双源CT双能量肝脏虚拟平扫的临床应用

Clinical application of virtual non-contrast scans to liver with dual-source CT in dual-energy mode

目的:研究双源CT双能量虚拟平扫技术在肝脏扫描中的应用价值。方法:对37例上腹部扫描患者行上腹部普通平扫及动脉期、门脉期双能量扫描。通过Liver VNC软件处理后,可以获得动脉期、门脉期虚拟平扫数据,并与普通平扫对比,比较其在平均CT值、信噪比(SNR)、病灶检出率、图像质量及辐射剂量上的差异。结果:虚拟平扫和普通平扫在病灶检出率上无明显差异(P>0.05)。虚拟平扫肝脏CT值高于普通平扫(P<0.05);虚拟平扫图像SNR高于普通平扫(P<0.05)。两组虚拟平扫之间差异无统计学意义(P>0.05)。虚拟平扫的图像质量均可满足临床诊断需求。应用虚拟平扫,可取消普通平扫,辐射剂量可降低34%。结论:双源CT的虚拟平扫技术在保证图像质量的前提下降低了辐射剂量,可取代普通平扫,具有临床应用的潜力。

Objective：To evaluate the diagnostic value of applying virtual non-contrast scanning to liver lesions with dual-source,dual-energy computed tomography（ CT） .Methods：Conventional non-enhanced abdominal CT scanning was performed in 37 patients,followed by scans during the hepatic arterial phase and portal phase with dual-source in dual-energy mode.The images were generated with the built-in liver VNC program for the raw data during the hepatic arterial phase and portal phase in virtual non-contrasted manner,and the previous data were compared with those obtained by conventional non-en-hanced scans regarding the differences of mean CT value,signal-to-noise ratio（SNR）,focal lesions detected,imaging quality and radiation dose.Results：Although the focal lesions detected remained relatively comparable by either virtual or conventional non-contrasted scanning（P〉0.05）,yet the CT Hu values for liver were higher on virtual non-contrast CT images than the conventional counterparts（P〈0.05）,and virtual non-contrast CT also led to better SNR（P〈0.05）.Scans during the hepatic arterial phase and portal phase suggested no difference with the lesions detected（P〉0.05）,and generated sim-ilar diagnostic imaging quality .Virtual non-contrast CT,a substitute for the conventional non-enhanced tomography,was capable of reducing the radiation dose by 34%.Conclusion：Dual-source dual-energy CT may take the place of the conventional non-enhanced CT and be in wider clinical implications ,for it can reduce the level of ionizing radiation by generating favorable imaging quality .