后双面屏蔽防护(双面防护组)条件下体表(设定测试点并放置热释光剂量计)辐射剂量并进行统计学分析。单面防护组和双面防护组采用相同CCTA技术条件扫描,测试点的辐射剂量由热释光读出器读出辐射剂量当量数值。结果双面防护组CCTA受检者(胸部体模替代)上部非检查区体表测试点(R 3、L 4~6、R 7~9)辐射剂量当量小于单面防护组[(0.730±0.001)mSv比(1.090±0.005)mSv、(1.260±0.002)mSv比(1.610±0.005)mSv、(0.690±0.001)mSv比(0.960±0.009)mSv、(0.839±0.002)mSv比(1.340±0.001)mSv、(0.820±0.009)mSv比(1.009±0.015)mSv、(0.720±0.002)mSv比(0.910±0.008)mSv、(0.350±0.062)mSv比(0.672±0.079)mSv](P<0.05或P<0.01),下部非检查区体表测试点(R 10、L 11~13、R 14~15、X 16)辐射剂量当量小于单面防护组[(0.770±0.002)mSv比(1.230±0.003)mSv、(0.920±0.002)mSv比(1.200±0.004)mSv、(1.090±0.001)mSv比(1.353±0.036)mSv、(0.770±0.002)mSv比(1.360±0.004)mSv、(0.510±0.006)mSv比(0.990±0.000)mSv、(0.570±0.001)mSv比(0.700±0.008)mSv、(0.040±0.002)mSv比(0.080±0.005)mSv](P<0.05或P<0.01),整体测试点辐射剂量当量小于单面防护组(P<0.01)。两组CCTA受检者检查区体表测试点R 1、L 2及整体测试点体表辐射剂量当量比较差异无统计学意义(P>0.05)。结论与胸腹前单面屏蔽防护方式相比,胸腹前、后双面屏蔽防护方式对CCTA的辐射防护更具优化价值。

Objective To discuss the value of double-sided shielding of front and back non-irradiation areas of chest and abdomen in optimizing the radiation protection of cardiac coronary artery CT angiography(CCTA).Methods The chest model was used to simulate CCTA examination,and the radiation dose of the body surface(test points were set and thermoluminescent dosimeter was placed)was prospectively studied in the chest model examination area and the adjacent non-examination area under the conditions of chest and abdomen front single-sided shield protection(single-sided shield group)and chest and abdomen front and back double-sided shield protection(double-sided shield group),respectively,and statistical analysis was conducted.The single-side protection group and double-side protection group were scanned by the same CCTA technology,and the radiation dose equivalent at test points was read out by thermoluminescent reader.Results The radiation dose equivalent of the body surface test points(R 3,L 4-6,R 7-9)in the upper non-examination area of CCTA subjects(chest body model replacement)in the double-sided protection group were lower than those in the single-sided protection group[(0.730±0.001)mSv vs(1.090±0.005)mSv,(1.260±0.002)mSv vs(1.610±0.005)mSv,(0.690±0.001)mSv vs(0.960±0.009)mSv,(0.839±0.002)mSv vs(1.340±0.001)mSv,(0.820±0.009)mSv vs(1.009±0.015)mSv,(0.720±0.002)mSv vs(0.910±0.008)mSv,(0.350±0.062)mSv vs(0.672±0.079)mSv](P<0.05 or P<0.01).The radiation dose equivalent of the body surface test points(R 10,L 11-13,R 14-15,X 16)in the lower non-examination area were less than those of the single-sided protection group[(0.770±0.002)mSv vs(1.230±0.003)mSv,(0.920±0.002)mSv vs(1.200±0.004)mSv,(1.090±0.001)mSv vs(1.353±0.036)mSv,(0.770±0.002)mSv vs(1.360±0.004)mSv,(0.510±0.006)mSv vs(0.990±0.000)mSv,(0.570±0.001)mSv vs(0.700±0.008)mSv,(0.040±0.002)mSv vs(0.080±0.005)mSv](P<0.05 or P<0.01),and the radiation dose equivalent of the overall test points was less than that of the single-sided protection group(P<0.01).There was no significant difference in body surface radiation dose equivalent between the two groups at the body surface test points R 1,L 2 and the whole test point in the examination area of CCTA subjects(P>0.05).Conclusion Compared with the chest and abdomen front single-sided shield,the chest and abdomen front and back double-sided shield has more optimization value for radiation protection of CCTA.