Reducing radiation dose in 64-row spiral CT coronary angiography: study based on individualized scan dosage protocol
10.3760/cma.j.issn.1005-1201.2012.03.008
- VernacularTitle:辐射剂量个体化基础上降低64层CT冠状动脉成像扫描剂量的应用研究
- Author:
Deqiang KANG
;
Jing ZHAO
;
Nan PENG
;
Haiqin HUA
;
Chao LI
;
Ying GUO
;
Yun SHEN
- Publication Type:Journal Article
- Keywords:
Radiation dosage;
Coronary angiography;
Tomography;
X-ray computed;
Quality control
- From:
Chinese Journal of Radiology
2012;46(3):234-238
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the methods of reducing radiation dose in CT coronary angiography through optimizing individualized scan dosage protocol.Methods Two hundred patients (group A)underwent coronary CTA examination which was performed with fixed 120 kV and variable mA according to their BMI.The mA was set as 150-300 mA(BMI ＜ 18.5 kg/m2),300-500 mA (18.5 kg/m2 ≤ BMI ＜ 25.0 kg/m2),and 500-800 mA(BMI ≥ 25.0 kg/m2).When all examinations were finished,a linear regression was employed to analyze the correlation between mA and BMI,body surface(Suf),image noise(SD)respectively.The results of the analysis were used to formulate a regression equation,which was further used to establish a table list for quick search on how much mA that individualized coronary CTA scan would need.Another 200 patients(group B)enrolled for the individualized scan were scanned under new protocol that previous study established.The tube voltage was 100 and 120 kV.The tube current was variable according to the data in the table list.One-way ANOVA and Kruskal-wallis H test were used for statistics.Results Regression equation between mA and BMI,Suf,SD was:mA =17.984 × BMI + 169.149 × Suf-2.282 × SD-361.039.The SD(group A:32.08 ± 5.80,group B:28.60±4.47),dose index volume(CTDIvol)[group A:(41.97 ± 11.37)mGy,group B:(33.18±10.07)mGy],effective dose(ED)[group A:(10.91 ±3.07)mSy,group B:(8.83 ±2.72)mSv]had significant differences between the two groups(F =43.45,63.71,49.07 respectively,P ＜0.01 for all).The SD and ED results obtained in group B were better than those in group A.Conclusion Better performances were obtained when BMI combined Suf was used as a new individualized protocol than when BMI was used only,which means good image quality and lower radiation dosage in coronary CTA examination.
