Xing Jingjing, Chai Yaru, Gao Jianbo, Chen Yan, Dong Junqiang, Yue Songwei
Department of Radiology, the First Affiliatted Hospital of Zhengzhou University, Zhengzhou 450052, China.
Zhonghua Wei Chang Wai Ke Za Zhi. 2016 May;19(5):580-4.
To investigate the application value of spectral CT in the differentiation of stage T3 and T4a gastric carcinoma.
Data of 62 gastric cancer patients of stage T3 and T4a undergoing abdominal spectral CT examination in the First Affiliated Hospital of Zhengzhou University from December 2013 to December 2014 were collected retrospectively. There were 38 male and 24 female patients, with age of 33 to 77(58.6±10.4) years old. Abdominal double-phase enhanced scanning in gemstone spectral imaging mode was used to measure Iodine concentration (IC, 100 μg/ml) and water concentration(WC, 100 μg/ml) of perigastric fat tissue adjacent to the lesion during arterial phase(AP) and venous phase(VP), and normalized iodine concentration (nIC) was calculated respectively(nIC=IC/IC of aorta on the same slice). IC, WC, nIC of arterial phase and venous phase between stage T3 and T4a lesions were compared with double independent sample t test and compared with pathology. The diagnostic efficacy was evaluated using receiver operating characteristic (ROC) curve analysis.
During arterial phase in stage T4a cases, IC (100 μg/ml) was -5.19±0.81 and nIC was -0.05±0.01, which was significantly higher than -3.44±1.54 (P=0.000) and -0.03±0.01 (P=0.000) in stage T3 cases. During venous phase in T4a cases, IC (100 μg/ml) was -3.78±0.94 and nIC was -0.04±0.01, which was significantly higher than -1.62±1.43 (P=0.000) and -0.02±0.02 (P=0.000) in stage T3 cases. As compared to arterial phase, IC and nIC of stage T4a and T3 of venous phase were more significantly different (all P<0.05). WC of stage T4a during arterial and venous phase was 955.72±15.68 and 949.86±17.36 respectively, while WC of stage T3 during arterial and venous phase was 947.77±18.43 and 942.46±18.53 respectively. There were no significant differences in WC between two stage cases during arterial and venous phase (P=0.106, P=0.143). ROC analysis showed that area under the ROC of IC and nIC during arterial phase was 0.829 and 0.867 respectively, and cut-off value of nIC was -0.039 for differentiation of stage T3 and T4a with corresponding 83.3% of sensitivity and 75.0% of specificity; area under the ROC of IC and nIC during venous phase was 0.873 and 0.905 respectively, and cut-off value of nIC was -0.031 for differentiation of stage T3 and T4a with corresponding 81.0% of sensitivity and 85.0% of specificity.
Abdominal spectral CT scan is useful in the differentiation of stage T3 and T4a gastric carcinoma. The IC of perigastric fat tissue is significantly higher in stage T4a gastric carcinoma compared to stage T3 gastric carcinoma. Higher diagnostic efficacy can be obtained when taking -0.031 as the cut-off value of nIC during venous phase.
探讨光谱CT在T3期和T4a期胃癌鉴别诊断中的应用价值。
回顾性收集2013年12月至2014年12月在郑州大学第一附属医院接受腹部光谱CT检查的62例T3期和T4a期胃癌患者的数据。其中男性38例，女性24例，年龄33～77岁（58.6±10.4岁）。采用宝石光谱成像模式进行腹部双期增强扫描，测量病变周围胃周脂肪组织在动脉期（AP）和静脉期（VP）的碘浓度（IC，单位：100 μg/ml）和水浓度（WC，单位：100 μg/ml），并分别计算标准化碘浓度（nIC）（nIC = 病变处IC/同层面主动脉IC）。采用双独立样本t检验比较T3期和T4a期病变动脉期和静脉期的IC、WC、nIC，并与病理结果进行对比。采用受试者操作特征（ROC）曲线分析评估诊断效能。
T4a期病例动脉期IC（单位：100 μg/ml）为-5.19±0.81，nIC为-0.05±0.01，显著高于T3期病例的-3.44±1.54（P = 0.000）和-0.03±0.01（P = 0.000）。T4a期病例静脉期IC（单位：100 μg/ml）为-3.78±0.94，nIC为-0.04±0.01，显著高于T3期病例的-1.62±1.43（P = 0.000）和-0.02±0.02（P = 0.000）。与动脉期相比，T4a期和T3期静脉期的IC和nIC差异更显著（均P<0.05）。T4a期动脉期和静脉期的WC分别为955.72±15.68和949.86±17.36，T3期动脉期和静脉期的WC分别为947.77±18.43和942.46±18.53。两期病例动脉期和静脉期的WC差异均无统计学意义（P = 0.106，P = 0.143）。ROC分析显示，动脉期IC和nIC的ROC曲线下面积分别为0.829和0.867，nIC的截断值为-0.039用于鉴别T3期和T4a期，相应的敏感度为83.3%，特异度为75.0%；静脉期IC和nIC的ROC曲线下面积分别为0.873和0.905，nIC的截断值为-0.031用于鉴别T3期和T4a期，相应的敏感度为81.0%，特异度为85.0%。
腹部光谱CT扫描有助于鉴别T3期和T4a期胃癌。T4a期胃癌胃周脂肪组织的IC显著高于T3期胃癌。以静脉期nIC的截断值-0.031时可获得更高的诊断效能。
