双层探测器光谱CT虚拟单能量成像结合对比剂分段注射技术在CT泌尿系造影中的价值  

Optimizing CT urography with dual-layer spectral detector CT virtual monoenergetic imaging and split-bolus contrast protocol

作　　者：赵凡惠 李凯[1,2] 尚海涛 田东东[1,2] 高燕军 ZHAO Fanhui;LI Kai;SHANG Haitao;TIAN Dongdong;GAO Yanjun(Medical Imaging Center,Xi’an No.3 Hospital,Affiliated Hospital of Northwest University,Xi’an 710018,China;Xi’an Key Laboratory of Metabolic Disease Imaging,Xi’an 710018,China)

机构地区：[1]西北大学附属医院/西安市第三医院医学影像学中心,陕西西安710018 [2]西安市代谢性疾病影像学重点实验室,陕西西安710018

出　　处：《中国中西医结合影像学杂志》2025年第2期155-160,共6页Chinese Imaging Journal of Integrated Traditional and Western Medicine

摘　　要：目的:探讨双层探测器光谱CT虚拟单能量成像(VMI)在CT泌尿系造影(CTU)中的临床应用价值。方法:收集行CTU检查的血尿患者92例,随机分为实验组和对照组各46例,实验组先注射对比剂25 mL,15 min后再注射对比剂20 mL和生理盐水30 mL,行皮质-排泄期单期扫描。对照组先行平扫,再注射对比剂100 mL和生理盐水30 mL,后行皮质期、髓质期、排泄期扫描。实验组重建40、50、60、70 keVVMI图像和混合能量图像,对照组排泄期数据重建混合能量图像。采用单因素方差分析比较实验组及对照组图像的CT值、噪声(SD)、SNR和CNR。由2位医师采用5分法进行主观评分,采用Kruskal-WallisH秩和检验比较各组图像质量主观评分的差异。结果:实验组VMI图像CT值、SD、SNR、CNR均随能级的升高而减低,差异均有统计学意义(均P<0.05)。对照组混合能量图像与实验组VMI50 keV图像的SNR、CNR差异均无统计学意义(均P>0.05)。2位医师对图像质量主观评分的一致性较好。实验组VMI50 keV图像显示效果评分最高,VMI40 keV图像对比剂充盈程度评分最高。实验组的有效辐射剂量约为对照组的21.54%。结论:双层探测器光谱CTVMI技术应用于CTU检查可在降低对比剂用量和辐射剂量的同时提高图像质量,VMI40~50 keV为图像显示的最佳能级。Objective:To assess the clinical utility of dual-layer spectral detector CT virtual monoenergetic imaging(VMI)combined with a split-bolus contrast protocol in CT urography(CTU).Methods:Ninety-two patients with hematuria undergoing CTU were randomized into an experimental group(46 cases)and a control group(46 cases).The experimental group received an initial 25 mL contrast bolus,followed by a second bolus of 20 mL contrast and 30 mL saline 15 minutes later,undergoing a single corticomedullary-excretory phase scan.The control group underwent unenhanced scanning followed by 100 mL contrast and 30 mL saline injection,with triphasic(cortical,medullary,excretory)scanning.The experimental group’s images were reconstructed into 40,50,60,70 keV VMI and mixed-energy images,while the control group’s excretory phase images were reconstructed as mixed-energy images.CT values,noise(SD),SNR,and CNR of the two groups were compared via one-way ANOVA.Two radiologists independently scored image quality using the 5-point method,and Kruskal-Wallis H test was used to compare the image quality scores.Results:In the experimental group,VMI images demonstrated a progressive decrease in CT values,SD,SNR,and CNR with increasing energy levels(all P<0.05).No significant differences in SNR or CNR were observed between the mixed-energy images in the control group and the 50 keV VMI images in the experimental group(both P>0.05).Interobserver agreement was excellent.In the experimental group,50 keV VMI images achieved optimal display quality score,while 40 keV VMI images showed superior contrast filling score.The experimental group reduced effective radiation dose to 21.54%of the control group.Conclusions:Dual-layer spectral detector CT VMI with split-bolus protocol enhances CTU image quality while reducing the amount of contrast media and radiation dose,with 40—50 keV VMI providing optimal visualization.

关 键 词：体层摄影术 X线计算机 能谱成像 尿路造影术 造影剂 辐射剂量 图像质量 

分 类 号：R47[医药卫生—护理学]