Application value of dual-source CT dual-energy imaging in diagnosis of metastatic lymph nodes of gastric cancer / 实用放射学杂志

ABSTRACT

Objective To investigate the value of standardized iodine concentration and energy spectrum curve of dual-source CT in diagnosis of metastatic lymph nodes of gastric cancer.Methods The clinical data of 60 patients diagnosed as gastric cancer were collected in our hospital.All patients underwent dual-source CT routine abdominal scanning and dual-phase energy spectrum enhancement.According to the pathologic results,the lymph nodes were divided into metastatic and non-metastatic groups.Then the enhanced degree,dual-phase normalized iodine concentration (NIC)were measured and compared between metastatic lymph nodes and non-metastatic lymph nodes.The slope of the energy spectrum curve of metastatic lymph nodes and non-metastatic lymph nodes were calculated by dual-energy software.Results When the enhanced degree was higher than 80 HU,the sensitivity (82.4%)and specificity (78.6%)were higher. The artery-phase NIC values of metastatic lymph node and non-metastatic lymph node were(0.546±0.086)and(0.144±0.077),respectively. The difference was statistically significant (P<0.05).The venous-phase NIC values of metastatic lymph node and non-metastatic lymph nodes were (0.479±0.013)and (0.307±0.082),respectively.The difference was statistically significant (P<0.05).The dual-phase energy spectrum curves of metastatic and non-metastatic lymph nodes were all descending patterns.The difference was obvious at 40-80 keV and minimal at 80-140 keV.The sensitivity of diagnosing metastatic lymph nodes was 83.5%,and the specificity was 85.6%when the arterial curve slope was 6.87.The sensitivity of diagnosing metastatic lymph nodes was 63.6% and the specificity was 96.7%when the venous curve slope was 6.67.Conclusion The multiple parameters provided by dual-source CT dual-energy imaging are helpful to the qualitative and quantitative diagnosis of metastatic lymph nodes in gastric cancer.