To analyze the CT features of solid pseudopapillary tumor of pancreas (SPTP), and correlation with the pathological findings of the disease so as to improve the diagnostic abilities, the CT images and the clinical manifestations, we retrospectively analyzed the pathological materials of 23 cases with surgery and pathology proved SPTP. In the 23 patients, 21 cases were female (91.3%) and 2 were male (8.7%). The most common symptom was abdominal discomfort with dull pain in 12 patients (52.2%). Others included the pancreatic mass that was detected incidentally during physical examination in 9 patients (39.1%), nausea/vomiting in 2 patients (8.7%). And 1 case of female patients had 2 lesions. In the 24 tumors, 6 cases were located at the head (25.0%), 3 were at neck (12.5%), 8 cases were at body (33.3%), and 7 cases were at tail of pancreas respectively (29.2%). The long-axis diameter ranged from 2.1cm to 20.1cm (mean 6.4cm). 9 tumors were mostly solid component (37.5%), 10 tumors were contained similar proportion of solid and cystic part (41.7%), and mainly cystic components in 5 tumors (20.8%). In 9 of the 23 patients, calcification was found in the tumor (39.1%). In 2 of the 23 patients, bleeding was seen in the mass (8.7%). The dilation of intrahepatic bile duct was found in 1 patient (8.7%). Liver metastasis was showed in one patient (8.7%). On post-contrast CT scan, solid parts demonstrated mild enhancement at the arterial phase. At the portal phase, solid parts were enhanced continuously in all cases, and the enhancement degrees were lower than normal pancreatic tissue. The cystic parts of all lesions showed no enhancement. Pseudo papillary structure, hemorrhage, necrosis, or cystic degeneration were found in all patients by histological study. In a word, SPTP has comparatively characteristic CT imaging features consistent with histological features, when combined with clinical manifestations, could be correctly diagnosed and differentially diagnosed.
ObjectiveTo investigate the radiomics features to distinguish invasive lung adenocarcinoma with micropapillary or solid structure. MethodsA retrospective analysis was conducted on patients who received surgeries and pathologically confirmed invasive lung adenocarcinoma in our hospital from April 2016 to August 2019. The dataset was randomly divided into a training set [including a micropapillary/solid structure positive group (positive group) and a micropapillary/solid structure negative group (negative group)] and a testing set (including a positive group and a negative group) with a ratio of 7∶3. Two radiologists drew regions of interest on preoperative high-resolution CT images to extract radiomics features. Before analysis, the intraclass correlation coefficient was used to determine the stable features, and the training set data were balanced using synthetic minority oversampling technique. After mean normalization processing, further radiomics features selection was conducted using the least absolute shrinkage and selection operator algorithm, and a 5-fold cross validation was performed. Receiver operating characteristic (ROC) curves were depicted on the training and testing sets to evaluate the diagnostic performance of the radiomics model. ResultsA total of 340 patients were enrolled, including 178 males and 162 females with an average age of 60.31±6.69 years. There were 238 patients in the training set, including 120 patients in the positive group and 118 patients in the negative group. There were 102 patients in the testing set, including 52 patients in the positive group and 50 patients in the negative group. The radiomics model contained 107 features, with the final 2 features selected for the radiomics model, that is, Original_ glszm_ SizeZoneNonUniformityNormalized and Original_ shape_ SurfaceVolumeRatio. The areas under the ROC curve of the training and the testing sets of the radiomics model were 0.863 (95%CI 0.815-0.912) and 0.857 (95%CI 0.783-0.932), respectively. The sensitivity was 91.7% and 73.7%, the specificity was 78.8% and 84.0%, and the accuracy was 85.3% and 78.4%, respectively. ConclusionThere are differences in radiomics features between invasive pulmonary adenocarcinoma with or without micropapillary and solid structures, and the radiomics model is demonstrated to be with good diagnostic value.
Fluid shear stress (FSS) caused by interstitial fluid flow within trabecular bone cavities under mechanical loading is the key factor of stimulating biological response of bone cells. Therefore, to investigate the FSS distribution within cancellous bone is important for understanding the transduction process of mechanical forces within alveolar bone and the regulatory mechanism at cell level during tooth development and orthodontics. In the present study, the orthodontic tooth movement experiment on rats was first performed. Finite element model of tooth-periodontal ligament-alveolar bone based on micro computed tomography (micro-CT) images was established and the strain field in alveolar bone was analyzed. An ideal model was constructed mimicking the porous structure of actual rat alveolar bone. Fluid flow in bone was predicted by using fluid-solid coupling numerical simulation. Dynamic occlusal loading with orthodontic tension loading or compression loading was applied on the ideal model. The results showed that FSS on the surface of the trabeculae along occlusal direction was higher than that along perpendicular to occlusal direction, and orthodontic force has little effect on FSS within alveolar bone. This study suggests that the orientation of occlusal loading can be changed clinically by adjusting the shape of occlusal surface, then FSS with different level could be produced on trabecular surface, which further activates the biological response of bone cells and finally regulates the remodeling of alveolar bone.
The Monte Carlo N-Particle (MCNP) is often used to calculate the radiation dose during computed tomography (CT) scans. However, the physical calculation process of the model is complicated, the input file structure of the program is complex, and the three-dimensional (3D) display of the geometric model is not supported, so that the researchers cannot establish an accurate CT radiation system model, which affects the accuracy of the dose calculation results. Aiming at these two problems, this study designed a software that visualized CT modeling and automatically generated input files. In terms of model calculation, the theoretical basis was based on the integration of CT modeling improvement schemes of major researchers. For 3D model visualization, LabVIEW was used as the new development platform, constructive solid geometry (CSG) was used as the algorithm principle, and the introduction of editing of MCNP input files was used to visualize CT geometry modeling. Compared with a CT model established by a recent study, the root mean square error between the results simulated by this visual CT modeling software and the actual measurement was smaller. In conclusion, the proposed CT visualization modeling software can not only help researchers to obtain an accurate CT radiation system model, but also provide a new research idea for the geometric modeling visualization method of MCNP.
Objective To access the diagnostic performance of CT texture analysis to differentiate atypical pancreatic solid pseudopapillary tumor (SPT) from pancreatic ductal adenocarcinoma (PDAC). Methods CT images of 26 patients with pathologically proved atypical SPT and 52 patients with PDAC were analyzed. 3D regions of interest (ROIs) on arterial phase (AP) and portal venous phase (PVP) images were drawn by ITK-Snap software. A.K. software (GE company, USA) was used to extract texture features for the discrimination of atypical SPT and PDAC. After removing redundancy (by a correlation analysis through R software), texture features were selected by single-factor and multi-factor logistic regression, and logistic regression model was finally established. Receiver operating characteristic (ROC) analysis was performed to assess the diagnostic performance of single texture feature and logistic model. Results A total of 792 texture features ［396 of AP, 396 of PVP］ from AP and PVP CT images were obtained by A.K. software. Of these, 61 texture features (35 of AP, 26 of PVP) were selected by R software (result of correlation analysis showed that correlation coefficient >0.7). Two texture features, including MinIntensity and Correlation_AllDirection_offset1_SD, were selected to establish logistic model. The sensitivity and specificity of these 2 texture features were 71.15% and 76.92%, 63.46% and 76.92% respectively, the area under curve ( AUC) were 0.740 and 0.754 respectively. The model’s sensitivity and specificity were 73.08% and 80.77% respectively, the AUC value was 0.796. There was no significance among the model, MinIntensity, and Correlation_AllDirection_offset1_SD (P>0.05). Conclusions CT texture analysis of 3D ROI is a quantitative method for differential diagnosis of atypical SPT from PDAC.
Objective To investigate the effect of solid lipid nanoparticles (SLNs) on enhancing the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) in vitro by resveratrol (Res), and provide a method for the treatment of bone homeostasis disorders. MethodsRes-SLNs were prepared by high-temperature emulsification and low-temperature solidification method, and then the 2nd-3rd generation BMSCs from Sprague Dawley rat were co-cultured with different concentrations (0, 0.1, 1, 5, 10, 20 μmol/L) of Res and Res-SLNs. The effects of Res and Res-SLNs on the cell viability of BMSCs were detected by cell counting kit 8 (CCK-8) and live/dead cell staining; the effects of Res and Res-SLNs on the osteogenic differentiation of BMSCs were detected by alkaline phosphatase (ALP) staining and alizarin red S (ARS) staining after osteogenic differentiation induction, and the optimal concentration of Res-SLNs for gene detection was determined. Anti-osteocalcin (OCN) immunofluorescence staining and real-time fluorescent quantitative PCR (RT-qPCR) were used to detect the effect of Res and Res-SLNs on osteoblast-related genes (ALP and OCN) of BMSCs. ResultsLive/dead cell staining showed that there was no significant difference in the number of dead cells between Res and Res-SLNs groups; CCK-8 detection showed that the activity of BMSCs in Res group was significantly reduced at the concentration of 20 μmol/L (P<0.05), while Res-SLNs activity was not affected by Res concentration (P>0.05). After osteogenic differentiation, the staining intensity of ALP and ARS in both groups was dose-dependent. The percentage of ALP positive staining area and the percentage of mineralized nodule area in Res group and Res-SLNs group reached the maximum at the concentrations of 10 μmol/L and 1 μmol/L, respectively (P<0.05), and then decreased gradually; the most effective concentration of Res-SLNs was 1 μmol/L. The expression of OCN and the relative expression of ALP and OCN mRNA in Res-SLNs group were significantly higher than those in Res group (P<0.05). ConclusionEncapsulation of SLNs can improve the effect of Res on promoting osteogenesis, and achieve the best effect of osteogenic differentiation of BMSCs at a lower concentration, which is expected to be used in the treatment of bone homeostasis imbalance diseases.
Stage ⅠA lung adenocarcinoma presented as ground glass dominant on thin-section high-resolution CT scan is a special subtype of lung cancer. The characteristics of this subtype are quite different from the other patients, which presented as lower malignancy and better prognosis. Clinical, pathological and imaging studies have revealed that the proportion of the solid component in part-solid ground glass nodule is closely related with the pathological type and the prognosis of lung cancer. The methods for the assessment of the solid components in the ground glass nodule can be classified into three types, including subjective assessment, two dimensional measurement and three dimensional measurement. This review summarized the advantages and the limitations of these three methods. We also reviewed the clinical application of these techniques.
ObjectiveTo review the research progress on intra-articular screw penetration in proximal humeral fracture treated with locking plate. MethodsThe domestic and foreign literature about the proximal humeral fracture treated with locking plate was extensively reviewed. The incidence of screw penetration and risk factors were summarized from both primary and secondary screw penetrations, and the reasons of the intra-articular screw penetration and the technical solutions to avoid the penetration were analyzed. ResultsThe incidence of intra-articular screw penetration is about 11%-30%, which includes primary and secondary screw penetrations. The primary screw penetration is related to improper operation, inaccurate measurement, and “Steinmetz solid” effect, which results in inadequate fluoroscopy and blind zone. The secondary screw penetration is related to the loss of reduction and varus, collapse, and necrosis of the humeral head. The risk factors for intra-articular screw penetration include the bone mass density, the fracture type, the quality of fracture reduction, the applied location, number, and length of the plate and screws, and whether medial column buttress is restored. Improved fracture reduction, understanding the geometric distribution of screws, good intraoperative fluoroscopy, and reconstruction of medial column buttress stability are the key points for success. ConclusionThe risk of the intra-articular screw penetration in the proximal humeral fractures treated with locking plates is still high. Follow-up studies need to further clarify the cause and mechanism of screw penetration, and the risk factors that lead to screw penetration, in order to effectively prevent the occurrence of this complication.
ObjectiveTo investigate the radiological and clinicopathological factors affecting the postoperative recurrence of early lung adenocarcinoma with micropapillary/solid structure.MethodsA total of 198 patients undergoing surgical resection for early stage lung adenocarcinoma in the First Affiliated Hospital of Nanjing Medical University from January 2016 to August 2019 were enrolled, including 100 males and 98 females, aged 28-82 (53.5±9.5) years. All patients were allocated to a recurrence group (n=21) and a non-recurrence group (n=177) according to postoperative recurrence status. Correlations of imaging and clinical features and clinical outcomes were analyzed to determine prognostic significance.ResultsThe mean follow-up time was 27.0±11.2 months. There was no statistical difference in the imaging features of tumor maximum diameter in mediastinal window (P=0.014), C/T ratio (P=0.001), bronchial positive sign (P=0.015), pathological features of vascular invasion (P=0.024) and postoperative chemotherapy (P<0.001) between the two groups. In multivariate analysis, vascular invasion was the only independent prognostic factor (OR=0.146, P=0.047).ConclusionVascular invasion is an independent risk factor for postoperative recurrence of early-stage lung adenocarcinoma with micropapillary/solid structure.
The hydrodynamic behavior of the perfusion process (cleaning) of the liver endovascular before the operation was studied to provide a theoretical guidance to the relative operations. A straight and a curved first-class vascular entity model with foreign matter and the control equations of turbulence liquid in vessel was established. With the physical parameters of a medical infusion liquid measured, an estimation method of perfusion parameters as an example, the perfusion velocity was proposed. The simulation was performed by changing technical parameters of the perfusion. Based on the control equations of turbulent liquid in vessel and the preliminarily calculated results using the vessel model, the results fitted the values of the real operation. The simulation results showed clearly the fluid dynamics behavior around the foreign matter, for example the swirling flow. The results also showed the distribution of velocity of the fluid and the wall pressure of the vessels. With the increasing velocity of the entrance perfusion, the pressure and the velocity field were increased in the two types of the vessel model. The negative wall pressure and recirculation region appeared and located in the foreign matter. Because of influence of the shape, the fluid dynamics behavior in the curved vessel model was more complicated than that in the straight vessel model. The swirling flow and the phenomenon of stagnation of the perfusion fluid were more likely to appear in the curved vessel than in the straight vessel. The most important conclusion of this paper is that the appropriate perfusion velocity can be esti-mated using the methods proposed in this paper.