The COVID-19 epidemic has spread to the whole world for three years and has had a serious impact on human life, health and economic activities. China's epidemic prevention and control has gone through the following stages: emergency unconventional stage, emergency normalization stage, and the transitional stage from the emergency normalization to the "Category B infectious disease treated as Category B" normalization, and achieved a major and decisive victory. The designated hospitals for prevention and control of COVID-19 epidemic in Tianjin has successfully completed its tasks in all stages of epidemic prevention and control, and has accumulated valuable experience. This article summarizes the experience of constructing a hospital infection prevention and control system during the "Category B infectious disease treated as Category A" period in designated hospital. The experience is summarized as the "Cluster" hospital infection prevention and control system, namely "three rings" outside, middle and inside, "three districts" of green, orange and red, "three things" before, during and after the event, "two-day pre-purification" and "two-director system", and "one zone" management. In emergency situations, we adopt a simplified version of the cluster hospital infection prevention and control system. In emergency situations, a simplified version of the "Cluster" hospital infection prevention and control system can be adopted. This system has the following characteristics: firstly, the system emphasizes the characteristics of "cluster" and the overall management of key measures to avoid any shortcomings. The second, it emphasizes the transformation of infection control concepts to maximize the safety of medical services through infection control. The third, it emphasizes the optimization of the process. The prevention and control measures should be comprehensive and focused, while also preventing excessive use. The measures emphasize the use of the least resources to achieve the best infection control effect. The fourth, it emphasizes the quality control work of infection control, pays attention to the importance of the process, and advocates the concept of "system slimming, process fattening". Fifthly, it emphasizes that the future development depends on artificial intelligence, in order to improve the quality and efficiency of prevention and control to the greatest extent. Sixth, hospitals need to strengthen continuous training and retraining. We utilize diverse training methods, including artificial intelligence, to ensure that infection control policies and procedures are simple. We have established an evaluation and feedback mechanism to ensure that medical personnel are in an emergency state at all times.

Objective:To investigate the value of quantitative parameters of amide proton transfer-weighted (APTw) imaging and dynamic contrast-enhanced (DCE)-MRI for preoperative assessment of human epidermal growth factor receptor 2 (Her-2) gene expression in endometrial cancer (EC).Methods:This research conducted a diagnostic pilot study involving 68 patients with pathologically confirmed EC at the First Hospital of Dalian Medical University from August 2019 to August 2023. Patients were categorized into Her-2-positive group (33 cases) and Her-2-negative group (35 cases) based on postoperative Her-2 gene expression results. Utilizing the APTw and DCE-MRI sequences, quantitative parameters including the asymmetric magnetization transfer ratio (MTR asym) for APTw and the volumetric transfer constant (K trans), plasma volume fraction (V p), extracellular mesenchymal space (V e), and rate constant (K ep) for DCE-MRI were acquired for the lesion site. Statistical differences in the values of each quantitative parameter between the two groups were evaluated using two independent sample t test or Mann-Whitney U test. The study incorporated quantitative parameters and clinicopathological data of patients to identify independent predictors of EC Her-2 gene expression through logistic regression analysis. A diagnostic model was developed using binary logistic regression analysis. The effectiveness of the parameters and diagnostic model was evaluated using receiver operating characteristic curves. DeLong test was used to compare the differences between the areas under the curves (AUC). Results:The study found statistically significant differences in MTR asym, K trans, and V e between the Her-2-positive group and the Her-2-negative group ( Z=2.55, P=0.011; t=-2.03, P=0.047; t=-2.13, P=0.037). However, the differences in V p and K ep were not statistically significant ( Z=0.58, P=0.560; Z=0.19, P=0.849). MTR asym emerged as a significant independent predictor of Her-2 gene expression in EC ( OR=1.016, 95% CI 1.003-1.030, P=0.014). Incorporating MTR asym, K trans, and V e, the diagnostic model yielded an AUC (95% CI) of 0.745 (0.625-0.864). The AUC (95% CI) for MTR asym, K trans, and V e alone were 0.680 (0.551-0.808), 0.623 (0.485-0.760), and 0.656 (0.523-0.789) respectively. The differences in AUC between the diagnostic model and individual predictors MTR asym, K trans, and V e were not found to be statistically significant ( Z=1.40, 1.92, 1.37, P=0.163, 0.055, 0.171). Conclusion:The quantitative parameters of APTw and DCE-MRI sequences can preoperatively assess EC Her-2 gene expression from a different perspective, with MTR asym potentially serving as a valuable independent predictor.

Objective To summarize the clinical characteristics of autoimmune pancreatitis (AIP) and discuss the role and significance of surgical intervention in the treatment of AIP.Methods The clinical data of 11 patients with preoperative confirmed AIP and 8 patients with preoperative suspected AIP receiving surgical intervention at the First Affiliated Hospital of Harbin Medical University from 2011 to 2017 were retrospectively analyzed.Results Among 11 preoperatively confirmed AIP patients,9 (47.4％) underwent endoscopic retrograde cholangiopancreatography (ERCP) with nasal bile duct implantation or biliary stent drainage,and 2 (10.5％)underwent choledochojejunostomy.Among 8 putative AIP patients in which a cancer was suspected 4 (21.1％) underwent choledochojejunostomy,3 (15.8％) did pancreaticoduodenectomy,and 1 (5.3％) had distal pancreatectomy plus splenectomy.Postoperative pathology confirmed pancreatic cancer in 3 cases,IPMN in 1 case.Conclusions While autoimmune pancreatitis is IgG4 related disease,surgical intervention is indicated when there is poor response to drug treatment or when a cancer is to be ruled out.

Objective: To investigate the value of the multiple model parameters of intravoxel incoherent motion (IVIM) in identification of stage endometrial carcinoma (EC) and endometrial polyp (EP). Methods: The clinical and imaging data of 31 patients with stage EC (group EC) and 14 patients with EP (group EP), confirmed by postoperative pathological examination, were retrospectively analyzed, all patients were performed on 1.5T MR (including IVIM sequence, b=0, 20, 50, 100, 150, 200, 400, 800, 1 200, 2 000, 3 000 s/mm2) before operation. The IVIM multi-model parameter values of the lesions were measured and compared between the two groups, including the standard apparent diffusion coefficient (ADC-stand), slow-apparent diffusion coefficient (ADC-slow), fast-apparent diffusion coefficient (ADC-fast), perfusion fraction (f), distributed diffusion coefficient (DDC) and water molecular diffusion heterogeneity index (α). The ROC curve was used to evaluate the differential diagnostic efficacy of IVIM parameters for stage EC and EP. Results: The ADC-stand value, ADC-slow value, f-value, DDC value and α value of the EC group were all less than the EP group, and the ADC-fast value was greater than the EP group (all P=0.001). ROC curve results showed the standard ADC value, ADC-slow value, ADC-fast value, f value, DDC value and α value had differential diagnostic value for stage EC and EP, the AUC was 0.885, 0.877, 0.919, 0.926, 0.906 and 0.902, respectively (all P<0.05). Conclusion: The multi-model parameters of IVIM sequence can effectively identify stage EC and EP.

Purpose To explore the feasibility of denoising algorithm-PixelShine algorithm based on deep learning to enhance the quality of abdominal arterial phase CT images rebuilt by 70 kVp combined with adaptive statistical iterative reconstruction-Veo (ASiR-V). Materials and Methods Abdominal arterial phase images of 33 patients [body mass index (BMI) BMI≤20 kg/m2] scanned by GE Revolution CT were retrospectively analyzed (group A) using 70 kVp tube voltage and 50% ASiR-V technique. PixelShine algorithm B2 mode was applied to post-process group A images to obtain PixelShine image (group B). Two observers rated the image quality of the two groups via a 5-point rating system. The consistency of the rating was analyzed. The difference in ratings, noise, virtual signal-to-noise ratio (SNR) of liver and pancreas and contrast noise ratio (CNR) were compared between the two groups of images. Results The image quality rating of group A and B were(3.12±0.33) scores and(3.97±0.53) scores respectively,noise value(14.50±1.42)HU vs(10.05±1.80)HU, liver virtual SNR 4.51±0.53 vs 6.78.±1.27,liver virtual CNR 0.89±0.55 vs 1.42±0.81,pancreatic virtual SNR 9.51±1.69 vs 13.87±3.26, and pancreatic virtual CNR 5.83±1.66 vs 8.48±2.46.The quality rating of images,liver and pancreas virtual SNR,CNR in group B were all higher than those in group A, and the image noise of group B decreased about 31% compared with that of group A, the difference was statistically significant (P<0.05). Conclusion Post-processing with PixelShine algorithm can improve the image quality of 70 kVp abdominal arterial phase, significantly reduce image noise, and increase image SNR and CNR.

Objective To investigate the value of diffusion kurtosis imaging (DKI)quantitative parameters in evaluating patholog-ical grade of cervical squamous cell carcinoma (CSCC).Methods The DKI images of 45 patients with CSCC were analyzed retrospec-tively.According to the results of pathology,22 cases were divided into poorly differentiated group and 23 cases well-moderately dif-ferentiated group.The DKI parameters of two groups were measured by two observers,which included mean kurtosis (MK),axial kurtosis (Ka),radial kurtosis (Kr),fractional anisotropy of kurtosis (FAk),mean diffusivity (MD),axial diffusivity (Da),radial diffusivity (Dr)and fractional anisotropy (FA).The intra-class correlation coefficients (ICC)was used to test the consistency of the parameters measured results on two observers.The two independent samples t test was used to compare the parameters of two groups,and the ROC curve was used to evaluate the effectiveness of each parameter in order to evaluate the poorly differentiated CSCC and find the boundary values.Results The data consistency of two observers were good (ICC>0.75).The MK,Ka and Kr values on poorly differentiated CSCC were greater than that on well-moderately differentiated (P<0.05),the MD,Da and Dr values were less than that on well-moderately differentiated (P<0.05),the FAk and FA values had no difference (P>0.05).Thearea un-der curve (AUC)of MK,Ka,Kr,MD,Da and Dr values to diagnose poorly differentiated CSCC were 0.914,0.831,0.865,0.850, 0.778 and 0.865,respectively.The boundary values of diagnosing poorly differentiated CSCC were MK≥0.973,Ka≥1.075,Kr≥0.823, MD≤0.974μm2/ms,Da≤1.185μm2/ms and Dr≤0.762μm2/ms,respectively.Conclusion DKI can effectively predict the patho-logical grading of CSCC,which has a good clinical application prospects.

Purpose To explore the influence of duration of scan acquisition on perfusion parameters in whole renal perfusion with Revolution CT.Materials and Methods Fortytwo patients without pathologic changes in bilateral kidneys were divided into group A (with short perfusion time) and group B (with long perfusion time) according to the duration time of the perfusion scan.The Revolution CT axial scan mode was used for perfusion scan,and the width of detector was 16 cm.The perfusion CT series were performed in 50 seconds,each comprising 25 volumes with identical parameters (80 kVp,200 mA) in group A.The perfusion CT series were performed in 594 seconds,each comprising 23 volumes with identical parameters (120 kVp,55 mA) in group B.The source datasets were post-processed with CT Perfusion 4D software,and the perfusion parameter maps were obtained when right renal abdominal aorta was taken as entry artery.Perfusion parameters of bilateral kidneys were compared within and between group A and group B,respectively.CT dosage index of volume (CTDIvol) and dose length product (DLP) were recorded.The effective dose (ED) was calculated and compared.Results There were no statistical difference in all parameters between bilateral kidneys within each group (P＞0.05).However,blood volume,time to peak,and permeability surface in the cortex and medulla of bilateral kidneys all showed differences between the above two groups (P＜0.05).The mean transit time in the medulla between the two groups was different (P＜0.05),but neither the blood flow in the medulla and cortex nor the mean transit time of the cortex had difference between the two groups (P＞0.05).The effective radiation doses were (23.10± 4.39)mSv in group A and (23.19±0.00) mSv in group B,respectively (without statistic difference:P＞0.05).Conclusion CT perfusion parameters with different duration time show differences in whole renal perfusion;therefore,scanning time needs to be set according to the clinical application.

Objective To assess the value of spectral CT imaging in distinguishing mass type colorectal adenocarcinoma from colorectal adenoma. Methods Forty patients underwent preoperative abdominal dual energy spectral CT scan were analyzed restrospectively, including 17 with colorectal adenomas and 23 with mass type colorectal adenocarcinomas proven by endoscopic and surgical pathology. All patients underwent plain and three-phase enhanced CT scanning. The conventional polychromatic CT value and its pre- and postcontrast CT values, monochromatic CT value of 40 to 100 keV, the slope of spectral curve and iodine(water) concentration were measured, and the maximum diameter of the lesion was recorded. The maximum diameters of the lesions and imaging parameter differences between the adenomas and adenocarcinomas in plain and three-phase enhanced scan were analyzed with independent sample t tests. The data of the parameters with significant differences were further analyzed by ROC curves. Results The maximum diameters of the adenomas and mass type adenocarcinomas were (1.97 ± 0.54), (2.32±0.53) cm respectively, and there was no statistically significant difference (t=-2.011, P=0.051). There was no statistically differences of the conventional polychromatic CT value and its pre-and postcontrast CT values between the two groups in 4 phases (P>0.05). However, in the arterial phase, the CT values of adenomas were significantly lower than those of adenocarcinomas at low (40, 50 keV) energy (P<0.05). The values did not differ significantly between these two groups at other phases (P>0.05). The slope of spectral curve and the iodine(water) concentration both showed significant differences in the arterial phase between the two groups (P<0.05), while they were not significantly different at other phases (P>0.05).The largest area under the ROC curve of the iodine(water) concentration in the arterial phase was 0.757 in differentiating adenomas and mass type adenocarcinomas, with sensitivity of 73.9%and specificity of 82.4%at the cut-off of 21.02 mg/cm3. Conclusion Spectral CT imaging is valuable in differentiating colorectal adenoma from mass type colorectal adenocarcinoma with the parameters of the arterial phase.

Objective To evaluate the feasibility of multi-parameter MRI in diagnosing ovarian endometrial cysts. Methods Pelvic MRI of 68 patients with confirmed pathological diagnosis were retrospectively reviewed. The patients were divided into ovarian endometriosis (35 patients with 42 lesions, group A) and other cystic lesions (33 patients with 38 lesions , group B).The signal intensity value of T1WI, T2WI of cyst fluid and iliopsoas, ADC value, phase values and R2*values were obtained, cyst fluid/iliopsoas ratios (T1R and T2R) were calculated. The non-parametric Mann-Whitney U test was employed to compare parameter values between the two groups. The values of diagnostic performance were analyzed by using receiver operating characteristic curve (ROC). Use the Logistics regression parameters of diagnostic efficacy to select the highest Youden index for the best parameter association after combining the parameters step by step. Results The median of T1R, T2R, ADC, phase, T1R and R2*values for group A were 3.39, 5.28, 1.20×10-3 mm2/s,2.19×10-2, 15.08 Hz respectively, and that of group B were 0.91, 10.85, 2.64×10-3mm2/s,2.67×10-2, 3.01 Hz, respectively. There were statistically significant difference between the two groups (P<0.01).The AUC of T1R, T2R, ADC value, phase values and R*2 value were 0.930, 0.874, 0.891, 0.685 and 0.924 respectively, and there was no difference among them (P>0.05). When combining T1R, ADC value, R2*value together, the Youden index (0.849 7) was highest. Conclusion Combining T1R, ADC and R2* values can provide an effective way to discriminate endometrial ovarian cyst from other ovary cystic lesions.

Objective To explore the source of endothelial cells in tumor vessels by A 549 tumor model with GFP nude mouse.Methods To establish the A 549 lung cancer models with GFP nude mice, expression of CD 31 was determined by immunofluorescence to label tumor vessels; to observe and take a picture of the tumor frozen section by confocal microscopy and invert microscope;expression of GFP in tumor vessels was determined by immunohistochemistry. Result The results of immunofluorescence showed:Tumor interstitial vascular endothelial cells or endothelial cells clusters and micro-vascular lumen size and shape are clearly visible by immunofluorescence, and part of vessels with no obvious lumen or irregular lumen.We can see green fluorescent in tumor cells of tumor tissue and endothelial cells which form of tumor vessels.The results of immunohistochemistry showed: expression of GFP was determined in cytoplasm of tumor stromal cells and endothelial cells in tumor vessels.Conclusion The endothelial cells which formed tumor neovessels that derived from GFP nude mice partly and the other part derived from tumor cells.