The value of dual-energy CT in staging for gastric cancers / 实用放射学杂志

ABSTRACT

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.