不同管电压及噪声指数在双下肢CTA中的应用

目的 研究应用不同的管电压和图像噪声指数并且保证图像质量来降低患者所受的辐射剂量在双下肢CTA中的应用。方法 70例行双下肢CTA血管成像的患者，根据不同身体质量指数分成了两组，分别是对照组以及观察组，管电压分别为100 kV、80 kV，噪声指数分别为15、20。使用GE Light Speed64 VCT机，采用自动管电流调节技术。计算两组患者所受辐射剂量。统计学根据计量资料以（x±s）实行标识，利用t检验方法，根据P < 0.05为差异存在一定的统计学意义。结果 观察组剂量长度乘积（DLP）和有效剂量（ED）均较对照组降低53%，两组间差异有统计学意义（P < 0.05）。结论 根据患者BMI数值，降低管电压和合适的范围之内增加噪声指数，在保证图像质量的前提下，能够更好的减轻病人所受到的辐射剂量。

Application of different tube voltage and noise index in CTA of two lower extremities

Objective To study selecting different tube voltage and image noise index to reduce the radiation dose received by patients in CTA of lower extremities without sacrificing the quality of images. Methods According to different body mass index, seventy patients undergoing CTA with lower limbs were divided into control group and observation group. The tube voltages were 100kV and 80kV, and the noise indexes were 15 and 20, respectively. Use the GE Light Speed64 VCT machine with automatic tube current regulation. Calculate the radiation dose to both groups of patients. Statistical data were measured with (x±s) markers and t test was used. P<0.05 was considered statistically significant. Results The dose length product (DLP) and effective dose (ED) in the observation group were 53% lower than those in the control group. There was a statistically significant difference between the two groups (P<0.05). Conclusion According to the BMI value of the patient, reducing the tube voltage and raising the noise index within the appropriate range can effectively reduce the radiation dose to the patient.