ABSTRACT
Objective To evaluate spectral CT imaging in characterizing the pathological type and the differentiation of gastric cancer.Methods Ninety-one patients diagnosed of gastric cancer were retrospectively analyzed.Patients were all underwent triple-phase enhanced scan using single source dualenergy CT on gemstone spectral imaging(GSI) mode.Three types of images were reconstructed for analysis:the water concentration (WC),iodine concentration (IC),and normalized iodine concentration (NIC).The patients were divided into groups of mucinous carcinoma (MUC),including mucinous adenocarcinoma and signet ring cell carcinoma,and non-mucinous gastric carcinoma (non-MUC).Independent-samples t test was used for statistical analysis.Results There were 24 patients of MUC and 67 patients of non-MUC.The IC and NIC of the non-MUC were significantly higher than the MUC in vein phase (VP) and in parenchymal phase (PP) [(21.33 ±6.31) × 100 vs (16.94 ±6.13) × 100 μg/ml,0.55 ±0.17 vs 0.42 ±0.14 in VP,and(20.65 ±5.49) × 100 vs (18.07 ±4.51) × 100 μg/ml,0.72 ±0.20 vs 0.57 ±0.12 in PP,respectively t =-2.948,-3.362,-2.261,-4.326,P ＜0.05].The IC and NIC of the signet ring cell carcinoma were statistically higher than those of the mucinous adenocarcinoma [(19.36 ± 4.75) × 100 vs (12.10 ±5.92) ×100μg/ml,0.49 ± 0.09 vs0.28±0.11 in VP,and (19.88±3.28) ×100 vs (14.45±4.62) ×100 μg/ml,0.63 ±0.08 vs 0.47 ±0.11 in PP,respectively t =3.253,5.180,3.339,3.850,P ＜0.01].For the poorly differentiated and well /moderately differentiated adenocarcinoma,the IC and NIC of the former were higher than those of the latter in VP and PP [(23.48 ±6.49) × 100 vs (18.98 ±5.26) × 100 μg/ml,0.61±0.16vs0.48±0.15 in VP,and (22.95±5.51) ×100 vs (18.28±4.47) ×100 μg/ml,0.81 ± 0.21 vs 0.63 ± 0.15 in PP,respectively t =3.098,3.249,3.766,4.117,P ＜ 0.01].The between-group differences of WC,IC and NIC in artery phase were no significant (P ＞ 0.05).Conclusions Different pathological types could determine different IC.The spectral CT imaging may be helpful for characterizing the pathological type of gastric cancer.