Objective To compare the differences of the spectral CT parameters between benign and malignant mediastina lymph nodes and to investigate the value of spectral imaging in the differential diagnosis. Methods According to the follow-up and pathology results, a total of 73 patients were enrolled in this study. One experienced radiologist determined the locations of lymph nodes on CT images corresponding to the surgical pathological ones. A total of 47 malignant nodes and 65 benign nodes were found. The longest and shortest diameters of lymph nodes in mediastina window were measured .The vHU, IC, WC, Zef and the CT values of normal lung, normal muscle and lymph nodes at 40, 70 and 140 keV were measured. The indices were compared between the benign nodes and malignant nodes by independent-samples t test. The Spectral HU curves were drawn. Results The long and short diameter of malignant lymph nodes were (28.8 ± 10.5),(20.3 ± 9.1)cm , while they were were (14.0 ± 4.6),(7.5 ± 1.8)cm for benign lymph nodes. Malignant nodes were significantly larger than benign nodes (t= 6.54, 7.13, respectively, P<0.05), The differences of the CT values at 40, 70 and 140 keV and the vHU, IC, WC, Zef for the normal lung, normal muscle and lymph nodes between the two groups had no statistical significance (P>0.05). The two groups showed similar spectral HU curve slopes (1.86 values 1.73). Conclusion Spectral imaging may not be helpful in the differential diagnosis of malignant and benign lymph nodes.

Objective: To investigate the relationship between gut microbiota structure and biochemical changes in patients with different types of nonalcoholic fatty liver disease (NAFLD), in order to provide evidence for clinical diagnosis and prevention of NAFLD. Methods: Forty-eight NAFLD cases (NAFLD group), 40 NAFLD cases with type 2 diabetes mellitus (NAFLD combined with type 2 diabetes mellitus group) and 30 healthy cases (healthy group) were randomly enrolled, and their body mass index, serum alanine aminotransferase, aspartate aminotransferase, total bilirubin, total cholesterol, triglyceride, high density lipoprotein, low density lipoprotein and uric acid were measured. Serum levels of TNF-alpha and fasting insulin were measured using ELISA, and then insulin resistance index was calculated. The gut microbiota of three groups of subjects was detected using 16S rDNA-based high-throughput sequencing. Lastly, the correlations between the various factors were analyzed. The comparison among groups was conducted by 2 test, and one-way ANOVA was used for comparison among groups with normal distribution and homogeneity of variance. Furthermore, the LSD method was used to compare the two groups. K-W rank sum test was used for comparison among groups without normal distribution or homogeneity of variance. Results: Body mass index, aspartate aminotransferase, triglyceride, total cholesterol, low density lipoprotein, uric acid, tumor necrosis factor-alpha, fasting insulin and insulin resistance index of NAFLD group were higher than healthy group, while the high-density lipoprotein was lower in the healthy group, and the difference was statistically significant (P< 0.05). Compared with NAFLD group, the life expectancy, fasting blood glucose and insulin resistance index of NAFLD combined with type 2 diabetes mellitus group were higher, while the body mass index, aspartic acid aminotransferase, total cholesterol and HDL levels were decreased, and the difference was statistically significant (P< 0.05). NAFLD group (P= 0.016) had decreased abundance of firmicutes than healthy group, and the abundancy of the firmicutes in the NAFLD combined with type 2 diabetes group was significantly lower (P< 0.001). The abundance of bacteroidetes in NAFLD combined with type 2 diabetes group was higher than healthy group, and the difference was statistically significant (P= 0.006). At the "genus level," the abundance of Roseburia and Subdoligranulum in the NAFLD group was decreased, while the Roseburia in the NAFLD group with type 2 diabetes group was significantly lower (P< 0.05). In addition, the abundance of Faecalibacterium, Blautia, Anaerostipes and Fusicatenibacter in NAFLD combined with type 2 diabetes group was lower than healthy group, and the difference was statistically significant (P< 0.001). Fusicatenibacter, Blautia, Anaerostipes, Faecalibacterium, and Roseburia were negatively correlated with fasting blood glucose and insulin resistance index levels (r< 0,P< 0.05), and positively correlated with high-density lipoprotein levels (r> 0,P< 0.05). Fusicatenibacter was negatively correlated with tumor necrosis factor-alpha (r= -0.211,P= 0.044), and Lachnoclostridium was positively correlated with body mass index, alanine aminotransferase, aspartate aminotransferase levels (r> 0,P< 0.05). Fusobacterium was positively correlated with aspartate aminotransferase level (r= 0.245,P= 0.019). Escherichia-shigella was positively correlated with fasting blood glucose, low-density lipoprotein, alanine aminotransferase, aspartate aminotransferase levels (r > 0,P< 0.05). Megamonas was negatively correlated with high-density lipoprotein levels (r= -0.231,P= 0.027). Conclusion A structural change of gut microbiota had occurred in patients with NAFLD, suggesting changes in some of these bacterial genuses had relation to insulin resistance and inflammatory response, which may become a new target for the treatment of NAFLD.