Search

Abstract Background We investigated the potential of magnetic resonance elastography (MRE) stiffness measurements in skeletal muscles as an outcome measure, by determining its test–retest reliability, as well as its sensitivity to change in a longitudinal follow‐up study. Methods We assessed test–retest reliability of muscle MRE in 20 subjects with (n = 5) and without (n = 15) muscle diseases and compared this to Dixon proton density fat fraction (PDFF) and volume measurements. Next, we measured MRE muscle stiffness in 21 adults with Becker muscular dystrophy (BMD) and 21 age‐matched healthy controls at baseline, and after 9 and 18 months. We compared two different methods of analysing MRE data in this study: ‘Method A’ used the stiffness maps generated by the Philips MRE software, and ‘Method B’ applied a custom‐made procedure based on wavelength measurements on the MRE images. Results Intraclass correlation coefficients (ICC) of muscle stiffness ranged from good (0.83 for left vastus medialis, P 0.050 for all). The ICC of muscle PDFF and volume measurements was excellent (>0.90; P

A retrospective analysis was conducted to investigate how a bright luminal sign on high b-value diffusion-weighted imaging (DWI) could be considered as a new biomarker for identifying fibrotic strictures in Crohn's disease (CD). Fibrotic strictures, due to excessive deposition of extracellular matrix following chronic inflammatory processes, can be difficult to distinguish from inflammatory strictures using endoscopy. This study was performed on 65 patients with CD who underwent MRE, and among them 32 patients showed the bright luminal sign on high b-value DWI. DWI findings were compared to pre- and post-contrast MRE data. Luminal bright sign performance results were calculated using a confusion matrix, the relationship between categorical variables was assessed by the χ2 test of independence, and the Kruskal–Wallis test (ANOVA) was used for the assessment of statistical significance of differences between groups. The results indicated a high sensitivity (90%) and specificity (85%) of the bright luminal sign for fibro-stenotic CD and a significant correlation between DWI luminal brightness and markers such as the homogeneous enhancement pattern (p < 0.001), increase in enhancement percentage from 70 s to 7 min after gadolinium injection (p < 0.001), and submucosal fat penetration (p = 0.05). These findings indicate that DWI hyperintensity can be considered as a good non-invasive indicator for the detection of severe intestinal fibrosis and may provide an efficient and accurate method for assessing fibrotic strictures. This new non-invasive biomarker could allow an early diagnosis of fibrotic stricture, delaying the onset of complications and subsequent surgery. Moreover, further evaluations through larger prospective trials with histopathological correlation are needed to confirm these results and completely determine the clinical benefits of DWI in treating CD. [ABSTRACT FROM AUTHOR]

Magnetic resonance elastography (MRE) is a rapidly developing medical imaging technique that allows for quantitative assessment of the biomechanical properties of the tissue. MRE is now regarded as the most accurate noninvasive test for detecting and staging liver fibrosis. A two-dimensional (2D MRE) acquisition version is currently deployed at >2000 locations worldwide. 2D MRE allows for the evaluation of the magnitude of the complex shear modulus, also referred to as stiffness. The development of 3D vector MRE has enabled researchers to assess the biomechanical properties of small organs where wave propagation cannot be adequately analyzed with the 2D MRE imaging approach used in the liver. In 3D vector MRE, the shear waves are imaged and processed throughout a 3D volume and processed with an algorithm that accounts for wave propagation in any direction. Additionally, the motion is also imaged in x, y, and z directions at each voxel, allowing for more advanced processing to be applied. This review describes the technical principles of 3D vector MRE, surveys its clinical applications in small organs, and discusses potential clinical significance of 3D vector MRE. 3D vector MRE is a promising tool for characterizing the biomechanical properties of small organs such as the uterus, pancreas, thyroid, prostate, and salivary glands. However, its potential has not yet been fully explored. [Display omitted] • 3D Vector MRE has high clinical potential for the assessment of small organs. • 3D Vector MRE of the uterus, pancreas, thyroid, prostate, and parotid is feasible. • 3D Vector MRE provides information on the biomechanical properties of small organs. • 3D Vector MRE helps to differentiate between healthy and pathological tissue. • More research is needed to optimize the performance of 3D Vector MRE in small organs. [ABSTRACT FROM AUTHOR]

Aim: To compare hepatic stiffness and fat fraction in patients with obesity and type 1 diabetes (T1D) with type 2 diabetes (T2D) with a similar body mass index (BMI). Methods: In this prospective cross‐sectional study, 90 participants with T1D (BMI 30.5 ± 4.5 kg/m2; diabetes duration 20.5 ± 9.8 years; HbA1c 8.2% ± 1.4%) and 69 with T2D (BMI: 30.8 ± 4.6 kg/m2; diabetes duration: 11.7 ± 7.8 years; HbA1c: 7.3% ± 1.4%) were included. Liver fat fraction and stiffness were examined by magnetic resonance imaging and elastography, respectively. Logistic regressions were used to evaluate associations with biomedical variables. Results: The mean liver stiffness score in patients with obesity and T1D was 2.2 ± 0.5 kPa, while in T2D it was 2.6 ± 0.8 kPa (P <.001). The liver fat fraction in patients with obesity and T1D was 3.7% ± 6.3%, and in T2D it was 10.6% ± 7.9% (P <.001). Metabolic dysfunction‐associated steatotic liver disease (MASLD) was present in 13.3% of patients with T1D and in 69.6% of patients with T2D, whereas fibrosis was suggested in 7.8% of patients with T1D and in 27.5% of patients with T2D. Liver stiffness was four times higher in patients with T2D compared with those with T1D (odds ratio = 5.4, 95% confidence interval: 2.1‐13.6, P <.001). Aspartate transaminase (AST), alanine transaminase, gamma‐glutamyl transferase (GGT), triglycerides and the android‐to‐gynoid ratio were associated with elevated fat fraction in both cohorts. AST and GGT were associated with elevated liver stiffness in both cohorts. Conclusions: Patients with obesity and T1D had lower liver fat and liver stiffness compared with those patients with T2D, despite similar levels of BMI, a longer duration of diabetes and worse glycaemic control. [ABSTRACT FROM AUTHOR]

Crohn's disease (CD) poses significant morbidity, underscoring the need for effective, non-invasive inflammatory assessment using magnetic resonance enterography (MRE). This literature review evaluates recent publications on the role of deep learning in improving MRE for CD assessment. We searched MEDLINE/PUBMED for studies that reported the use of deep learning algorithms for assessment of CD activity. The study was conducted according to the PRISMA guidelines. The risk of bias was evaluated using the QUADAS‐2 tool. Five eligible studies, encompassing 468 subjects, were identified. Our study suggests that diverse deep learning applications, including image quality enhancement, bowel segmentation for disease burden quantification, and 3D reconstruction for surgical planning are useful and promising for CD assessment. However, most of the studies are preliminary, retrospective studies, and have a high risk of bias in at least one category. Future research is needed to assess how deep learning can impact CD patient diagnostics, particularly when considering the increasing integration of such models into hospital systems. [ABSTRACT FROM AUTHOR]

Magnetorheological elastomers (MREs) are intelligent materials that exhibit changes in their properties when exposed to a magnetic field. By applying a magnetic field during the curing process, MRE can be made anisotropic. This study focuses on optimizing the fabrication process parameters using the design of an experimental approach, namely the Taguchi method. The parameters to be optimized for MRE fabrication include the number of coil turns, coil diameter, curing current, and curing time. Twenty-five sets of anisotropic MRE were fabricated and subjected to drop impact testing to evaluate their impact absorption capability. The results were further examined for a more comprehensive analysis using the signal-to-noise ratio, analysis of means, and analysis of variance. This rigorous examination aimed to pinpoint the optimal parameters and the key factors influencing the fabrication of the MRE. From the analysis result, it can be seen that the number of coil turns contributed to 63.36% of the entire MRE fabrication process. Furthermore, a well-defined composition for the MRE was identified, consisting of 200 coil turns, a coil diameter of 1.0 mm, an applied current of 1.2 A, and a curing time of 20 min.

Background & aimsFALCON 1 was a phase IIb study of pegbelfermin in patients with non-alcoholic steatohepatitis (NASH) and stage 3 fibrosis. This FALCON 1 post hoc analysis aimed to further assess the effect of pegbelfermin on NASH-related biomarkers, correlations between histological assessments and non-invasive biomarkers, and concordance between the week 24 histologically assessed primary endpoint response and biomarkers.MethodsBlood-based composite fibrosis scores, blood-based biomarkers, and imaging biomarkers were evaluated for patients with available data from FALCON 1 at baseline through week 24. SomaSignal tests assessed protein signatures of NASH steatosis, inflammation, ballooning, and fibrosis in blood. Linear mixed-effect models were fit for each biomarker. Correlations and concordance were assessed between blood-based biomarkers, imaging, and histological metrics.ResultsAt week 24, pegbelfermin significantly improved blood-based composite fibrosis scores (ELF, FIB-4, APRI), fibrogenesis biomarkers (PRO-C3 and PC3X), adiponectin, CK-18, hepatic fat fraction measured by MRI-proton density fat fraction, and all four SomaSignal NASH component tests. Correlation analyses between histological and non-invasive measures identified four main categories: steatosis/metabolism, tissue injury, fibrosis, and biopsy-based metrics. Concordant and discordant effects of pegbelfermin on the primary endpoint vs. biomarker responses were observed; the most clear and concordant effects were on measures of liver steatosis and metabolism. A significant association between hepatic fat measured histologically and by imaging was observed in pegbelfermin arms.ConclusionsPegbelfermin improved NASH-related biomarkers most consistently through improvement of liver steatosis, though biomarkers of tissue injury/inflammation and fibrosis were also improved. Concordance analysis shows that non-invasive assessments of NASH support and exceed the improvements detected by liver biopsy, suggesting that greater consideration should be given to the totality of available data when evaluating the efficacy of NASH therapeutics.Clinical trial numberPost hoc analysis of NCT03486899.Impact and implicationsFALCON 1 was a study of pegbelfermin vs. placebo in patients with non-alcoholic steatohepatitis (NASH) without cirrhosis; in this study, patients who responded to pegbelfermin treatment were identified through examination of liver fibrosis in tissue samples collected through biopsy. In the current analysis, non-invasive blood- and imaging-based measures of fibrosis, liver fat, and liver injury were used to determine pegbelfermin treatment response to see how they compared with the biopsy-based results. We found that many of the non-invasive tests, particularly those that measured liver fat, identified patients who responded to pegbelfermin treatment, consistent with the liver biopsy findings. These results suggest that there may be additional value in using data from non-invasive tests, along with liver biopsy, to evaluate how well patients with NASH respond to treatment.

Background & aimsLean patients with non-alcoholic fatty liver disease (NAFLD) represent 10-20% of the affected population and may have heterogeneous drivers of disease. We have recently proposed the evaluation of patients with lean NAFLD without visceral adiposity for rare monogenic drivers of disease. Here, we aimed to validate this framework in a well-characterised cohort of patients with biopsy-proven NAFLD by performing whole exome sequencing.MethodsThis prospective study included 124 patients with biopsy-proven NAFLD and paired liver biopsies who underwent standardised research visits including advanced magnetic resonance imaging (MRI) assessment of liver fat and stiffness.ResultsSix patients with lean NAFLD were identified and underwent whole exome sequencing. Two lean patients (33%) were identified to have monogenic disorders. The lean patients with monogenic disorders had similar age, and anthropometric and MRI characteristics to lean patients without a monogenic disorder. Patient 1 harbours a rare homozygous pathogenic mutation in ALDOB (aldolase B) and was diagnosed with hereditary fructose intolerance. Patient 2 harbours a rare heterozygous mutation in apolipoprotein B (APOB). The pathogenicity of this APOB variant (p.Val1856CysfsTer2) was further validated in the UK Biobank and associated with lower circulating APOB levels (beta = -0.51 g/L, 95% CI -0.65 to -0.36 g/L, p = 1.4 × 10-11) and higher liver fat on MRI (beta = +10.4%, 95% CI 4.3-16.5%, p = 8.8 × 10-4). Hence, patient 2 was diagnosed with heterozygous familial hypobetalipoproteinaemia.ConclusionsIn this cohort of well-characterised patients with lean NAFLD without visceral adiposity, 33% (2/6) had rare monogenic drivers of disease, highlighting the importance of genomic analysis in this NAFLD subtype.Impact and implicationsAlthough most people with non-alcoholic fatty liver disease (NAFLD) are overweight or obese, a subset are lean and may have unique genetic mutations that cause their fatty liver disease. We show that 33% of study participants with NAFLD who were lean harboured unique mutations that cause their fatty liver, and that these mutations had effects beyond the liver. This study demonstrates the value of genetic assessment of NAFLD in lean individuals to identify distinct subtypes of disease.

In the face of escalating credit card fraud due to the surge in e-commerce activities, effectively distinguishing between legitimate and fraudulent transactions has become increasingly challenging. To address this, various machine learning (ML) techniques have been employed to safeguard cardholders and financial institutions. This article explores the use of the Ensemble Hidden Markov Model (EHMM) combined with two distinct feature extraction methods: principal component analysis (PCA) and a proposed statistical feature set termed MRE, comprising Mean, Relative Amplitude, and Entropy. Both the PCA-EHMM and MRE-EHMM approaches were evaluated using a dataset of European cardholders and demonstrated comparable performance in terms of recall (sensitivity), specificity, precision, and F1-score. Notably, the MRE-EHMM method exhibited significantly reduced computational complexity, making it more suitable for real-time credit card fraud detection. Results also demonstrated that the PCA and MRE approaches perform significantly better when integrated with the EHMM in contrast to the conventional HMM approach. In addition, the proposed MRE-EHMM and PCA-EHMM techniques outperform other classic ML models, including random forest (RF), linear regression (LR), decision trees (DT) and K-nearest neighbour (KNN). [ABSTRACT FROM AUTHOR]

In this article, the performance of mechanical resistance against failure of mechanical structures under bending load was studied by the use of a hybrid sandwich composite (Magnetorheological Elastomer (MRE) – honeycomb). Accordingly, a series of four-point bending mechanical tests were carried out. In addition, a comparison of the force-deflection responses, the values of the maximum forces supported by each sample before damage were determined. Through the additional effect of the MRE core, the hybrid sandwich composite samples presented the best performances in terms of energy absorption-dissipation, and thanks to the effect of the honeycomb part, the Hybrid sandwich composite samples presented the best performance in terms of mechanical strength. To validate the performance of these developed hybrid structures, the numerical results are compared with the corresponding experimental results. [ABSTRACT FROM AUTHOR]

Purpose: Abnormal adherence at functional myofascial interfaces is hypothesized as an important phenomenon in myofascial pain syndrome. This study aimed to investigate the feasibility of MR elastography (MRE)–based slip interface imaging (SII) to visualize and assess myofascial mobility in healthy volunteers. Methods: SII was used to assess local shear strain at functional myofascial interfaces in the flexor digitorum profundus (FDP) and thighs. In the FDP, MRE was performed at 90 Hz vibration to each index, middle, ring, and little finger. Two thigh MRE scans were performed at 40 Hz with knees flexed and extended. The normalized octahedral shear strain (NOSS) maps were calculated to visualize myofascial slip interfaces. The entropy of the probability distribution of the gradient NOSS was computed for the two knee positions at the intermuscular interface between vastus lateralis and vastus intermedius, around rectus femoris, and between vastus intermedius and vastus medialis. Results: NOSS map depicted distinct functional slip interfaces in the FDP for each finger. Compared to knee flexion, clearer slip interfaces and larger gradient NOSS entropy at the vastus lateralis–vastus intermedius interface were observed during knee extension, where the quadriceps are not passively stretched. This suggests the optimal position for using SII to visualize myofascial slip interface in skeletal muscles is when muscles are not subjected to any additional force. Conclusion: The study demonstrated that MRE‐based SII can visualize and assess myofascial interface mobility in extremities. The results provide a foundation for investigating the hypothesis that myofascial pain syndrome is characterized by changes in the mobility of myofascial interfaces. [ABSTRACT FROM AUTHOR]

This paper introduces an electromagnetic structure utilizing the controllable mechanical properties of magnetorheological elastomer (MRE) materials through magnetic flux. An adaptive elastic foundation composed of these materials is explored for vibration reduction and frequency modulation. This study investigates these effects using both a single-mass model and a coupled human–seat model. For objects supported by the adaptive elastic foundation, increasing the magnetic flux enhances the stiffness and damping, thereby significantly reducing the peak response while slightly increasing the resonance frequency. Strategies such as increasing the magnetic flux, reducing the object mass, and minimizing the system's degrees of freedom and internal damping contribute to enhancing the vibration reduction and frequency modulation in the adaptive elastic foundation. The simulation results indicate that for a seated human (weighing between 72.4 kg and 88.4 kg), the adaptive elastic foundation reduces the head peak response by approximately 15.7% and increases the resonance frequency by approximately 3.4% at a magnetic flux of 138 mT. [ABSTRACT FROM AUTHOR]

Magnetic resonance elastography (MRE) and diffusion-weighted imaging (DWI) are complementary imaging techniques that detect disease based on viscoelasticity and water mobility, respectively. However, the relationship between viscoelasticity and water diffusion is still poorly understood, hindering the clinical translation of combined DWI-MRE markers. We used DWI-MRE to study 129 biomaterial samples including native and cross-linked collagen, glycosaminoglycans (GAGs) with different sulfation levels, and decellularized specimens of pancreas and liver, all with different proportions of solid tissue, or solid fractions. We developed a theoretical framework of the relationship between mechanical loss and tissue-water mobility based on two parameters, solid and fluid viscosity. These parameters revealed distinct DWI-MRE property clusters characterizing weak, moderate, and strong water-network interactions. Sparse networks interacting weakly with water, such as collagen or diluted decellularized tissue, resulted in marginal changes in water diffusion over increasing solid viscosity. In contrast, dense networks with larger solid fractions exhibited both free and hindered water diffusion depending on the polarity of the solid components. For example, polar and highly sulfated GAGs as well as native soft tissues hindered water diffusion despite relatively low solid viscosity. Our results suggest that two fundamental properties of tissue networks, solid fraction and network polarity, critically influence solid and fluid viscosity in biological tissues. Since clinical DWI and MRE are sensitive to these viscosity parameters, the framework we present here can be used to detect tissue remodeling and architectural changes in the setting of diagnostic imaging. The viscoelastic properties of biological tissues provide a wealth of information on the vital state of cells and host matrix. Combined measurement of viscoelasticity and water diffusion by medical imaging is sensitive to tissue microarchitecture. However, the relationship between viscoelasticity and water diffusion is still poorly understood, hindering full exploitation of these properties as a combined clinical biomarker. Therefore, we analyzed the parameter space accessible by diffusion-weighted imaging (DWI) and magnetic resonance elastography (MRE) and developed a theoretical framework for the relationship between water mobility and mechanical parameters in biomaterials. Our theory of solid material properties related to particle motion can be translated to clinical radiology using clinically established MRE and DWI. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract Background Crohn’s disease is a chronic inflammatory bowel disease that can affect any part of the gut. Endoscopy is the gold standard for diagnosis, but it only assesses mucosal lesions. Magnetic resonance enterography (MRE) can assess disease presence and activity, but it has limitations such as motion sensitivity, long scan time, and high cost. Bowel sonography has been introduced as a non-invasive, practical, safe, and low-cost technique to assess disease activity and complications. In our study we aim to assess the comparability of ultrasound to MRE in evaluation of patients with Crohn’s disease, and its complications. Results Twenty-five patients with 38 Crohn’s disease affected segments were evaluated by bowel ultrasound (BUS) and MRI enterography (MRE), where BUS and MRE showed equivalent diagnostic performance for disease detection and localization (97.4%, 100%), for sensitivity and specificity of both modalities. Peri-mural fluid (89.5%, 94.4%) and mural stratification loss (100%, 100%) showed high sensitivity and specificity by BUS compared to MRE, while for assessment of mural vascularity, BUS showed high sensitivity and specificity for high grade vascularity (100%, 83.3%), but low sensitivity and high specificity for low and moderate vascularity (0%–62.5%, 81.8%) compared to MRE. Complications including fistulae and abscessed were all correctly identified in BUS compared to MRE. Conclusion BUS showed comparable results to MRE for identification, localization, assessment of findings related to disease activity, and complications in cases of Crohn’s disease rendering it a viable alternative to MRE.

Background: Crohn's disease is a chronic inflammatory bowel disease that can affect any part of the gut. Endoscopy is the gold standard for diagnosis, but it only assesses mucosal lesions. Magnetic resonance enterography (MRE) can assess disease presence and activity, but it has limitations such as motion sensitivity, long scan time, and high cost. Bowel sonography has been introduced as a non-invasive, practical, safe, and low-cost technique to assess disease activity and complications. In our study we aim to assess the comparability of ultrasound to MRE in evaluation of patients with Crohn's disease, and its complications. Results: Twenty-five patients with 38 Crohn's disease affected segments were evaluated by bowel ultrasound (BUS) and MRI enterography (MRE), where BUS and MRE showed equivalent diagnostic performance for disease detection and localization (97.4%, 100%), for sensitivity and specificity of both modalities. Peri-mural fluid (89.5%, 94.4%) and mural stratification loss (100%, 100%) showed high sensitivity and specificity by BUS compared to MRE, while for assessment of mural vascularity, BUS showed high sensitivity and specificity for high grade vascularity (100%, 83.3%), but low sensitivity and high specificity for low and moderate vascularity (0%–62.5%, 81.8%) compared to MRE. Complications including fistulae and abscessed were all correctly identified in BUS compared to MRE. Conclusion: BUS showed comparable results to MRE for identification, localization, assessment of findings related to disease activity, and complications in cases of Crohn's disease rendering it a viable alternative to MRE. [ABSTRACT FROM AUTHOR]

Purpose: To demonstrate a novel MR elastography (MRE) technique, termed here wavelet MRE. With this technique, broadband motion sensitivity is achievable. Moreover, the true tissue displacement can be reconstructed with a simple inverse transform. Methods: A wavelet MRE sequence was developed with motion‐encoding gradients based on Haar wavelets. From the phase images' displacement was estimated using an inverse transform. Simulations were performed using a frequency sweep and a transient as ground‐truth motions. A PVC phantom was scanned using wavelet MRE and standard MRE with both transient (one and 10 cycles of 90‐Hz motion) and steady‐state dual‐frequency motion (30 and 60 Hz) for comparison. The technique was tested in a human brain, and motion trajectories were estimated for each voxel. Results: In simulation, the displacement information estimated from wavelet MRE closely matched the true motion. In the phantom test, the MRE phase data generated from the displacement information derived from wavelet MRE agreed well with standard MRE data. Testing of wavelet MRE to assess transient motion waveforms in the brain was successful, and the tissue motion observed was consistent with a previous study. Conclusion: The uniform and broadband frequency response of wavelet MRE makes it a promising method for imaging transient, multifrequency motion, or motion with unknown frequency content. One potential application is measuring the response of brain tissue undergoing low‐amplitude, transient vibrations as a model for the study of traumatic brain injury. [ABSTRACT FROM AUTHOR]

Introduction: Recent investigations into the biomechanics of the brain have unveiled alteration in tissue stiffness triggered by external stimuli. For instance, visual stimulation effects can be measured in elasticity images of the cortex generated by functional magnetic resonance elastography (MRE). Such a mechanical characterization method combined with non-invasive brain stimulation (NIBS), a technique that seeks to selectively modulate particular parts of the brain using weak electrical currents, has the potential to influence research on various neurological disorders. In this in silico study, we aimed to elucidate individual and interdependent aspects related to a synchronized biomechanical imaging and non-invasive brain stimulation methodology. Magnetic resonance electrical impedance tomography (MREIT) was incorporated to the pipeline, providing a promising way of evaluating NIBS-induced electrical current patterns in the brain while leveraging MRE and transcranial alternating current stimulation (tACS) experimental settings. Methods: A mouse head model was assembled using open-access atlases to include five anatomical structures: skin/subcutaneous tissue, skull, cerebrospinal fluid (CSF), brain white and grey matters. MRE, tACS, and MREIT experiments were simulated using Comsol Multiphysics with Matlab Livelink. Synthetic MRE and MREIT data were processed using the subzone non-linear inversion and harmonic B[sub z] algorithm, respectively, to reconstruct images of the distributed complex shear modulus and electrical conductivity. Results and Discussion: Lorentz body forces arising from simultaneous MRE and tACS elicited elastic waves of negligible amplitude compared with the extrinsic actuation levels reported in the literature, which allowed accurate reconstructions of the complex shear modulus. Qualitative electrical conductivity maps retrieved by MREIT accurately delineated anatomical regions of the brain model and could be used to recover reasonably accurate distributions of tACS-induced currents. This multi-physics approach has potential for translation to human brain imaging, and may provide more possibilities for the characterization of brain function together than in isolation. [ABSTRACT FROM AUTHOR]

Background: Non-alcoholic fatty liver disease (NAFLD) incidence is rapidly increasing. Objective: Our study aimed to assess diabetic and non-diabetic NAFLD using non-invasive imaging tools; conventional US, Chemical shift MRI, and MRE to evaluate the degree of liver steatosis and fibrosis. Patients and methods: In this case-control study, a total of 130 subjects including 90 NAFLD patients {50 diabetic (Group I) & 40 non-diabetic (Group II), as well as 40 controls (Group III) }, were enrolled. The mean age in the present study was 51.46 ± 7.54 years in group I, 48.40 ± 7.47 years in group II, and 49.55 ± 7.95 years in group III (controls). Most of our subjects were females (78%, 77.5%, and 65% in groups I, II, and III respectively). Assessment of liver steatosis was done using conventional US and chemical shift (in-phase and out-of-phase) MR imaging. Assessment of liver stiffness to detect the degree of fibrosis/cirrhosis was done using magnetic resonance enterography (MRE). Results: Diabetic NAFLD patients (group I) had a higher degree of liver steatosis (scores 2 and 3), measured by conventional US, compared to group II (non-diabetic NAFLD). Group I patients had a significantly higher degree of liver steatosis (p = 0.007), measured by chemical shift (in-phase and out-phase) MRI, compared to group II. Liver stiffness measurement by MRE was significantly higher (p = 0.038) in group I (Mean 2.88 ± 0.81 kPa) than in group II (mean 2.46 ± 0.71kPa). Liver fibrosis (≥ F2) was significantly higher (p = 0.021) in group 1 (20 of 50 patients (40%)) than in group II (7 of 40 patients (17.5%)). Conclusions: Current non-invasive imaging methods demonstrated their value as non-invasive imaging biomarkers to evaluate the degree of liver steatosis in NAFLD and its progression into fibrosis/cirrhosis. [ABSTRACT FROM AUTHOR]

French bean is (Phaseolus vulgaris) widely grown legume worldwide and is the most important pulse crop in the Indian subcontinent. The productivity is adversely affected by a large number of biotic and abiotic stresses. Micro RNAs (miRNAs) have been implicated in the regulation of plant responses to several biotic and abiotic stresses. Boron (B) toxicity is a significant limitation to cereal crop production worldwide. In this study, RT-qPCR confirmed seven miRNAs were responsive to boron toxicity. The known predicted targets and their functional analysis revealed that most of the targets represent transcription factors. GO results supported our hypothesis that miRNAs were found to be involved in diverse cellular processes, including plant circadian cycle, vegetative development, transcription, and cross adaptation. The results obtained would provide new insights to the complex regulatory mechanism employing small non-coding regulatory RNAs toward stress adaptation.

A retrospective analysis was conducted to investigate how a bright luminal sign on high b-value diffusion-weighted imaging (DWI) could be considered as a new biomarker for identifying fibrotic strictures in Crohn’s disease (CD). Fibrotic strictures, due to excessive deposition of extracellular matrix following chronic inflammatory processes, can be difficult to distinguish from inflammatory strictures using endoscopy. This study was performed on 65 patients with CD who underwent MRE, and among them 32 patients showed the bright luminal sign on high b-value DWI. DWI findings were compared to pre- and post-contrast MRE data. Luminal bright sign performance results were calculated using a confusion matrix, the relationship between categorical variables was assessed by the χ2 test of independence, and the Kruskal–Wallis test (ANOVA) was used for the assessment of statistical significance of differences between groups. The results indicated a high sensitivity (90%) and specificity (85%) of the bright luminal sign for fibro-stenotic CD and a significant correlation between DWI luminal brightness and markers such as the homogeneous enhancement pattern (p < 0.001), increase in enhancement percentage from 70 s to 7 min after gadolinium injection (p < 0.001), and submucosal fat penetration (p = 0.05). These findings indicate that DWI hyperintensity can be considered as a good non-invasive indicator for the detection of severe intestinal fibrosis and may provide an efficient and accurate method for assessing fibrotic strictures. This new non-invasive biomarker could allow an early diagnosis of fibrotic stricture, delaying the onset of complications and subsequent surgery. Moreover, further evaluations through larger prospective trials with histopathological correlation are needed to confirm these results and completely determine the clinical benefits of DWI in treating CD.

Nonalcoholic fatty liver disease (NAFLD) is rapidly becoming one of the most common causes of liver disease. The progressive subtype of NAFLD, nonalcoholic steatohepatitis (NASH), leads to cirrhosis, hepatocellular carcinoma, and mortality. Fibrosis is the strongest predictor for complications. Due to the invasive nature of liver biopsy, noninvasive testing methods have emerged to detect fibrosis and predict outcomes. Of these modalities, magnetic resonance elastography (MRE) has demonstrated the highest accuracy to detect fibrosis. In this review, we will focus on the emerging data regarding MRE and liver fibrosis, cirrhosis, and portal hypertension in NAFLD.

Introduction: Recent investigations into the biomechanics of the brain have unveiled alteration in tissue stiffness triggered by external stimuli. For instance, visual stimulation effects can be measured in elasticity images of the cortex generated by functional magnetic resonance elastography (MRE). Such a mechanical characterization method combined with non-invasive brain stimulation (NIBS), a technique that seeks to selectively modulate particular parts of the brain using weak electrical currents, has the potential to influence research on various neurological disorders. In this in silico study, we aimed to elucidate individual and interdependent aspects related to a synchronized biomechanical imaging and non-invasive brain stimulation methodology. Magnetic resonance electrical impedance tomography (MREIT) was incorporated to the pipeline, providing a promising way of evaluating NIBS-induced electrical current patterns in the brain while leveraging MRE and transcranial alternating current stimulation (tACS) experimental settings.Methods: A mouse head model was assembled using open-access atlases to include five anatomical structures: skin/subcutaneous tissue, skull, cerebrospinal fluid (CSF), brain white and grey matters. MRE, tACS, and MREIT experiments were simulated using Comsol Multiphysics with Matlab Livelink. Synthetic MRE and MREIT data were processed using the subzone non-linear inversion and harmonic Bz algorithm, respectively, to reconstruct images of the distributed complex shear modulus and electrical conductivity.Results and Discussion: Lorentz body forces arising from simultaneous MRE and tACS elicited elastic waves of negligible amplitude compared with the extrinsic actuation levels reported in the literature, which allowed accurate reconstructions of the complex shear modulus. Qualitative electrical conductivity maps retrieved by MREIT accurately delineated anatomical regions of the brain model and could be used to recover reasonably accurate distributions of tACS-induced currents. This multi-physics approach has potential for translation to human brain imaging, and may provide more possibilities for the characterization of brain function together than in isolation.

Introduction: Magnetic resonance elastography (MRE) is a non-invasive method to quantify biomechanical properties of human tissues. It has potential in diagnosis and monitoring of kidney disease, if established in clinical practice. The interplay of flow and volume changes in renal vessels, tubule, urinary collection system and interstitium is complex, but physiological ranges of in vivo viscoelastic properties during fasting and hydration have never been investigated in all gross anatomical segments simultaneously. Method: Ten healthy volunteers underwent two imaging sessions, one following a 12-hour fasting period and the second after a drinking challenge of >10 mL per kg body weight (60--75 min before the second examination). High-resolution renal MRE was performed using a novel driver with rotating eccentric mass placed at the posterior-lateral wall to couple waves (50 Hz) to the kidney. The biomechanical parameters, shear wave speed (cs in m/s), storage modulus (Gd in kPa), loss modulus (Gl in kPa), phase angle 2 π atan Gl Gd and attenuation (α in 1/mm) were derived. Accurate separation of gross anatomical segments was applied in post-processing (whole kidney, cortex, medulla, sinus, vessel). Results: High-quality shear waves coupled into all gross anatomical segments of the kidney (mean shear wave displacement: 163 ± 47 μm, mean contamination of second upper harmonics <23%, curl/divergence: 4.3 ± 0.8). Regardless of the hydration state, median Gd of the cortex and medulla (0.68 ± 0.11 kPa) was significantly higher than that of the sinus and vessels (0.48 ± 0.06 kPa), and consistently, significant differences were found in cs,, and Gl (all p < 0.001). The viscoelastic parameters of cortex and medulla were not significantly different. After hydration sinus exhibited a small but significant reduction in median Gd by 0.02 ± 0.04 kPa (p = 0.01), and, consequently, the cortico-sinusoidaldifference in Gd increased by 0.04 ± 0.07 kPa (p = 0.05). Only upon hydration, the attenuation in vessels became lower (0.084 ± 0.013 1/mm) and differed significantly from the whole kidney (0.095 ± 0.007 1/mm, p = 0.01). Conclusion: High-resolution renal MRE with an innovative driver and well-defined 3D segmentation can resolve all renal segments, especially when including the sinus in the analysis. Even after a prolonged hydration period the approach is sensitive to small hydration-related changes in the sinus and in the corticosinusoidal- difference. [ABSTRACT FROM AUTHOR]

In the face of escalating credit card fraud due to the surge in e-commerce activities, effectively distinguishing between legitimate and fraudulent transactions has become increasingly challenging. To address this, various machine learning (ML) techniques have been employed to safeguard cardholders and financial institutions. This article explores the use of the Ensemble Hidden Markov Model (EHMM) combined with two distinct feature extraction methods: principal component analysis (PCA) and a proposed statistical feature set termed MRE, comprising Mean, Relative Amplitude, and Entropy. Both the PCA-EHMM and MRE-EHMM approaches were evaluated using a dataset of European cardholders and demonstrated comparable performance in terms of recall (sensitivity), specificity, precision, and F1-score. Notably, the MRE-EHMM method exhibited significantly reduced computational complexity, making it more suitable for real-time credit card fraud detection. Results also demonstrated that the PCA and MRE approaches perform significantly better when integrated with the EHMM in contrast to the conventional HMM approach. In addition, the proposed MRE-EHMM and PCA-EHMM techniques outperform other classic ML models, including random forest (RF), linear regression (LR), decision trees (DT) and K-nearest neighbour (KNN).

Introduction: Magnetic resonance elastography (MRE) is a non-invasive method to quantify biomechanical properties of human tissues. It has potential in diagnosis and monitoring of kidney disease, if established in clinical practice. The interplay of flow and volume changes in renal vessels, tubule, urinary collection system and interstitium is complex, but physiological ranges of in vivo viscoelastic properties during fasting and hydration have never been investigated in all gross anatomical segments simultaneously.Method: Ten healthy volunteers underwent two imaging sessions, one following a 12-hour fasting period and the second after a drinking challenge of >10 mL per kg body weight (60–75 min before the second examination). High-resolution renal MRE was performed using a novel driver with rotating eccentric mass placed at the posterior-lateral wall to couple waves (50 Hz) to the kidney. The biomechanical parameters, shear wave speed (cs in m/s), storage modulus (Gd in kPa), loss modulus (Gl in kPa), phase angle (Υ=2πatanGlGd) and attenuation (α in 1/mm) were derived. Accurate separation of gross anatomical segments was applied in post-processing (whole kidney, cortex, medulla, sinus, vessel).Results: High-quality shear waves coupled into all gross anatomical segments of the kidney (mean shear wave displacement: 163 ± 47 μm, mean contamination of second upper harmonics

Studies of pre-bomb mollusks live-collected around the Australian coastline have concluded that near-shore marine radiocarbon reservoir effects are small and relatively uniform. These studies are based on limited samples of sometimes dubious quality representing only selective parts of Australia's lengthy coastline. We systematically examine spatial variability in the marine radiocarbon reservoir effect (ΔR) through analysis of 292 live-collected mollusk samples across the Australian mainland coasts and near-shore islands subject to strict selection criteria. This study presents 233 new ΔR values combined with an evaluation of 59 previously published values. Results demonstrate significant spatial variability in marine radiocarbon reservoir effects across the study region. ΔR values range from 68 ± 24 14C years off the Pilbara region of Western Australia to –337 ± 46 14C years in the southern Gulf of Carpentaria in Queensland. Most sets of local values exhibit internal consistency, reflecting the dominant influence of regional oceanography, including depletion in ΔR values southwards along the eastern Australian coastline coincident with the East Australian Current. Anomalous values are attributed to inaccurate documentation, species-specific relationships with the carbon cycle and/or short-term fluctuations in marine radiocarbon activities. To account for the heterogeneous distribution of marine 14C, we recommend using a location specific ΔR value calculated using the Australian ΔR Calculator, available at: https://delta-r-calc.jcu.io/. [ABSTRACT FROM AUTHOR]

Nonlinearity is a common source of signal and channel distortion in digital communication. In many circumstances, such distortions must be compensated by equalization algorithms or devices. This paper presents a semi-blind equalization method for nonlinear multichannel signal recovery in convolutive mixtures. The proposed work takes into account quadratic nonlinearities and applies the mutually referenced equalization (MRE) approach to estimate the equalizer as well as estimate the transmitted signal from the nonlinear convolutive mixture. The proposed semi-blind model combines both data and pilots in addition to the MRE technique to develop a cost function that provides an equalization solution. The proposed technique has various advantages, including robustness to channel order misspecification, implementational simplicity, and provides a single solution for several equalization delays. The simulation results show that the proposed technique has intriguing performance features with robustness to low SNR.

Objective: This study sought to determine the diagnostic performance of magnetic resonance elastography (MRE) for pancreatic solid masses, compared with diffusion-weighted imaging (DWI) and serum CA19-9, to establish a threshold for differentiating between pancreatic ductal adenocarcinoma (PDAC) and benign tumors in pancreas. Materials and methods: Between July 2021 to January 2023, 75 adult patients confirmed with pancreatic solid tumors were enrolled in this prospective and consecutive study. All patients underwent MRE and DWI examinations that were both performed with a spin echo-EPI sequence. Stiffness maps and apparent diffusion coefficient (ADC) maps were generated, with MRE-derived mass stiffness and stiffness ratio (computing as the ratio of mass stiffness to the parenchyma stiffness) and DWI-derived ADC values obtained by placing regions of interest over the focal tumors on stiffness and ADC maps. Further analysis of comparing diagnostic performances was assessed by calculating the area under ROC curves. Results: PDAC had significantly higher tumor stiffness [3.795 (2.879–4.438) kPa vs. 2.359 (2.01–3.507) kPa, P = 0.0003], stiffness ratio [1.939 (1.562–2.511) vs. 1.187 (1.031–1.453), P < 0.0001] and serum CA19-9 level [276 (31.73–1055) vs. 10.45 (7.825–14.15), P < 0.0001] than other pancreatic masses. Mass stiffness, stiffness ratio and serum CA19-9 showed good diagnostic performance for differentiation with AUC of 0.7895, 0.8392 and 0.9136 respectively. The sensitivity/specificity/positive predictive value/negative predictive value for differentiating malignant from benign pancreatic tumors with mass stiffness (cutoff, > 2.8211 kPa) and stiffness ratio (cutoff, > 1.5117) were 78.4/66.7/82.9/60% and 77.8/83.3/90.3/65.2% respectively. The combined performance of Mass stiffness, stiffness ratio and serum CA19-9 got an AUC of 0.9758. Conclusion: MRE holds excellent clinical potential in discriminating pancreatic ductal adenocarcinoma from other pancreatic solid masses according to their mechanical properties. [ABSTRACT FROM AUTHOR]

Background and Aim: Recently, pemafibrate and a low‐carbohydrate diet (LCD) have each been reported to improve fatty liver disease. However, it is unclear whether their combination improves fatty liver disease and is equally effective in obese and non‐obese patients. Methods: In 38 metabolic‐associated fatty liver disease (MAFLD) patients, classified by baseline body mass index (BMI), changes in laboratory values, magnetic resonance elastography (MRE), and magnetic resonance imaging‐proton density fat fraction (MRI‐PDFF) were studied after 1 year of combined pemafibrate plus mild LCD. Results: The combination treatment resulted in weight loss (P = 0.002), improvement in hepatobiliary enzymes (γ‐glutamyl transferase, P = 0.027; aspartate aminotransferase, P < 0.001; alanine transaminase [ALT], P < 0.001), and improvement in liver fibrosis markers (FIB‐4 index, P = 0.032; 7 s domain of type IV collagen, P = 0.002; M2BPGi, P < 0.001). Vibration‐controlled transient elastography improved from 8.8 to 6.9 kPa (P < 0.001) and MRE improved from 3.1 to 2.8 kPa (P = 0.017) in the liver stiffness. MRI‐PDFF improved from 16.6% to 12.3% in liver steatosis (P = 0.007). In patients with a BMI of 25 or higher, improvements of ALT (r = 0.659, P < 0.001) and MRI‐PDFF (r = 0.784, P < 0.001) were significantly correlated with weight loss. However, in patients with a BMI below 25, the improvements of ALT or PDFF were not accompanied by weight loss. Conclusions: Combined treatment with pemafibrate and a low‐carbohydrate diet resulted in weight loss and improvements in ALT, MRE, and MRI‐PDFF in MAFLD patients. Although such improvements were associated with weight loss in obese patients, the improvements were observed irrespective of weight loss in non‐obese patients, indicating this combination can be effective both in obese and non‐obese MAFLD patients. [ABSTRACT FROM AUTHOR]

INTRODUCTION: Leucine-rich alpha-2 glycoprotein (LRG) is a newly studied biomarker for inflammatory diseases. This study aimed to investigate whether LRG can be used for evaluating transmural activity in patients with Crohn’s disease (CD). METHODS: We performed magnetic resonance enterography (MRE) in 227 consecutive patients with CD from June 2020 to August 2021. We prospectively compared MRE findings with clinical and laboratory data including LRG. MRE was evaluated using 2 validated scoring systems, and transmural inflammation was defined as having a maximum simplified magnetic resonance index of activity (sMaRIA) score of ‡4 and a 5-point classification score of ‡9, respectively.RESULTS: The correlation between LRG and the total MRE score showed a positive correlation (r 5 0.576 for the sMaRIA score, P < 0.01, and r 5 0.633 for the 5-point score, P < 0.01). Serum concentrations of LRG significantly increased as MRE scores increased (P < 0.01). The area under the curve of LRG for a sMaRIA score of ‡4 and a 5-point score of ‡9 was 0.845 and 0.869, respectively, which was significantly higher than that of CDAI (P < 0.01) or C-reactive protein (P < 0.01). LRG levels of ‡14 mg/mL had a 67% sensitivity and 90% specificity for a sMaRIA score of ‡4 and a 73% sensitivity and 89% specificity for a 5-point score of ‡9. Patients with high LRG levels were also strongly associated with CD-related hospitalization, surgery, and clinical relapse compared with those with low LRG levels (P < 0.01 for all). DISCUSSION: LRG is a highly accurate serum biomarker for detecting transmural activity in patients with CD. Results need to be validated in further multicenter studies. [ABSTRACT FROM AUTHOR]

Background The Lémann Index [LI] and the recently updated LI are tools for measuring structural bowel damage in adults with Crohn's disease [CD] but have not been evaluated in children. We aimed to validate the updated LI in the prospective multicentre ImageKids study of paediatric CD. Methods We included children with CD undergoing magnetic resonance enterography [MRE], pelvic magnetic resonance imaging [MRI] and ileocolonoscopy. Half were followed for 18 months, when MRE was repeated. Serum was collected for fibrosis-related proteomic markers. The LI was calculated by central readers from the MRE, ileocolonoscopy, physical examination and surgical data. Reliability and construct validity were assessed at baseline, while responsiveness and test–retest reliability were explored longitudinally. Results In total, 240 children were included (mean age, 14.2 ± 2.5 years; median disease duration, 2.2 years [interquartile range, IQR 0.25–4.42]; median baseline LI, 4.23 [IQR 2.0–8.8]). The updated LI had excellent inter-observer reliability (interclass correlation coefficient [ICC] = 0.94, 95% confidence interval [CI] 0.92–0.95) but poor, although statistically significant, correlation with radiologist and gastroenterologist global assessments of damage and with serum proteomic levels of fibrotic markers [ rho = 0.15–0.30, most p < 0.05]. The updated LI had low discriminative validity for detecting damage (area under the receiver operating characteristic curve [AUC-ROC] 0.69, 95% CI 0.62–0.75). In 116 repeated MREs, responsiveness was suboptimal for differentiating improved from unchanged disease [AUC-ROC 0.58, 95% CI 0.45–0.71]. Test–retest reliability was high among stable patients [ICC = 0.84, 95% CI 0.72–0.91]. Conclusion Overall, the updated LI had insufficient psychometric performance for recommending its use in children. An age-specific index may be needed for children with shorter disease duration than typical adult cohorts. [ABSTRACT FROM AUTHOR]

Background The importance and pathophysiology of transmural healing in patients with Crohn's disease [CD] remains to be verified. We aimed to examine the association between serum concentrations of biologics and transmural remission evaluated via magnetic resonance enterography [MRE]. Methods We enrolled patients with CD who received maintenance biologics 1 year after induction and prospectively followed up for at least 1 year after baseline laboratory, endoscopic and MRE examination. We evaluated the relationship between baseline factors including the presence of transmural remission and patient prognosis, as well as between serum concentrations and transmural remission. Results We included 134 patients, of whom 65, 31, 27 and 11 received infliximab, adalimumab, ustekinumab and vedolizumab, respectively. Those who achieved transmural remission showed a lower risk of hospitalization and surgery than those who did not achieve remission [ p  < 0.01]. Adjusted hazard ratios of transmural remission for predicting hospitalization and surgery were 0.11 and 0.02, respectively, which were lower than those of clinical remission, biochemical remission and endoscopic remission. Regarding serum concentrations, the median concentration was higher in patients with transmural remission than in patients with transmural activity for all agents [ p  < 0.01 for infliximab, p  = 0.04 for adalimumab, p  < 0.01 for ustekinumab, p  = 0.08 for vedolizumab]. Conclusions Transmural remission was the best predictor for prognosis in CD patients who received maintenance biologic therapy. High drug concentration levels were associated with transmural remission confirmed via MRE. [ABSTRACT FROM AUTHOR]

MicroRNAs (miRNAs or miRs) are small noncoding RNAs derived from genome to control target gene expression. Recently we have developed a novel platform permitting high-yield production of bioengineered miRNA agents (BERA). This study is to produce and utilize novel fully-humanized BERA/miR-328-3p molecule (hBERA/miR-328) to delineate the role of miR-328-3p in controlling nutrient uptake essential for cell metabolism. We first demonstrated successful high-level expression of hBERA/miR-328 in bacteria and purification to high degree of homogeneity (>98%). Biologic miR-328-3p prodrug was selectively processed to miR-328-3p to suppress the growth of highly-proliferative human osteosarcoma (OS) cells. Besides glucose transporter protein type 1, gene symbol solute carrier family 2 member 1 (GLUT1/SLC2A1), we identified and verified large neutral amino acid transporter 1, gene symbol solute carrier family 7 member 5 (LAT1/SLC7A5) as a direct target for miR-328-3p. While reduction of LAT1 protein levels by miR-328-3p did not alter homeostasis of amino acids within OS cells, suppression of GLUT1 led to a significantly lower glucose uptake and decline in intracellular levels of glucose and glycolytic metabolite lactate. Moreover, combination treatment with hBERA/miR-328 and cisplatin or doxorubicin exerted a strong synergism in the inhibition of OS cell proliferation. These findings support the utility of novel bioengineered RNA molecules and establish an important role of miR-328-3p in the control of nutrient transport and homeostasis behind cancer metabolism.

Nonalcoholic fatty liver disease (NAFLD) is estimated to afflict approximately 1 billion individuals worldwide. In a subset of NAFLD patients, who have the progressive form of NAFLD termed nonalcoholic steatohepatitis (NASH), it can progress to advanced fibrosis, cirrhosis, hepatocellular carcinoma, and liver-related morbidity and mortality. NASH is typically characterized by a specific pattern on liver histology, including steatosis, lobular inflammation, and ballooning with or without peri-sinusoidal fibrosis. Thus, key issues in NAFLD patients are the differentiation of NASH from simple steatosis and identification of advanced hepatic fibrosis. Until now, liver biopsy has been the gold standard for identifying these 2 critical end points, but has well-known limitations, including invasiveness; rare but potentially life-threatening complications; poor acceptability; sampling variability; and cost. Furthermore, due to the epidemic proportion of individuals with NAFLD worldwide, liver biopsy evaluation is impractical, and noninvasive assessment for the diagnosis of NASH and fibrosis is needed. Although much of the work remains to be done in establishing cost-effective strategies for screening for NASH, advanced fibrosis, and cirrhosis, in this review, we summarize the current state of the noninvasive assessment of liver disease in NAFLD, and we provide an expert synthesis of how these noninvasive tools could be utilized in clinical practice. Finally, we also list the key areas of research priorities in this area to move forward clinical practice.

This paper is dedicated to examine the size-dependent nonlinear forced dynamics of MRE-cored sandwich micro-pipes in existence of external distributed load and internal flow. For this aim, Euler-Bernoulli beam theory, considering von-Karman nonlinearity, together with the modified couple stress theory (MCST) are exploited to attain a mathematical formulation of the problem. Employing Galerkin's approach with consideration of two axial and transverse modes, the obtained nonlinear partial differential equations are discretized, from which nonlinear ordinary equations are achieved. Thereafter, static condensation method is utilized in order to reduce the number of the obtained ordinary equations. The acquired nonlinear equations are then solved according to the method of multiple scales, which leads to nonlinear natural frequencies and frequency-response curves of the system. Throughout the numerical analysis, the effect of a smart MRE core existence on the system's response, considering various boundary conditions, is explored. Additionally, a numerical investigation is implemented to highlight the influences of MRE-related intrinsic properties namely the intensity of the applied magnetic potential and MRE core thickness on the natural frequencies, frequency-response and load-response curves of the system. Totally, the substantial role of the MRE core and its intrinsic characteristics on the dynamic response of the system is explored, which implies that, this smart core could be a good candidate in such sandwich structures in order to control and boost the dynamic properties and response of the mechanical systems. [ABSTRACT FROM AUTHOR]

Background: MR enterography (MRE) has been increased in the last decade as a modality of choice in diagnosis and evaluation of small bowel diseases in both children and adults. Lacking ionizing radiation, non-invasiveness, excellent soft tissue resolution, adequate luminal distension of small bowel loops are the advantages of this technique. Acquisition of images was used to be: T2WI, steady-state free precession, and T1WI, fat-suppressed gadolinium contrast-enhanced sequences. Multipoint Dixon sequence was added recently to the routine MR enterography protocol. The current study aimed to evaluate the added value of multipoint Dixon sequence as a valuable modification of MR enterography protocol for better assessment of small bowel lesions as activity of Crohn's disease, small bowel polyps, fibrotic strictures, with modification of MRE protocol in the future with less time consumption and better radiological evaluation. Methods: The current research was a prospective cross-sectional study. Data were collected prospectively after getting ethical approval from the ethical committee of the faculty of medicine, in our university. Study population: The sample size was 69 adult patients with suspected small bowel lesions, within the period from January 2022 to 30th December 2022. Written informed consent was obtained from all studied cases before the study, who were enrolled in this study. This number was calculated by using MedCalc 19 program by setting alpha error significance of 0.05%, 95% confidence level, and 80% power sample. Results: This study enrolled 69 patients with recurrent abdominal pain and/or bleeding in stool. The patients' age ranged from 18 to 50 years, with a mean of 32.6 ± 8.8. There is slightly higher female prevalence. The most common positive imaging findings in the studied patients were mucosal thickening in terms of submucosal fat deposition (36.23% of the MRE examination and 39.13% of the MRE with added Dixon sequence). Adding Dixon sequence yielded significantly higher AUC (97.2% vs. 90.5%, p = 0.047), higher sensitivity (100% vs. 92.16%), specificity (94.4% vs. 88.89%), accuracy (98.55% vs. 91.3%), positive predictive value (98.08% vs. 95.92%), and negative predictive value (100% vs. 80%). Conclusions: MRE is an excellent imaging modality in the assessment of small bowel diseases without the use of ionizing radiation. Developing MR-based sequences as multi-point Dixon sequence have the potential to improve the ability of MRE to image the subtle changes as Crohn's accompanying early inflammatory changes and fibrosis, as well as small intestinal polyps. Familiarity with MR enterography is essential for radiologists and gastroenterologists who participate in the clinical management of small intestinal diseases. [ABSTRACT FROM AUTHOR]

In this paper, we propose a flap valve micro-fluidic pump that relies on an electromagnetic actuation mechanism. We employed a multiphysics-based simulation methodology to prove the proposed concept. More specifically, the complex and fully coupled magneto-solid-fluid interaction analyses were carried out via a two-dimensional, time-dependent computational model to determine the deformation of the upper wall of the pump chamber and the velocity field inside the pump channel. The simulations were performed in COMSOL Multiphysics software. The simulation approach was verified through a validity check study by replicating an existing study in the literature. Once verified, the full simulations were performed for the proposed concept. The performance characteristics of the pump were presented and discussed. In addition, a parametric study was conducted to see the effects of important design parameters on the net pumped volume, results of which were also presented and discussed. The proposed micropump can transfer 1.9 µL of fluid in one pumping cycle, which is almost two times the other micropump models. Also, the proposed flap valve can reduce the backflow up to 10 times during the expansion phase in comparison with the no valve model. The parametric studies demonstrated that the net pumped volume of the fluid is directly proportional to the channel height and valve spacing distance and is inversely proportional to the upper wall thickness, elastic modulus of the pump structure, width, height, and Poisson ratio of the valves. The proposed micropump could potentially be used in a broad range of applications, such as an insulin dosing system for Type 1 Diabetic patients, artificial organs to transport blood, organ-on-chip applications, and so on. [ABSTRACT FROM AUTHOR]

Hepatocellular carcinoma (HCC) is the most common primary liver cancer and a major public health problem worldwide. Liver fibrosis is closely correlated with liver functional reserve and the risk of HCC development. Meanwhile, malignant tumors generally have high cellularity compared to benign tumors, which results in increased stiffness. Magnetic resonance elastography (MRE) has emerged as a new non-invasive technique for assessing tissue stiffness with excellent diagnostic accuracy, not only for assessing liver fibrosis but also for measuring tumor stiffness. Recent studies provide new evidence that MRE may play an important role in the management of patients with HCC and show several novel clinical applications, such as predicting the development of HCC, differentiating between benign/malignant liver lesions (FLL) and HCC pathological grades, assessing treatment response, and predicting recurrence after treatment, although some findings are controversial. Therefore, we conducted this review to summarize these novel applications of MRE in HCC patients and also discuss their limitations and future advancement. [ABSTRACT FROM AUTHOR]

Objective: To study the feasibility of magnetic resonance elastography (MRE) for the evaluation of myoma uteri in Thai patients. Materials and Methods: A prospective descriptive study was conducted between September 2020 and October 2021. Twenty-six myoma uteri patients were performed in a 3.0-Tesla MRI scanner, added with a pneumatic system generating mechanical waves. For the MRE assessment, the number of acquired slices, mean stiffness with standard deviation (SD), minimum, and maximum stiffnesses (kPa) were recorded. Results: The mean stiffness of the myoma uteri was 3.02 kPa (range 1.83 to 5.06, SD 0.79). Their volume ranged from 56.24 to 716.35 cm? (mean 237.74, SD 187.63. The proportion of lesions ranged from 31.87% to 74.36% of the whole uterus (mean 44.94, SD 16.98). Conclusion: Uterine MRE is a feasible diagnostic tool for studying the tissue stiffness of the myoma uteri, which is higher than normal uterine tissue. The mean stiffness of Thai patient myoma uteri was lower than other ethnicities. [ABSTRACT FROM AUTHOR]

An ISMRM workshop on MR elastography was held at Charité–Universitätsmedizin Berlin on August 25–26, 2022. As an exclusively in‐person event, 65 participants from 9 countries attended the workshop despite COVID‐19–related restrictions. The topics of the workshop covered cellular and microtissue mechanical interactions, the development of MR elastography driver technology, approaches to inverse problems, clinical applications, and integration of MR elastography into multiparametric MRI protocols. The workshop was a great success by promoting direct knowledge exchange as well as for strategizing future directions for MR elastography. In this symposium review, we briefly summarized all oral presentations as well as the concluding panel discussion. [ABSTRACT FROM AUTHOR]

Lingjie Wang,&ast; Jun Ke,&ast; Xiaoyin Hu, Mo Zhu, Yixing Yu Department of Radiology, The First Affiliated Hospital of Soochow University, Soochow, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Mo Zhu; Yixing Yu, Department of Radiology, The First Affiliated Hospital of Soochow University, No. 188 Shizi Road, Soochow, 215000, People’s Republic of China, Tel +86-512-67973009, Fax +86-512-67973061, Email zhumo001@126.com; yuyixing@163.comPurpose: Lacunar infarction is usually diagnosed by conventional technologies, such as CT and diffusion weighted imaging (DWI). To improve the accuracy of diagnosis, neurocognitive screening is still needed. Therefore, additional imaging methods that can assist and provide more accurate and rapid diagnostics are urgently needed. As an initial step towards potentially using MR elastography (MRE) for such diagnostic purposes, we tested the hypothesis that the mechanical properties of tissue in the vicinity of cerebral vasculature change following lacunar infarction in a way that can be quantified using MRE.Patients and Methods: MRE and MR angiography (MRA) images from 51 patients diagnosed with lacunar infarction and 54 healthy volunteers were acquired on a 3T scanner. All diagnoses were confirmed by matching neurocognitive test results to locations of flow obstruction in MRA. ROIs of the cerebral vessels segmented on the MRA images were mapped to the MRE images. Interpolation-based inversion was applied to estimate the regional biomechanical properties of ROIs that included cerebral vessels. The effects of lacunar infarction, sex, and age were analyzed using analysis of covariance (ANOCOVA).Results: Shear moduli over vessel ROIs were significantly lower for the lacunar infarction group than those of the healthy control group. A positive correlation between modulus over vessel ROIs and age was observed. However, no significant correlation was found between sex and the regional biomechanical properties of the vessel ROIs.Conclusion: Results supported the hypothesis and suggest that biomechanical properties may be of utility in diagnosis of lacunar infarction.Keywords: magnetic resonance elastography, MRE, cerebral vasculature, lacunar infarction, biomechanical properties

Hepatocellular carcinoma (HCC) is the most common primary liver cancer and a major public health problem worldwide. Liver fibrosis is closely correlated with liver functional reserve and the risk of HCC development. Meanwhile, malignant tumors generally have high cellularity compared to benign tumors, which results in increased stiffness. Magnetic resonance elastography (MRE) has emerged as a new non-invasive technique for assessing tissue stiffness with excellent diagnostic accuracy, not only for assessing liver fibrosis but also for measuring tumor stiffness. Recent studies provide new evidence that MRE may play an important role in the management of patients with HCC and show several novel clinical applications, such as predicting the development of HCC, differentiating between benign/malignant liver lesions (FLL) and HCC pathological grades, assessing treatment response, and predicting recurrence after treatment, although some findings are controversial. Therefore, we conducted this review to summarize these novel applications of MRE in HCC patients and also discuss their limitations and future advancement.

Escherichia coli is a versatile commensal and pathogenic member of the human microflora. As the primary causative pathogen in urosepsis, E. coli places an immense burden on healthcare systems worldwide. To further exacerbate the issue, multi drug resistance (MDR) has spread rapidly through E. coli populations, making infections more troublesome and costlier to treat. This paper aimed to review the literature concerning the development of MDR in uropathogenic E. coli (UPEC) and explore the existing evidence of current and emerging treatment strategies. While some MDR strains maybe treated with β-lactam-β-lactamase inhibitor combinations as well as cephalosporins, cephamycin, temocillin and fosfomycin, current treatment strategies for many MDR UPEC strains are reliant on carbapenems. Carbapenem overreliance may contribute to the alarming dissemination of carbapenem-resistance amongst some UPEC communities, which has ushered in a new age of difficult to treat infections. Alternative treatment options for carbapenem resistant UPEC may include novel β-lactam-β-lactamase or carbapenemase inhibitor combinations, cefiderocol, polymyxins, tigecycline, aminoglycosides or fosfomycin. For metallo-β-lactamase producing strains (e.g., NDM, IMP-4), combinations of cefazidime-avibacam with aztreonam have been used. Additionally, the emergence of new antimicrobials brings new hope to the treatment of such infections. However, continued research is required to successfully bring these into the clinic for the treatment of MDR E. coli urosepsis. [ABSTRACT FROM AUTHOR]

Psychiatric disorders have a polygenic architecture, often associated with dozens or hundreds of independent genomic loci. Most associated loci impact noncoding regions of the genome, suggesting that the majority of disease heritability originates from the disruption of regulatory sequences. While most research has focused on variants that modify regulatory DNA elements, those affecting cis‐acting RNA sequences, such as miRNA binding sites, are also likely to have a significant impact. We intersected genome‐wide association study (GWAS) summary statistics with the dbMTS database of predictions for miRNA binding site variants (MBSVs). We compared the distributions of MBSV association statistics to non‐MBSVs within brain‐expressed 3′UTR regions. We aggregated GWAS p values at the gene, pathway, and miRNA family levels to investigate cellular functions and miRNA families strongly associated with each trait. We performed these analyses in several psychiatric disorders as well as nonpsychiatric traits for comparison. We observed significant enrichment of MBSVs in schizophrenia, depression, bipolar disorder, and anorexia nervosa, particularly in genes targeted by several miRNA families, including miR‐335‐5p, miR‐21‐5p/590‐5p, miR‐361‐5p, and miR‐557, and a nominally significant association between miR‐323b‐3p MBSVs and schizophrenia risk. We identified evidence for the association between MBSVs in synaptic gene sets in schizophrenia and bipolar disorder. We also observed a significant association of MBSVs in other complex traits including type 2 diabetes. These observations support the role of miRNA in the pathophysiology of psychiatric disorders and suggest that MBSVs are an important class of regulatory variants that have functional implications for many disorders, as well as other complex human traits. [ABSTRACT FROM AUTHOR]

Abstract Background BPH is commonly found in older men which can lead to lower urinary tract symptoms. Magnetic resonance elastography (MRE) is an innovative, noninvasive imaging technique used to evaluate tissue stiffness. There has not been any study, however, that assessed the tissue stiffness in patients with BPH. A prospective descriptive study was performed to demonstrated MRI and MRE techniques of the prostate gland in ten patients with BPH to assess tissue stiffness, features of BPH on MRI and components of BPH in the area of increased stiffness. Results MRI and MRE examinations in all patients were successful without any complications. The mean tissue stiffness of the whole prostate gland was 4.40 ± 0.71 kPa with good reproducibility (ICC 0.82). Stromal components and mixed glandular-stromal components tended to be associated with the areas of increased stiffness on stiffness images, 50.6% for stromal components and 37.9% for mixed glandular-stromal components. Some MRI findings were seen on the patients with high mean stiffness values such as prostatic calcification, type-5 BPH pattern and large prostate volumes. Conclusions Prostate MRE is a useful noninvasive reproducible diagnostic tool for evaluating prostate tissue stiffness by both qualitative and quantitative assessments. The mean prostate tissue stiffness from MRE in patients with BPH in this study was 4.40 ± 0.71 kPa. Some MRI features might be associated with increased tissue stiffness. Trial registration: PID 229. Registered 4 October 2019. http://md.redcap.kku.ac.th