胃癌双能量扫描在分期中的应用

目的 探讨胃癌双能量CT优化图像质量,评估其在胃癌术前分期中的作用.方法 收集临床疑有胃癌的患者55例,行双源双能量腹部增强扫描.测量100 kV、70 keV、120 kV图像病灶动静脉期的CT值,信噪比(SNR)、噪声.选择出最佳水平的图像,并评估此水平图像的术前TNM分期,并和常规120 kV图像相对比.结果 动静脉期70 keV和100 kV图像强化程度均高于120 kV(P＜0.001);动脉期70 keV和120 kV的SNR高于100 kV(P＜0.01),静脉期70 keV的SNR高于120 kV和100 kV(P＜0.01);70 keV和120 kV T分期符合率分别为83.7％、72.1％(P=0.25);120 kV和70 keV N分期符合率分别为62.8％、74.4％ (P＜0.05).结论 双能量CT 70 keV单能图像较常规120 kV优化了图像质量,提高了N分期的符合率.

The value of dual-energy CT in staging for gastric cancers

Objective To explore the image quality of gastric cancer improved by dual-energy CT,and to evaluate the clinical utility in staging gastric cancers.Methods 55 patients suspected gastric cancers were included in the study.Patients underwent dual-phasic scans using dual-energy CT with a dual-source scanner.The relationships image quality parameters in 100 kV,120 kV and 70 keV images were evaluated.Image quality parameters comprised mean density,signal-to noise ratio (SNR) and objective noise.The 120 kV and 70 keV images were compared in TNM staging.Results In arterial and portal phase,the attenuation was significantly higher at 70 keV and 100 kV compared to 120 kV images (P＜0.001).In arterial phase,the SNR were higher at 120 kV and 70 keV in comparison to 100 kV(P＜0.01).In portal phase,the SNR were higher at 70 keV in comparison to 120 kV and 100 kV(P＜0.01).Overall accuracy in assessment of tumor invasion of the gastric wall (T stage) was 83.7％ with 70 keV images and 72.1％ with 120 kV images,this difference was not significant (P=0.25);Overall accuracy for lymph node (N) staging was significantly better with 70 keV images(74.4％) than with 120 kV images(62.8％) (P＜0.05).Conclusion The image quality of gastric cancers using dual-energy CT can be improved by optimizing the energy level.The 70 keV images may be used to improve the N-staging accuracy.