基于体模试验对比研究不同模式下多层螺旋CT冠状动脉成像照射剂量

目的 比较单独采用心电门控电流调控(ECG)和复合采用ECG和Z轴管电流调制和实时角度管电流调制方式结合(EcG＆CAREDose 4D)毫安调制模式下,MSCT冠状动脉成像患者受照剂量的差别.方法 采用体模实验和计算机模拟相结合的方法 针对西门子Somatom Sensation 64层CT冠状动脉成像不同的扫描方式进行实验.测量和估算不同扣描模式下的皮肤峰值剂量、器官剂量和有效剂量,进而对确定性和随机性辐射风险进行分析.结果在保证相同的图像噪声前提下,单独采用ECG模式和复合采用ECG＆CAREDose 4D模式下体模的皮肤峰值剂量分别为:(87.4±0.9)mGy和(45.9±1.2)mGy;有效剂量分别为:17 mSv和10 mSv.复合采用ECG＆CAREDose 4D模式与单独采用ECG模式相比,体模的性腺、红骨髓、肺、胃、乳房、甲状腺各器官受照射剂量分别减少40.0%、36.7%、39.3%、37.7%、38.8%、38.9%.结论与单独采用ECG模式相比,在相同噪声水平下,复合采用ECG＆CAREDose 4D模式可以有效降低体膜皮肤峰值剂量和有效剂量,从而降低确定性辐射效应和随机性辐射效应风险.

Research on comparison of exposure with electrocardiographic gated mA modulation (ECG) and ECG＆CAREDose 4D mode in coronary multi-slice spiral CT angiography

Objective The objective of this article was to compare patients' dose with electrocardiographic gated mA modulation (ECG) and ECG＆CAREDose 4D mode during coronary MSCT angiography.Methods The research was based on phantom experiment and computer simulation to get the mean value of peak skin dose data and effective dose data respectively and to analyze deterministic and stochastic radiation risk.Results The peak skin dose using ECG mode alone and using ECG＆CAREDose 4D mode with the same image noise level was (87.4±0.9) and (45.9 ± 1.2) mGy respectively.Effective dose was 17 and 10 mSy for ECG mode and ECG＆CAREDose 4D mode respectively.Comparing with ECG mode alone, ECG＆CAREDose 4D mode reduced organ dose of gonad, red marrow, lung, stomach, breast and thyroid by 40.0%, 36.7%, 39.3%, 37.7%, 38.8% and 38.9%, respectively. Conclusion Results showed that ECG ＆ CAREDose 4D mode can reduce radiation dose effectively comparing using ECG mode alone, and that ECG ＆ CAREDose 4D mode should be widely applied ehnically with appropriate initial settings.