Image quality assessment and feasibility of three-dimensional amide proton transfer-weighted imaging for hepatocellular carcinoma.

Background: With the continuous innovation of magnetic resonance imaging (MRI) hardware and software technology, amide proton transfer-weighted (APTw) imaging has been applied in liver cancer. However, to our knowledge, no study has evaluated the feasibility of a three-dimensional amide proton transfer-weighted (3D-APTw) imaging sequence for hepatocellular carcinoma (HCC). This study thus aimed to conduct an image quality assessment of 3D-APTw for HCC and to explore its feasibility. Methods: 3D-APTw MRI examinations were completed in 134 patients with clinically suspected HCC. According to the uniformity of APTw signal in the liver and within the lesion and the proportion of artifact and missing signal regions, APTw images were subjectively scored using a 5-point scale. The scanning success rate of liver APTw imaging was calculated as the ratio of the number of cases with a quality assurance measurement of more than 3 to the total number of HCC cases. The intra- and interobserver quality assurance measurements for APTw images were compared via the Kappa consistency test. Within the HCC cases with a minimum image quality threshold of 3 points, the APT values of HCC and the liver parenchyma, signal-to-noise ratio of APT-weighted images (SNRAPTw), and contrast-to-noise ratio of HCC (CNRHCC) were measured by two observers. The intra- and interobserver agreement was assessed using the intraclass correlation coefficient (ICC). The differences in APT values between HCC and liver parenchyma was determined using the Mann-Whitney test. Results: Sixty-six HCC cases with a quality assurance measurement of APTw imaging were included in the final analysis, and the calculated success rate was 70.21% (66/94). The subjective APT image quality scores of the two observers were consistent (3.66±1.18, 3.50±1.19, and 3.68±1.18), and no intergroup or intragroup statistical differences were found (P=0.594, and P=0.091), but the consistency of inter- and intraobserver was not as satisfactory (κ=0.594 and κ=0.580). The APT values in HCC lesion were significantly higher than those in liver parenchyma (2.73%±0.91% vs. 1.62%±0.55%; P<0.001). The APT values in HCC showed favorable intra- and interobserver consistency between the two observers (ICC =0.808 and ICC =0.853); the APT values in liver parenchyma, SNRAPTw, and CNRHCC values had moderate intraobserver consistency (ICC =0.578, ICC =0.568, and ICC =0.508) and interobserver consistency (ICC =0.599, ICC =0.199, and ICC =0.650). The coefficients of variation of the APTw values in the HCC lesion and in liver parenchyma were 33.4% and 34.4%, respectively. The SNRAPTw and CNRHCC were 30.75±18.74 and 3.56±3.19, with a coefficient of variation of 60.9% and 74.9%, respectively. Conclusions: Liver 3D-APTw imaging was preliminarily demonstrated to be clinically feasible for evaluating HCC.

Exploring the Underlying Correlation between the Structure and Ionic Conductivity in Halide Spinel Solid-State Electrolytes with Neutron Diffraction.

The development of cutting-edge solid-state electrolytes (SSEs) entails a deep understanding of the underlying correlation between the structure and ionic conductivity. Generally, the structure of SSEs encompasses several interconnected crystal parameters, and their collective influence on Li+ transport can be challenging to discern. Here, we systematically investigate the structure-function relationship of halide spinel LixMgCl2+x (2 ≥ x ≥ 1) SSEs. A nonmonotonic trend in the ionic conductivity of LixMgCl2+x SSEs has been observed, with the maximum value of 8.69 × 10-6 S cm-1 achieved at x = 1.4. The Rietveld refinement analysis, based on neutron diffraction data, has revealed that the crystal parameters including cell parameters, Li+ vacancies, Debye-Waller factor, and Li-Cl bond length assume diverse roles in influencing ionic conductivity of LixMgCl2+x at different stages within the range of x values. Besides, mechanistic analysis demonstrates Li+ transport along three-dimensional pathways, which primarily governs the contribution to ionic conductivity of LixMgCl2+x SSEs. This study has shed light on the collective influence of crystal parameters on Li+ transport behaviors, providing valuable insights into the intricate relationship between the structure and ionic conductivity of SSEs.

Image quality optimization: dynamic contrast-enhanced MRI of the abdomen at 3T using a continuously acquired radial golden-angle compressed sensing acquisition.

INTRODUCTION: The image quality of continuously acquired free-breathing Dynamic Contrast-Enhanced (DCE) golden-angle radial Magnetic Resonance Imaging (MRI) of abdomen suffers from motion artifacts and motion-related blurring. We propose a scheme by minimizing patients' motion status from breathing as well as optimizing the acquiring parameters to improve image quality and diagnostic performance of DCE-MRI with Golden-Angle Radial Sparse Parallel (GRASP) sequence of abdomen. METHODS: The optimization scheme follows two principles: (1) reduce the impact on images from unpredictable and irregulate motions during examination and (2) adjust the sequence parameters to increase the number of radial views in each partition. For the assessment of image quality, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), the severity of radial artifact, the degree of image sharpness, and a visual scoring of image quality with a 5-point scale were assessed. RESULTS: A total of 64 patients were included in this study before (16 men, 14 women, age: 54.9 ± 17.0) and after (18 men, 16 women, age: 58.6 ± 12.6) the optimization scheme was performed. The results showed that the SNR values of right and left lobe of liver in both plain phase and arterial phase were significantly increased (All P < 0.001) after the GRASP sequence been optimized. Significant improvements in CNR values were observed in the arterial phase (All P < 0.05). The significant differences in scores at each phase for visual scoring of image quality, noise of the right and left lobe of liver, radial artifact, and sharpness indicating that the image quality was significantly improved after the optimization (All P < 0.001). CONCLUSION: Our study demonstrated that the optimized scheme significantly improved the image quality of liver DCE-MRI with GRASP sequence both in plain and arterial phases. The optimized scheme of GRASP sequence could be a superior alternative to conventional approach for the assessment of liver.

Effect of grain boundary resistance on the ionic conductivity of amorphous xLi2S-(100-x)LiI binary system.

Solid-state electrolytes (SSEs) hold the key position in the progress of cutting-edge all-solid-state batteries (ASSBs). The ionic conductivity of solid-state electrolytes is linked to the presence of both amorphous and crystalline phases. This study employs the synthesis method of mechanochemical milling on binary xLi2S-(100-x)LiI system to investigate the effect of amorphization on its ionic conductivity. Powder X-ray diffraction (PXRD) shows that the stoichiometry of Li2S and LiI has a significant impact on the amorphization of xLi2S-(100-x)LiI system. Furthermore, the analysis of electrochemical impedance spectroscopy (EIS) indicates that the amorphization of xLi2S-(100-x)LiI system is strongly correlated with its ionic conductivity, which is primarily attributed to the effect of grain boundary resistance. These findings uncover the latent connections between amorphization, grain boundary resistance, and ionic conductivity, offering insight into the design of innovative amorphous SSEs.

Preoperative assessment of high-grade endometrial cancer using a radiomic signature and clinical indicators.

Aim: To develop and validate a radiomics-based combined model (ModelRC) to predict the pathological grade of endometrial cancer. Methods: A total of 403 endometrial cancer patients from two independent centers were enrolled as training, internal validation and external validation sets. Radiomic features were extracted from T2-weighted images, apparent diffusion coefficient map and contrast-enhanced 3D volumetric interpolated breath-hold examination images. Results: Compared with the clinical model and radiomics model, ModelRC showed superior performance; the areas under the receiver operating characteristic curves were 0.920 (95% CI: 0.864-0.962), 0.882 (95% CI: 0.779-0.955) and 0.881 (95% CI: 0.815-0.939) for the training, internal validation and external validation sets, respectively. Conclusion: ModelRC, which incorporated clinical and radiomic features, exhibited excellent performance in the prediction of high-grade endometrial cancer.

Accurate preoperative evaluation of the pathological grade of endometrial carcinoma is very important for the selection of treatment and prognosis. This study tried to develop a simple combined model based on radiomic features from endometrial carcinoma MRI and clinical features of patients. Compared with the clinical model and the radiomic model, the combined model showed superior performance. Therefore, this combined model would help patients and clinicians to make more rational decisions when choosing treatment strategies.

Dam deformation forecasting using SVM-DEGWO algorithm based on phase space reconstruction.

A hybrid model integrating chaos theory, support vector machine (SVM) and the difference evolution grey wolf optimization (DEGWO) algorithm is developed to analyze and predict dam deformation. Firstly, the chaotic characteristics of the dam deformation time series will be identified, mainly using the Lyapunov exponent method, the correlation dimension method and the kolmogorov entropy method. Secondly, the hybrid model is established for dam deformation forecasting. Taking SVM as the core, the deformation time series is reconstructed in phase space to determine the input variables of SVM, and the GWO algorithm is improved to realize the optimization of SVM parameters. Prior to this, the effectiveness of DEGWO algorithm based on the fusion of the difference evolution (DE) and GWO algorithm has been verified by 15 sets of test functions in CEC 2005. Finally, take the actual monitoring displacement of Jinping I super-high arch dam as examples. The engineering application examples show that the PSR-SVM-DEGWO model established performs better in terms of fitting and prediction accuracy compared with existing models.

Numerical Simulation of Flow and Temperature Fields in a Deep Stratified Reservoir Using Water-Separating Curtain.

In this work, the flow and temperature fields of a thermally stratified reservoir under different settings of a water-separating curtain are simulated by using the standard k-ε turbulence model. In the simulation, two different equations of state including Boussinesq approximation and the density-temperature function have been used and compared. This study shows that Boussinesq approximation is more time-saving, and the density-temperature function has higher computational accuracy. Thus, the standard k-ε turbulence model with two equations of state is applied to study the effect of adding a water-separating curtain in the stratified reservoir on the Discharged Water Temperature (DWT). It is found that adding the Water-Separating Curtain (WSC) can effectively increase the discharged water temperature. Moreover, the different arrangements of WSC have obvious effects on the discharged water temperature. For example, the increased temperature by adding a WSC with full sealing is 1 °C higher than that by using the WSC with a bottom opening height of 2 m. However, the maximum pressure difference acting on the WSC for the former WSC is 100 Pa higher than that for the latter WSC. In addition, this study shows that the different equations of state have little effect on the simulation results. Considering the calculation efficiency, equations of state using the Boussinesq approximation can be recommended to save the calculation time.

Effect of the degree of gastric filling on the measured thickness of advanced gastric cancer by computed tomography.

Imaging of gastric cancer thickness is closely associated with the depth of tumor invasion, which provides guidance for clinical staging and assists the evaluation of the effects of adjuvant therapy. However, it is unclear whether the measurement of thickness is affected by the degree of gastric filling, and its accuracy and reliability are under-reported. The present study aimed to investigate the influence of the degree of gastric filling on the measurement of gastric cancer thickness. A total of 38 patients with advanced gastric cancer who underwent enhanced abdominal computed tomography (CT) scanning at the Department of CT and MR in The Fourth Hospital of Hebei Medical University (Shijiazhuang, China) between July and September 2016 were recruited, consisting of 21 newly diagnosed cases and 17 follow-up cases following non-surgical treatments. Plain scanning (prior to filling) and enhanced scanning in venous phase (following filling) were performed. Axial CT images prior to and following filling of the normal part of gastric wall and the lesions were compared. The same procedure was repeated on these participants 1 month later by the same radiologist, and the results were compared with those obtained previously. Normal gastric wall thickness prior to and following gastric filling was significantly different (all P<0.001) with the most substantial changes observed at the greater curvature. Lesion thickness prior to and following filling was similar in newly diagnosed patients, but significantly different in patients for re-examination (P<0.05). The two thickness measurements in the same patients were consistent. The measured thickness of gastric cancer in newly diagnosed patients was relatively stable, and could be used as an indicator in baseline CT examination. Maintaining a similar degree of gastric filling during re-examination could aid the accurate evaluation of treatment efficacy.