关键词: 双源CT双能量扫描, 三维重建, 绝对碘值, 标准化碘值, 虚拟单能量能谱曲线斜率

Abstract: Objective The objective of this study was to determine the lesion range between gastric cancer lesions and normal gastric wall,improve the early diagnosis of gastric cancer rate,distinguish between metastatic lymph nodes and non-metastatic lymph nodes,and accurate N staging by dual-source CT double-energy enhanced scan parameters.Methods The dual energy enhanced scan of patients with preoperative gastric cancer was performed by Siemens Somatom Definition Flash dual-source CT.The collected data were analyzed by Syngo.Via software and reconstructed three-dimensionally to obtain the absolute iodine of gastric cancer,normal gastric wall,metastatic lymph node and non-metastatic lymph node value,standardized iodine value and virtual single energy spectrum curve of the slope to combine with postoperative pathological results.The use of statistical methods was to determine the difference between the post-and preoperation.Results The absolute iodine values(IC)were(3.329±0.812)g/L in the gastric cancer lesion and(64.006±17.450)% for the standard iodine values(NIC).The slope of the virtual single energy spectrum curve was-2.916±1.3227,IC(1.563±0.708)g/L in the normal gastric wall.The NIC were(37.122±16.267)% and-1.621±1.4028 for the slope of the virtual single energy spectrum curve.They were significantly statistical difference(P＜0.05).The IC of metastatic lymph nodes were(2.968± 0.547)g/L,(63.597±14.633)% for the NIC and(-2.532 ± 0.753)for the slope of the virtual single energy spectrum curve.The IC of non-metastatic lymph nodes were(1.465±0.408)g/L,(35.240±14.357)% for the NIC and(-1.378±0.726)for the slope of the virtual single energy spectrum curve.They also had significantly statistical difference(P＜0.05).Conclusion Dual-source CT dual-energy scan combined with three-dimensional reconstruction technique can help to determine the lesion range,improve the diagnostic rate of early gastric cancer,distinguish between metastatic and non-metastatic lymph nodes,and improve the accuracy of N staging.

Key words: Dual-energy of dual-source CT scanning, Three-dimensional reconstruction, IC, NIC, The slope of spectrum curve