能谱CT门静脉期虚拟平扫替代常规平扫的可行性研究  

Feasibility of replacing conventional scan with virtual non-contrast enhanced CT in portal vein phase

作　　者：王晶 张晓燕 丁少峰 吴静 杨瑞 刘璐 WANG Jing;ZHANG Xiaoyan;DING Shaofeng;WU Jing;YANG Rui;LIU Lu(Department of Radiology,Pingluo people′s Hospital,Pingluo 753400,China)

机构地区：[1]宁夏平罗县人民医院放射科,宁夏平罗753400

出　　处：《宁夏医学杂志》2023年第2期140-142,共3页Ningxia Medical Journal

摘　　要：目的探讨能谱CT门静脉期虚拟平扫替代常规平扫的可行性。方法收集49例腹部增强扫描患者,选用美国GE Revolution128矢量CT宽体探测器螺旋CT,动脉期、门静脉期、延迟期3组采用能谱(GSI)扫描模式,平扫使用常规扫描模式,平扫与门脉期增强均采用前置ASiR-V40%算法重建成层厚及层间距均为1.25 mm的薄层图像传入GE ADW4.7后处理工作站,门静脉期图像经GSI Volume Viewer软件处理得到虚拟平扫图像。根据成像方式组合可分为常规平扫+三期动态增强、虚拟平扫+三期动态增强扫描2种模式。分别测量常规平扫与门静脉期虚拟平扫2种图像肝脏及腹主动脉、竖脊肌的CT值、平均噪声(SD)值、平均信噪比(SNR)值,对图像质量进行客观评价;评价常规平扫与门静脉期虚拟平扫的图像质量和诊断效能差异;对比分析2种扫描模式的总辐射剂量差异。结果门静脉期虚拟平扫与常规平扫肝脏、腹主动脉的平均CT值差别不大;门静脉期虚拟平扫肝脏、腹主动脉的SD值小于常规平扫(P<0.05);肝脏、腹主动脉的SNR值大于常规平扫(P<0.05);虚拟平扫+三期动态增强患者接收辐射剂量比常规平扫+三期动态增强患者接收辐射剂量低约25.6%,2者对比差异有统计学意义(P<0.05)。结论2种模式的图像质量相近,总辐射剂量有明显差异,虚拟平扫+三期动态增强模式较常规平扫+三期动态增强扫描模式的总辐射剂量减少约25.6%,故虚拟平扫具有替代常规平扫进行检查的可行性。Objective To explore the feasibility of virtual non-contrast-enhanced CT(VNC)replacing conventional non-contrast enhanced CT(TNC)in portal vein phase.Methods 49 patients with enhanced abdominal scanning were selected,in which non-spectral scanning mode was used for plain scan,and energy spectrum(GSI)scanning mode was used for arterial phase,portal vein phase and delay phase.Both plain scan and portal vein enhancement were reconstructed by the pre-ASiR-V40%algorithm into thin-layer images with a layer thickness and layer spacing of 1.25mm,which were passed into the post-processing workstation GE ADW4.7 workstation,and the portal vein image was passed through the GSI Volume Viewer to obtain a virtual flat scan image.According to the combination of imaging modality,two modes were divided,TNC with three-phase dynamic enhancement and VNC with three-phase dynamic enhancement scanning.The CT value,mean noise(SD)value,and mean signal-to-noise ratio(SNR)value of the liver,abdominal aorta and erector spinae in the conventional plain scan and virtual plain scan were measured respectively.The image quality and diagnostic efficiency were evaluated.The difference of total radiation dose between the two scanning modes was comparatively analyzed.Results There was no significant difference in the mean CT values of liver and abdomina aorta between VNC and TNC,and the SD values of VNC were smaller than TNC(P<0.05).The SNR values of VNC were greater than TNC(P<0.05).The received radiation dose of the patients with virtual plain scan+phaseⅢdynamic enhancement was about 25.6%lower than that of the patients with conventional plain scan+phaseⅢdynamic enhancement,and the difference was statistically significant(P<0.05).Conclusion The image quality was similar between the two modes,but the total radiation dose has obvious difference,the total radiation dose of VNC with three-phase dynamic enhancement mode is reduced by about 25.6%,so VNC has the feasibility of replacing TNC for examination.

关 键 词：能谱 虚拟平扫 辐射剂量 图像质量 ASiR-V 

分 类 号：R816.5[医药卫生—放射医学]