基于胸围的管电流调制技术在冠状动脉CT造影应用的可行性探讨

目的：建立以胸围为参考指标调节冠状动脉CT造影（CTA）成像管电流的函数模型，并探讨其个体化管电流调节模型的临床应用的可行性。方法：连续选取68例以自动管电流调节模式扫描的胸部CT病例，建立胸围与管电流之间的函数模型；再应用其建立的胸围-管电流函数模型对另外的连续64例病例进行冠状动脉CTA成像，对图像质量进行评分，并记录噪声值、管电流、辐射剂量等指标。结果：胸围与管电流之间的函数模型以POW函数拟合度最好（R²=0.691，P<0.05）。应用胸围-管电流函数模型冠状动脉CTA成像的平均图像等级评分为（3.38±0.72）分，噪声值为（31.02±3.97）HU，管电流为（390.63±89.30）mA，CTDI_vol为（34.83±10.72）mGy，DLP为（751.67±175.16）mGy·cm。 结论：以胸围为参考指标调节冠状动脉CTA成像管电流方法，能够较好地实现个体化辐射剂量控制，临床应用具有可行性。

Feasibility of tube current modulation based on the chest circumference in coronary CT angiography

Objective: To establish a function model to modulate the tube current according to the chest circumference at Coronary CTA scan, and to evaluate the feasibility of using the function model individually. Methods: Sixty-eight consecutive patients who underwent thoracic scan with automatic current modulation were studied to establish a function model of tube current and chest circumference. The other 64 consecutive patients underwent coronary CTA scan using the new function model. The image quality was scored, and the noise, tube current and radiation dose were recorded and statistically evaluated. Results: The POW function model was the best one to adjust tuber current to the chest circumference (R²=0.691, P<0.05). The mean image quality score, noise, tube current, radiation dose (CTDI_vol) and dose-length product (DLP) were (3.38±0.72) scores, (31.02±3.97) HU, (390.63±89.30) mA, (34.83±10.72) mGy, (751.67±175.16) mGy·cm, respectively. Conclusions: Tube current modulation based on the chest circumference would be feasible to reduce the radiation dose individually in coronary CT angiography.