No abstract

Medical CT imaging often encounters metallic implants or some metal interventional therapy apparatus. These metallic objects can produce metal artifacts in reconstruction images, which severely degrade image quality. In this paper, we analyze the difference between polychromatic projection data and Radon transform data and develop an analytical method to reduce metal artifacts. Approximate features of metal artifacts can be obtained by a simplified energy spectrum function of x-ray beam. The developed method can reduce most artifacts, and preserve more original details. It does not require prior knowledge of x-ray energy spectrum and original projection data, avoiding iterative calculation and saving reconstruction time. Simulation experimental results show that the method can greatly remove metal artifacts.

Objective. To study the expression and clinical importance of CD4+T, CD8+T cells, and CD4+T/CD8+T cell percentage in gastric cancer (GC) patients. Methods. The blood count of CD4+T and CD8+T lymphocytes was ascertained via flow cytometry before surgery in 93 GC patients undergoing gastrectomy. The CD4+T, CD8+T, and Foxp3+T lymphocytes in cancerous and normal adjacent tissues and the presence of PD-L1 in cancerous tissues were detected via immunohistochemistry. The link between the permeation of CD4+T, CD8+T lymphocytes in venous blood, and cancer and normal adjacent tissues was analyzed. Results. Lauren histotype, TNM stage, lymphatic/nervous invasion, and NLR level were all considerably associated with peripheral CD4+T and CD8+T cell levels, whereas CD8+T lymphocytes were also associated with vascular invasion ( p < 0.05 ). The CD4+T lymphocyte counts, CD4+T, and CD8+T cell percentage in GC tissues were found to have been decreased when compared to normal adjacent tissues, whereas the CD8+T and Foxp3+T lymphocyte count was higher in GC tissues ( p < 0.05 ). According to a Spearman analysis, the CD4+T and CD8+T cell counts in tumor tissues were positively related to the Foxp3+T lymphocyte count ( p < 0.05 ). Greater peripheral CD4+T lymphocyte counts and increased level of CD4+T/CD8+T percentage corresponded with greater CD4+T cell levels and increased CD4+T/CD8+T quantity in normal adjacent tissues. Higher levels of peripheral CD8+T cells corresponded with higher quantities of CD8+T cells in cancer tissues. A reduced CD4+T lymphocyte count, together with a reduced CD4+T/CD8+T percentage in venous blood, was consistent with a diminished CD4+T cell count along with a reduced CD4+T/CD8+T lymphocyte ratio in cancer and normal adjacent tissues. Conclusion. The peripheral quantity of CD4+T and CD8+T lymphocytes in GC patients can partly reflect the infiltrating state of these lymphocytes in cancer and normal adjacent tissues and can preliminarily predict immunotherapy response to a certain extent.

To explore the performance of improved watershed algorithm in processing magnetic resonance imaging (MRI) images and the effect of the processed images on the treatment of lumbar brucellar spondylitis (BS) with abscess by the posterior approach, the watershed algorithm was improved by adding constraints such as noise reduction and regional area attribute. 50 patients with abscessed lumbar disc herniation admitted to the hospital from January 2018 to January 2019 were selected, and all of them were examined by MRI. They were rolled into two groups in random. The treatment group (n = 25) accepted surgery with the aid of MRI images processed by the improved watershed algorithm, and the control group (Ctrl group) (n = 25) accepted surgery with the aid of unprocessed MRI images. The improved watershed algorithm can accurately segment the spine, and the segmentation results were relatively excellent. In contrast with the unprocessed MRI image, that processed by the improved watershed algorithm had a positive effect on the operation. In contrast with the Ctrl group, the visual analogue scale pain score (VAS), oxygen desaturation index (ODI), erythrocyte sedimentation rate (ESR), and high sensitivity C-reactive protein (CRP) were obviously lower ( p < 0.05 ). The improved watershed algorithm proposed performs better in MRI image processing and can effectively enhance the resolution of MRI images. At the same time, the posterior approach has a good effect in the treatment of lumbar BS with abscess and is worthy of clinical promotion.

ERCC1 codon 118 C/T polymorphism was not associated with ERCC1 mRNA and protein expression, FOLFOX-4 response, and progression-free survival (PFS) or overall survival (OS). High ERCC1 mRNA and protein expression levels were associated with significantly lower FOLFOX-4 responses, PFS, and OS. ERCC1 codon 118 C/T polymorphism is not an important prognostic marker for advanced gastric cancer. Determination of ERCC1 mRNA and protein levels may be beneficial in predicting the response and outcome of FOLFOX-4 therapy in gastric cancer.