摘要
目的探讨新宝石能谱成像(GSI)在不同噪声指数(NI)下的扫描方案和常规扫描模式在肾动脉CT血管成像(CTA)中影像质量和辐射剂量的比较研究。方法将120例行肾动脉CTA患者按照扫描方案分成A组、B组、C组和D组,每组30例。A组采用普通扫描模式,B组、C组和D组采用新的GSI扫描模式,但NI值不同(NI=13,15,17)。图像重组采用迭代重组算法(ASiR)2.0。扫描结束后得到各组图像的信噪比(SNR)、对比噪声比(CNR)、主观评分值及辐射剂量值均值。分别对4组图像的SNR、CNR进行重复测量方差分析(ANOVA)和非参数检验,对主观评分值、辐射剂量均值进行单因素方差分析(one-way ANOVA)。结果 A组图像的SNR、CNR及主观评分值低于B组、C组和D组(P<0.01),B组、C组和D组的图像质量均无统计学差异(P>0.05)。D组的有效剂量(ED)较A组和B组分别降低47.81%和18.59%(P<0.01)。结论新GSI结合不同NI在保证影像质量的同时能大大降低患者的辐射剂量。
Objective The objective of our study was to compare the image quality and radiation dose of computed tomography angiography（ CTA） of the kidney in patients with different body mass indexes using routine CT and the latest Gemstone Spectral Imaging（ GSI） combination of different noise indexes（ NI） with the adaptive statistical iterative reconstruction 2. 0 algorithm（ ASiR 2. 0）. Methods A total of 120 patients who had undergone a CTA of the kidney were divided into four groups（ A,B,C and D）,with 30 patients in each group. Group A underwent a routine CT examination,while groups B,C and D underwent GSI with different noise indexes（ NI = 13,15,17）. All images were restructured using ASiR 2. 0. The signal-to-noise ratio（ SNR） and contrast-to-noise ratio（ CNR） of all images were calculated when the kidney CTA was completed. Each subjective image evaluation used a 5-point scoring method and was conducted by two independent radiologists. The CT dose index of volume（ CTDIvol） and dose-length product（ DLP） were recorded,and the mean value was calculated. The DLP was converted to the effective dose（ ED）. All data were compared with one-way ANOVA. Results The SNR,CNR and subjective image quality in group A were significantly lower than in groups B,C and D（ P〈0. 01）. There were no significant differences in SNR,CNR and subjective image quality among groups B,C and D. The ED of group D decreased by 47. 81% and 18. 59% relative to groups A and B,respectively（ P〈0. 01）. Conclusion The latest GSI with different NI values can more effectively reduce the radiation dose than can the routine CT scan mode for a kidney CTA while still maintaining diagnostic image quality.
出处
《临床放射学杂志》
CSCD
北大核心
2017年第12期1862-1867,共6页
Journal of Clinical Radiology
基金
国家级大学生创新创业项目基金(编号:201710075085)
河北省政府资助临床医学优秀人才培养和基础课题研究项目计划基金(编号:361007)
河北大学附属医院青年基金(编号:2015Q002
2015Q017)
关键词
宝石能谱成像
噪声指数
辐射剂量
影像质量
肾动脉CTA
Gemstone Spectral Imaging
Noise Index
Radiation dose
Image quality
CT angiography of the kidney
