Application Of Dual-energy CT In Preoperative Staging Of Ovarian Serous Carcinoma

Objective:Discussing the value of dual-energy CT(DECT)in preoperative staging of ovarian serous carcinoma.Methods: Collecting 31 patients with gynecological inpatients from Guizhou Provincial People's Hospital from October 2017 to February 2019.After surgery,all the pathological diagnosis were ovarian serous carcinoma.10 days before operation,abdominal conventional plain scan and DECT enhanced dual-phase were used with Siemens Somatom Force CT scanner.Two high-grade doctors use double blind method to read the films,observe the location,size,plain CT value,CT value of arteriovenous period,normalized iodine concentration(NIC)and slope of energy spectrum curve in arteriovenous period;observe and record the location of primary ovarian tumor,tumor breakthrough capsule,pelvic infiltration,peritoneal implantation,lymph node metastasis,distant metastasis,etc.Track the operation process,and record the pelvic and abdominal cavity conditions as well as the surgical procedure.After the lymph nodes which were taken during the operation are marked,use DECT to scan them again.If the shape,size and location of the lymph nodes are different from the preoperative images,it is considered as cannot match.Then,the observation results of the DECT scan image were compared with the preoperative pathological results.Using SPSS20.0 statistical software to statistical analysis this study data.Analyse the lymph node.Draw a receiver operating characteristic curve(ROC)with statistically significant quantitative parameters,calculate the specificity and sensitivity of the threshold when the maximum value of the Youden index is the diagnostic threshold.According to the DECT scan image determine the preoperative staging of ovarian serous carcinoma,separately calculate the accuracy,specificity and sensitivity of DECT in the diagnosis of primary lesions,tumor surface's breaches,pelvic infiltration,peritoneal implantation,lymph node and distant metastasis.Finally,Kappa test was used to compare the consistency of DECT preoperative analysis and surgical pathological analysis.The test level is P<0.05.Results:Among the 31 patients with ovarian serous carcinoma,17 were diagnosed with lymph node metastasis and 14 with no lymph node metastasis.A total of 46 metastatic lymph nodes and 355 non-metastatic lymph nodes were included in the study.The difference between metastatic lymph node and non-metastatic lymph node in short diameter,short aspect ratio,arteriovenous CT value,arteriovenous NIC,and arteriovenous energy spectrum curve were statistically significant(P<0.05),among them,venous NIC has the highest diagnostic accuracy(area under curve=0.872),when NIC=0.51,the specificity of diagnosis of metastatic lymph nodes of ovarian serous carcinoma was 84.50%,and the sensitivity was 87.00%.In the staging of ovarian serous carcinoma,the surgical pathological stage was 6 cases in stage I,3 cases in stage II,20 cases in stage III,and 2 cases in stage IV;the DECT preoperative stage was 6 cases of stage I,4 cases of stage II,19 cases of stage III,and 2 cases of stage IV.The overall accuracy of DECT in preoperative staging of ovarian serous carcinoma was 83.87%.The accuracy of DECT in the diagnosis of single and bilateral lesions,tumor surface's breaches,pelvic infiltration,peritoneal implantation,lymph node and distant metastasis was 83.87%-100%,specificity was 80.00%-100%,and sensitivity was 70.00%-100%.The Kappa index of DECT staging and surgical pathological staging was 0.772,P<0.05,suggesting a high diagnostic consistency and was statistically significant.Conclusion: Dual-energy CT has high application value in preoperative staging of ovarian serous carcinoma and is beneficial to the qualitative evaluation of preoperative lymph nodes.It provides accurate imaging evidence for clinicians to clarify the treatment plan and to draw up the methods and scope of operation.