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Stress detection of the conical frustum window is a very important issue to ensure the safety of deep manned submersibles. In this paper, we propose a method based on polarization imaging to evaluate the stress accumulation and recovery in the conical frustum window. An experimental setup of Mueller matrix polarimetry is built, and the samples are made by referring to the typical conical frustum windows in submersibles. By pressurizing different pressures on the samples, we can find the changes of their Mueller matrix images and further derived polarization parameters. The results show that the polarization parameters can characterize the stress transfer process and the elastic-plastic transformation process of the window under different pressurization pressures. We also use a two-layered wave plate model to simulate the stress distribution in the window, which reveals different performances of the former and latter layers of the window under pressurization. Finally, we use a finite element model to simulate and understand some of the above experimental results. This proposed method is expected to provide new possibilities for monitoring the window stress and further ensure the safety of deep manned submersibles.

Objective: To evaluate prospectively the efficacy and clinical significance of ultrasonography (US), helical computed tomography (HCT), endoscopic ultrasonography (EUS) and magnetic resonance imaging (MRI) in assessing locoregional invasion to the surrounding tissue or organs of primary pancreatic carcinoma., Methods: Sixty-eight consecutive patients with pancreatic carcinoma underwent US, HCT, EUS and MRI examinations before surgical exploration. All imaging results in terms of tumor size and locoregional invasion were assessed separately by two diagnostic radiologists and compared with the surgical and pathological findings., Results: Among the HCT, US, EUS and MRI examinations, EUS had the highest accuracy in assessing tumor size with a regression coefficient for the maximal and minimal diameter of 1.0250 (P = 0.0426) and 0.9873 (P < 0.0001), respectively. In the assessment of locoregional invasion to the surrounding tissue or organs, EUS also had the highest accuracy (75.8%) and sensitivity (80.0%), but MRI had the highest positive predicting value (97.4%). None of these four imaging techniques was significantly correlated with the surgical findings when analyzed by univariate logistic regression., Conclusion: Endoscopic ultrasonography may be the most useful imaging technique in assessing tumor size, but for assessing loco-regional invasion of primary pancreatic carcinoma, combination of more than one imaging techniques may be necessary.

Two neutralizing human scFv, b1 and h12 were identified initially using ELISA,employing highly purified virus as the coating antigen. The biosensor technique based on imaging ellipsometry was employed directly to detect two neutralizing monoclonal antibodies and serial serum samples from 10 SARS patients and 12 volunteers who had not SARS. Further, the kinetic process of interaction between the antibodies and SARS-CoV was studied using the real-time function of the biosensor. The biosensor is consistent with ELISA that the antibody h12 showed a higher affinity in encountering the virus than antibody b1. The affinity of antibody b1 and antibody h12 was 9.5 x 10(6) M(-1) and 1.36 x 10(7) M(- 1), respectively. As a label free method, the biosensor based on imaging ellipsometry proved to be a more competent mechanism for measuring serum samples from SARS patients and the affinity between these antibodies and the SARS coronavirus.

Purpose: To investigate the value of magnetic resonance imaging (MRI)-based radiomics in predicting the treatment response to concurrent chemoradiotherapy (CCRT) in patients with locally advanced cervical squamous cell cancer (LACSC). Methods: In total, 198 patients (training: n = 138; testing: n = 60) with LACSC treated with CCRT between January 2014 and December 2019 were retrospectively enrolled in this study. Responses were evaluated by MRI and clinical data performed at one month after completion of CCRT according to RECIST standards, and patients were divided into the residual group and nonresidual group. Overall, 200 radiomics features were extracted from T2-weighted imaging and apparent diffusion coefficient maps. The radiomics score (Rad-score) was constructed with a feature selection strategy. Logistic regression analysis was used for multivariate analysis of radiomics features and clinical variables. The performance of all models was assessed using receiver operating characteristic curves. Results: Among the clinical variables, tumor grade and FIGO stage were independent risk factors, and the areas under the curve (AUCs) of the clinical model were 0.741 and 0.749 in the training and testing groups. The Rad-score, consisting of 4 radiomics features selected from 200 radiomics features, showed good predictive performance with an AUC of 0.819 in the training group and 0.776 in the testing group, which were higher than the clinical model, but the difference was not statistically significant. The combined model constructed with tumor grade, FIGO stage, and Rad-score achieved the best performance, with an AUC of 0.857 in the training group and 0.842 in the testing group, which were significantly higher than the clinical model. Conclusion: MRI-based radiomics features could be used as a noninvasive biomarker to improve the ability to predict the treatment response to CCRT in patients with LACSC. [ABSTRACT FROM AUTHOR]

As an emerging technology that has attracted huge attention, non-line-of-sight (NLOS) imaging can reconstruct hidden objects by analyzing the diffuse reflection on a relay surface, with broad application prospects in the fields of autonomous driving, medical imaging, and defense. Despite the challenges of low signal-to-noise ratio (SNR) and high ill-posedness, NLOS imaging has been developed rapidly in recent years. Most current NLOS imaging technologies use conventional physical models, constructing imaging models through active or passive illumination and using reconstruction algorithms to restore hidden scenes. Moreover, deep learning algorithms for NLOS imaging have also received much attention recently. This paper presents a comprehensive overview of both conventional and deep learning-based NLOS imaging techniques. Besides, we also survey new proposed NLOS scenes, and discuss the challenges and prospects of existing technologies. Such a survey can help readers have an overview of different types of NLOS imaging, thus expediting the development of seeing around corners. [ABSTRACT FROM AUTHOR]

Purpose: To compare the diagnostic accuracies of MDCT and high-resolution MRI (HR-MRI) for regional nodal metastases with different short-axis diameter ranges in rectal cancer patients. Methods: Rectal adenocarcinoma patients who underwent both MDCT and HR-MRI before surgery were included. The maximum short-axis diameters of the nodes were measured, and were classified as benign or malignant on imaging findings. All of the nodes were subdivided as follows: ≤ 5 mm (Group A), > 5 mm and ≤ 10 mm (Group B) , and > 10 mm (Group C). The postoperative pathological reports were used as the standard, and the sensitivity, specificity, accuracy, ROC curve, and AUC value were calculated for each subgroup. Results: A total of 592 nodes were included in the node-to-node evaluation. In Group A, the specificity and accuracy of HR-MRI were significantly higher than those of MDCT (99.28% vs. 93.99%, P < 0.001; 95.78% vs. 89.56%, P = 0.010; respectively). In Group B, the specificity and accuracy of HR-MRI were also higher than those of MDCT (98.36% vs. 55.74%, P < 0.001; 80.45% vs. 66.17%, P < 0.001; respectively). For Groups A and B, the AUCs of MDCT were both 0.65, whereas those of HR-MRI were 0.76 and 0.82, respectively. In Group C, all nine malignant nodes were correctly diagnosed metastases on MDCT, whereas one was misjudged as benign on HR-MRI. Conclusions: The diagnostic value of HR-MRI is superior to that of MDCT, with higher specificity, accuracy, and AUC values for HR-MRI than for MDCT. [ABSTRACT FROM AUTHOR]

Background: Intravoxel incoherent motion magnetic resonance imaging (IVIM-MRI) acquires tumor perfusion information without injection of contrast medium, which is promising in tumor assessment. However, its consistency with dynamic contrast-enhanced MRI (DCE-MRI), a more widely used method for tumor perfusion evaluation, is not revealed in rectal cancer.Purpose: In this study, we aimed to investigate the correlation of perfusion-sensitive parameters derived from IVIM-MRI with DCE-MRI and measurement reproducibility of IVIM-MRI parameters in rectal cancer.Material and Methods: Forty-seven rectal cancer patients underwent IVIM-MRI with 16 b-values and DCE-MRI. The perfusion fraction ( f), pseudo-diffusion coefficient ( D*), and f· D* were measured by two radiologists independently and correlated with the transfer constant ( Ktrans), reflux constant ( kep), and extravascular extracellular fractional volume ( ve) obtained from DCE-MRI.Results: Pearson's correlation analyses of IVIM-MRI and DCE-MRI parameters showed fair to moderate correlation between f and Ktrans ( r = 0.461, P = 0.001), followed by f and kep ( r = 0.430, P = 0.003), f·D*, and Ktrans ( r = 0.425, P = 0.003), f·D*, and kep ( r = 0.384, P = 0.008). There was no significant correlation between ve and f, ve and D*, ve and f· D*, D* and Ktrans, and D* and kep. The reproducibility of IVIM-MRI measurements was moderate. For parameter f, intraclass correlation coefficient (ICC) = 0.71 (0.53-0.82), coefficient of variation (CV) = 13.05 ± 0.02%, limit of agreement (LoA) = -0.05-0.04; for parameter D*, ICC = 0.55 (0.32-0.72), CV = 20.28 ± 3.23%, LoA = -9.6-8.4.Conclusion: Perfusion-sensitive parameters derived from IVIM-MRI correlated fairly to moderately with DCE-MRI in rectal cancer patients and showed moderate measurement reproducibility. IVIM-MRI supplements routine high-resolution MRI without contrast enhancement to provide information of tumor microcirculation. [ABSTRACT FROM AUTHOR]

We propose in this paper an automatic method for early diagnosis of cirrhosis using high-frequency ultrasound images. Instead of analyzing image texture, our method exploits image characteristics of liver capsule. To this end, we first propose a novel spatial context-constrained multi-scale method to accurately extract the boundaries of the liver capsule. Our approach detects all the possible edges in scale space, and the irrelevant edges are then filtered out with a spatial context-based energy function. Secondly on this basis, two novel descriptors are proposed to characterize the geometric properties of liver capsule and the changes of liver capsule with the aggravation of liver cirrhosis. These two descriptors are used as features fed into a support vector machine classifier for quantitative analysis in automatic diagnosis. Experiment results show that the proposed method can reliably localize liver capsule and accurately classify ultrasound liver images into normal and cirrhosis classes automatically. [ABSTRACT FROM AUTHOR]

Objectives: To investigate the potential of various metrics derived from mono-exponential model (MEM), bi-exponential model (BEM) and stretched exponential model (SEM)-based diffusion-weighted imaging (DWI) in diagnosing and differentiating the pathological subtypes and grades of uterine cervical carcinoma.Methods: 71 newly diagnosed patients with cervical carcinoma (50 cases of squamous cell carcinoma [SCC] and 21 cases of adenocarcinoma [AC]) and 32 healthy volunteers received DWI with multiple b values. The apparent diffusion coefficient (ADC), pure molecular diffusion (D), pseudo-diffusion coefficient (D*), perfusion fraction (f), water molecular diffusion heterogeneity index (alpha), and distributed diffusion coefficient (DDC) were calculated and compared between tumour and normal cervix, among different pathological subtypes and grades.Results: All of the parameters were significantly lower in cervical carcinoma than normal cervical stroma except alpha. SCC showed lower ADC, D, f and DDC values and higher D* value than AC; D and DDC values of SCC and ADC and D values of AC were lower in the poorly differentiated group than those in the well-moderately differentiated group.Conclusion: Compared with MEM, diffusion parameters from BEM and SEM may offer additional information in cervical carcinoma diagnosis, predicting pathological tumour subtypes and grades, while f and D showed promising significance.Key Points: • DWI-derived parameters by different models are related but provide diversified information. • Commonly used ADC by MEM of DWI overestimates the tissue water diffusivity. • DWI processed by BEM could separate blood perfusion from true diffusion effects. • The derived diffusion-related and perfusion-related parameters by BEM are superior to ADC. [ABSTRACT FROM AUTHOR]

Objective To analyze the application of hybrid treatment for complicated carotid artery stenosis and occlusion and explore its clinical significance. Methods The clinical data of 12 patients, including 8 carotid artery occlusion patients and 4 multilevel carotid artery stenosis patients, who received hybrid treatment during the surgery were analyzed, and the efficacy and safety of combined surgical techniques were explored. Results For 8 carotid artery occlusion patients, 7 procedures were successful. For 4 multilevel carotid artery stenosis patients, all procedures were successful. They underwent both carotid endartertectomy (CEA) and common carotid artery angioplasty during the surgery. There was no neurological morbidity or mortality after operation. Conclusions Intraoperative angioplasty combined with CEA (hybrid treatment) is an effective and safe method for carotid artery occlusion or multilevel carotid artery stenosis. [ABSTRACT FROM AUTHOR]

Objective To explore the causes of aggravation of microcirculation disorders in the process of intravenous thrombolysis with alteplase and the clinical outcomes. Methods The clinical data of the aggravated signs and symptoms of 13 cases treated by alteplase were reported, and the onset characteristics and clinical outcomes were analysed to summarize emergency experiences. Results There were 13 patients with stenosis of intracranial large arteries occurred perforating branch infarctions caused by the blocking of carried arteries (8 cases in internal carotid system, 5 cases in vertebral-basilar system). In the process of thrombolytic therapy, main aggravated presentations including cortical ischemic symptom, quadriplegia, exacerbated disturbance of consciousness were seen. Imaging examinations showed multiple new petechial ischemic foci in cortex and watershed region or increasing of infarct foci in cerebellum and brain stem. The prognosis was favorable after expectant treatment. NIHSS score was 8.69 ± 3.42 at 24 h after treatment, and mRS score was 0.94 ± 0.37 at 3 month-follow-up. Neurologic deficit and quality of life were evidently improved. Conclusion In the course of intravenous thrombolytic therapy with alteplase. Aggravated clinical signs and symptoms may be related to various factors. Emboli disintegration inducing microcirculation disorder is inferred to be the main cause. For patients presenting aggravated signs and symptoms in thrombolysis process, favorable outcomes may occur as long as intensive care and timely treatment are performed. [ABSTRACT FROM AUTHOR]

This study aims to explore computed tomography (CT) and magnetic resonance imaging (MRI) features of patients diagnosed with primary cardiac angiosarcoma. The study involved the analysis of 12 patients diagnosed with primary cardiac angiosarcoma who underwent non-contrast (8/12) or contrast-enhanced CT (10/12) or MRI (4/12). Imaging appearances, including the tumor location and adjacent infiltration, were analyzed. All 12 lesions were located in the right atrium with a broad base. Adjacent invasion including the tricuspid valve and right ventricle (2/12), inferior or superior vena cava (2/12), pericardium (10/12), and right coronary artery (7/12) was common. On unenhanced CT scans, tumors in two patients were homogeneous in density, whereas the others were inhomogeneous. Ten patients showed heterogeneous enhancement. The enhancement pattern showed no direct correlation with the differentiation degree of the tumor. Four lesions manifested as heterogeneous intensity, with hyperintense hemorrhage foci on both T1- and T2-weighted MRI. Three showed rim enhancement and one showed patchy enhancement. Primary cardiac angiosarcoma often involves the right side of the heart with infiltration of peripheral structures. CT features include typical inhomogeneous density on unenhanced scans and heterogeneous centripetal enhancement on enhanced scans. A cauliflower-like appearance on both T1- and T2-weighted MRI is common. The characteristic enhancement pattern of MRI remains to be determined. [ABSTRACT FROM AUTHOR]

In order to improve the diagnostic accuracy of colon cancer, a novel classification algorithm based on sub-patch weight color histogram and improved SVM is proposed, which has good approximation ability for complex pathological image. Our proposed algorithm combines wavelet kernel SVM with color histogram to classify pathological image. Firstly, the pathological image is divided into non-overlapping sub-patches, and the features of sub-patch histogram are extracted. Then, the global and local features are fused by the sub-patch weighting algorithm. Then, the RelicfF based forward selection algorithm is used to integrate color features and texture features so as to enhance the characterization capabilities of the tumor cell. Finally, Morlet wavelet kernel-based least squares support vector machine method is adopted to enhance the generalization ability of the model for small sample with non-linear and high-dimensional pattern classification problems. Experimental results show that the proposed pathological diagnostic algorithm can gain higher accuracy compared with existing comparison algorithms. [ABSTRACT FROM AUTHOR]

• A misdiagnosed case of Rickettsia felis encephalitis was confirmed by cerebrospinal fluid mNGS. • Neuroimaging showed a focal lesion in the right thalamus which was indistinguishable from a glioma. • Perivascular inflammation in the lesion implied a vasophilic characteristic of the pathogen. • Rickettsia felis encephalitis could clinically display as none-specific neurological symptoms. Rickettsia felis (R. felis) infection is a cause of unspecified encephalitis. However, the incidence has been underestimated due to the intracellular features of the pathogen and insufficient understanding of its clinical picture. This study reported a case of R. felis infection in a 26-year-old female who only manifested with certain neurological symptoms. With a lack of specific systemic inflammatory symptoms, the diagnosis was initially misdiagnosed as a brain glioma. However, a brain tissue biopsy showed prominent perivascular inflammatory infiltrations, which indicated inflammatory disease. Spinal fluid metagenomic next-generation sequencing (mNGS) was taken after ruling out other common infectious and autoimmune diseases. The results suggested R. felis infection, which was also supported by Weil-Felix reaction in the serum. After the diagnosis was corrected as R. felis encephalitis, the patient was successfully treated with doxycycline and had a good prognosis at the 1-year follow-up. [ABSTRACT FROM AUTHOR]