Objective: We intend to evaluate the diagnostic efficacy of dual-energy CT radio-mics model based on Iodine Map (IM) in the application of preoperative re-staging of serosal invasion in locally advanced gastric cancer (LAGC) after neoadjuvant chemotherapy (NAC) treatment. Methods: A retrospective study was conducted on 155 patients with LAGC who were treated with standard NAC before operation (including 110 cases in training group and 45 cases in testing group). Two radiologists analyzed all the CT images and carried out the classification. After the semi-automatic drawing of region of interest volume (VOI), we extracted 1226 imaging features from each lesion based respectively on IM and 120kVp images. We adopted Spearman related analysis, Least Absolute Shrinkage and Selection Operator (LASSO) to punish Logistic regression in order to acquire important feature by getting rid of unstable and redundant features. Through multi-factor Logistic regression analysis, we established two prediction models (120kVp and IM-120kVp) based on the features selected respectively by 120kVp and 120kVp combined with IM. Results: Two radio-mics models both showed great prediction accuracy and efficiency in training and testing groups (IM-120kVp: AUC: training group, 0.953, testing group, 0.879; 120kVp: AUC: training group, 0.940, testing group, 0.831). The diagnostic accuracy of both models in the testing group (IM-120kVp: 84.4%, 120kVp: 80.0%) were higher than manual classification (68.9%). The diagnostic efficacy of IM-120kVp model was better than manual classification both in training (P<0.001) and testing groups (P=0.034). Conclusion: The radio-mics model based on dual-energy CT shows convincing diagnostic efficacy in differentiating serosal invasion in preoperative re-staging for LAGC patients after NAC treatment.

The dual-energy X-ray bone densitometer system is the "gold standard" for current X-ray bone density measurement technology, which holds unique advantages such as high measurement accuracy, little time cost and low dosage. In this paper, semiconductor CdZnTe detector module was used to build a bone mineral density energy spectrum measurement platform operated by semiconductor photon. Based on the characteristics of CdZnTe semiconductor detector, we performed the moving least square algorithm on the high-low energy fitting and correction of different materials. The moving least-squares algorithm changes the degree influenced by the surrounding nodes of the target data point through the weight function, which can make the fitting direction of the data point more flexible. The research analyzed the data processing flow of the moving least- squares algorithm performed on the dual-energy X-ray bone density measurement value, and completed the bone density measurement experiment operated by the high-low energy fitting and correction algorithm based on the moving least-squares. According to the experimental results, in this paper we designed and intended to achieve that the dual-energy fitting technology of bone density based on the moving least-squares algorithm can achieve better fitting error accuracy in practical applications, the average fitting error of the detector pixel unit under high-energy conditions is 0.032% while the average fitting error under low-energy conditions is 0.036%. Further data analysis showed that the difference of fitting error between the edge pixels and the center pixels under high and low energy conditions was only 0.012% and 0.011% respectively. This algorithm can effectively improve the bone mineral density measurement accuracy of semiconductor detectors, and reduce the influence of errors caused by the the pixels at the edge of the detector. The photon-counting detectors have an improving effect on the bone density mineral diagnosis influenced by pixel differnce of linear array or plane array photon counting semiconductor detectors.

A set of seismic data broadband processing technology based on adaptive ghost wave suppression is proposed to improve the resolution of data, which is difficult to be solved in natural gas hydrate (NGH) drilling. Firstly, ghost wave suppression technology based on upstream and downstream wave field separation is used to suppress the ghost wave of source and cable. Then the high quality velocity field is obtained by high precision grid tomography inversion velocity modeling technology while the imaging accuracy of hydrate layer is further improved by prestack depth migration imaging. The practice shows that compared with the conventional treatment, the broadband treatment provides clearer seismic characteristics and more detailed information, which is more conducive to the accurate description of the NGH ore body.