Application Of Spectral CT In Evaluating The Differentiation Grade Of Gastric Adenocarcinoma And In Differential Diagnosis Of Gastric Cancer And Gastric Stromal Tumors

Part one Application of Spectral CT in Evaluating the Differentiation grade of Gastric adenocarcinomaObjective:To explore and discuss the application value of gemstone spectral imaging(GSI)in the differentiation of gastric adenocarcinoma.Materials and Methods:87 patients with gastric adenocarcinoma confirmed by pathology were treated with dual-phase enhanced scanning by GSI mode.The spectral curves were obtained with GSI Viewer software,and the slopes of the 40~70,70~140 and 40~140ke V energy ranges were calculated respectively.Iodine concentration(IC)and normalized iodine concentration(NIC)of tumors were also obtained.Patients were divided into 2 groups according to the pathological results,data were analyzed statistically by independent t test.At the same time,the ROC curve was used to evaluate the diagnostic efficiency.Results:Pathological results showed that there were 36 well-moderately differentiated and 51 poorly differentiated adenocarcinomas.(1)The slope of the curve of well-moderately differentiated adenocarcinoma was less than that of poorly differentiated adenocarcinoma.During the artery phase,the slope of the well-moderately differentiated adenocarcinoma and poorly differentiated adenocarcinoma in the40~70,70~140and40~140ke V energy ranges respectively were 2.04±0.41 v.s.2.89±0.74(P=0.001);0.28±0.08 v.s.0.41±0.12(P=0.004)and 0.81±0.17 v.s.1.15±0.30(P=0.001).During the portal vein phase,the slope of the well-moderately differentiated adenocarcinoma and poorly differentiated adenocarcinoma in the 40~70,70~140 and 40~140ke V energy ranges respectively were 3.73±0.65 v.s.5.28±1.23(P<0.001);0.53±0.12 v.s.0.79±0.20(P=0.001)and 1.49±0.28 v.s.2.13±0.51(P<0.001).The biggest AUC(=0.887)of the slope was in the 40~70ke V energy range during the portal vein phase,and taking k=4.60 as threshold value,the sensitivity and specificity was70.6%and 91.7% respectively.(2)The IC of well-moderately differentiated adenocarcinoma were lower than that of poorly differentiated adenocarcinoma,i.e.(9.97±2.22)(100?g/ml)v.s.(14.51±3.89)(100?g/ml)(P=0.001)in artery phase,(18.93±3.63)(100?g/m1)v.s.(27.21±6.55)(100?g/ml)(P<0.001)in portal vein phase respectively.(3)The NIC of well-moderately differentiated adenocarcinoma were lower than that of poorly differentiated adenocarcinoma,i.e.(0.11±0.31)v.s.(0.16±0.41)(P=0.005)in artery phase,(0.44±0.85)v.s.(0.61±0.14)(P=0.001)in portal vein phase respectively.The biggest AUC(=0.889)was NIC during portal vein phase,and taking NIC=0.458 as threshold value,the specificity was 78.3%,sensitivity was 94.1%.Conclusion:The spectral curve,iodine concentration and standard iodine concentration of gastric adenocarcinoma obtained from GSI can reflect the pathological grade of differentiation in a certain extent.We can use quantitative parameters of GSI scanning to assess the grade of differentiated gastric adenocarcinoma.Part two Application of Spectral CT in differential diagnosis of the Gastric adenocarcinoma And the High-risk Gastric Stromal TumorsObjective:To evaluate the application value of gemstone spectral imaging(GSI)in differential diagnosis of the gastric adenocarcinoma and the high-risk gastric stromal tumors(GST).Materials and Methods:Dual-phase enhanced CT scans by GSI mode were analyzed retrospectively on30 gastric adenocarcinoma patients and 24 high-risk GST patients that confirmed by pathology.The spectral curve were obtained with GSI Viewer software,and the slopes of the 40~70,70~140 and 40~140ke V energy ranges were calculated respectively.Iodine concentration(IC),water concentration(WC)and normalized iodine concentration(NIC)of tumors were also obtained.Data were analyzed statistically by independent t test.(1)During the vein phase,the IC(23.78±6.85)(100?g/m1)and NIC(0.54±0.15)of gastric adenocarcinoma were higher than these of the high-risk GST(16.87±2.67)(100?g/m1)and(0.34±0.04)(P<0.05);And there was no significant difference in the WC between the two groups(P>0.05).(2)The slope of the gastric adenocarcinoma in the 40~70,70~140 and40~140ke V energy ranges(4.64±1.28,0.68±0.21 and 1.87±0.53)were higher than these of the high-risk GST(3.35±0.52,0.48±0.11 and 1.34±0.20)(P<0.05).(3)During the artery phase,there were no significant differences in the IC?NIC?WC and the slope in every energy ranges between the two groups(P>0.05).Results:Conclusion:Spectral CT parameters are helpful in differential diagnosis of the gastric cancer and the high-risk GST.In the the vein phase,the IC,NIC and the slope of spectral curve between gastric adenocarcinoma and high-risk GST are different,the differential diagnosis of the two can be achieved using GSI scanning quantitative parameters.