摘要
目的:探讨根据患者个体差异调整扫描参数,进而降低辐射剂量的方法。方法:131例患者分为2组,常规组(A组)和低剂量组(B组)。A组,61例,采用标准采集方法;B组,70例,采用低剂量采集方法,B组患者均按身体质量指数(BMI)调整管电流和管电压。比较2组的剂量指数(CTDIvol)、有效剂量(DLP,ED)、信噪比(SNR)、噪声比(CNR)和扫描长度。结果:2组患者平均年龄、心率、扫描长度、身高、体质量及身体质量指数(BMI)均没有统计学差异(P>0.05)。2组平均容积CT剂量指数(CTDIvol)分别为:(40.7±6.7)mGy,(24.5±10.8)mGy,t=10.1,P<0.05,有统计学差异;有效剂量(ED)分别为:(9.5±1.6)mSv,(5.5±2.6)mSv,t=10.0,P<0.05有统计学差异,B组辐射剂量较A组降低近45%。信噪比(SNR)分别为(38.9±10.5),(36.0±12.2),t=1.5,P>0.05,没有统计学差异;噪声比(CNR)分别为:(35.0±9.7),(32.2±11.0),t=1.6,P>0.05,没有统计学差异。结论:多层螺旋CT冠状动脉成像,在扫描前以患者心率和体质量指数进行合理分组,采用个体化的扫描参数进行扫描,在保证图像质量的情况下明显降低了患者的辐射剂量。
Objective To evaluate a method to adjust scan parameters individually for reducing radiation dose of muhislice CT coronary angiography. Methods There were 131 cases divided into conventional group（group A） and low dose group （group B） with 61 patients in group A and 70 patients in group B. Standard scan technique was used in group A and dose reduction techniques were employed in group B. Subsequently, group B were scanned with individually adjusted mA and kV according to BMI. CTDIvol, DLP, ED, SNR and CNR in the two groups were evaluated, Results The average age of both groups of patients, heart rate, scan length, height, weight and BMI were no differences（P〉0.05）. The average CTDIvol in group A and group B was （40.7±6.7） mGy and （24.5±10.8） mGy, respectively. There was a statistical difference in CTDIvol between the two groups （t=10.1, P〈0.05）. Effective dose （ED） was （9.5± 1.6） mSv, （5.5±2.6） mSv, respectively. There was a statistical difference in ED between the two groups （t =10.0, P〈0.05）. The radiation dose of group B was lower by 45% than that of group A. SNR was 38.9±10.5 and 36.0±12.2 respectively, with t=1.5 and P〉0.05; CNR was 35.0±9.7 and 32.2±11.0 respectively, with t=1.6 and P〉0.05; there were no differences in SNR and CNR between the two groups. Conclusion Adjusting scanning parameters according to body mass index and heart rate for muhislice CT coronary angiography can reduce the radiation dose while having no influence on the quality of imaging.
出处
《医疗卫生装备》
CAS
2012年第12期60-62,共3页
Chinese Medical Equipment Journal
