双能量CT虚拟平扫技术在乳腺癌诊断中的应用价值

Application of dual-energy CT virtual technique in diagnosis of breast cancer

目的探讨双能量CT虚拟平扫(VNC)技术在乳腺癌诊断中的应用价值。方法回顾2019年3月至2020年8月丽水市中心医院经病理检查证实为乳腺癌的患者64例,术前均行常规平扫(TNC)及动、静脉期双能量增强扫描,通过Syngo.via后处理工作站生成VNC图像。由2位医生观察分析TNC及动、静脉期VNC图像病灶形态学特征,并对图像质量进行5分制主观评分,观察者间一致性采用Kappa检验。比较不同扫描时期图像病灶CT值、噪声(SD)、对比噪声比(CNR)、信噪比(SNR)、图像评分、长径及横径,并记录和比较常规模式及VNC模式的有效辐射剂量。结果2位观察者的主观评分具有较好的一致性(Kappa值>0.75)。不同扫描时期图像的病灶形态学特征、主观图像质量评分、长径及横径的差异均无统计学意义(均P>0.05)。动、静脉期VNC图像上病灶CT值均高于TNC(均P<0.05)。此外,VNC图像具有较高的CNR、SNR值和较低的SD,差异均有统计学意义(均P<0.05)。VNC模式有效辐射剂量小于常规模式(P<0.001),约降低了31.44%。结论双能量CT VNC技术可为乳腺癌患者提供与TNC相似的图像质量,且明显减少辐射剂量。

Objective To explore the application value of dual-energy CT virtual non-contrast scan(VNC)in the diagnosis of breast cancer.Methods The clinical and imaging data of 64 patients with breast cancer confirmed by pathology in Lishui Municipal Central Hospital from March 2019 to August 2020 were retrospectively analyzes.All patients underwent routine plain scan and dual-energy enhanced CT scan in the arterial and venous phases before surgery,and the post-processing workstations generated VNC images.Two observers analyzed the morphological characteristics of lesions on conventional plain scan(TNC)and VNC images in the arterial and venous phases,and subjectively scored the image quality on a 5-point scale.The inter-observer agreement was analyzed by Kappa test.The CT value,noise,contrast-to-noise ratio,signal-to-noise ratio,image score,long and transverse diameters of image lesions in the three groups were compared,and the radiation dose was recorded.Results There was a good agreement between the subjective scores of the two observers(kappa value>0.75).There was no statistically significant difference in the morphological characteristics,subjective score,long diameter and transverse diameter of the lesions among the three groups of images(P>0.05).The CT values of the lesions on VNC images were higher than those on TNC(P<0.05),but the differences were<5 Hu.In addition,VNC images had higher CNR,SNR values and lower noise,and the differences were statistically significant(P>0.05).The effective radiation dose in VNC mode was smaller than that in conventional mode(P<0.05),which was about 31.44%lower.Conclusion Dual-energy CT VNC can provide breast cancer patients with image quality similar to TNC with significantly reduced radiation dose.