Exploration of influenza A virus PA protein-associated cellular proteins discloses its impact on mitochondrial function.

Influenza A virus can infect respiratory tracts and may cause severe illness in humans. Proteins encoded by influenza A virus can interact with cellular factors and dysregulate host biological processes to support viral replication and cause pathogenicity. The influenza viral PA protein is not only a subunit of influenza viral polymerase but also a virulence factor involved in pathogenicity during infection. To explore the role of the influenza virus PA protein in regulating host biological processes, we performed immunoprecipitation and LC‒MS/MS to globally identify cellular factors that interact with the PA proteins of the influenza A H1N1, 2009 pandemic H1N1, and H3N2 viruses. The results demonstrated that proteins located in the mitochondrion, proteasome, and nucleus are associated with the PA protein. We further discovered that the PA protein is partly located in mitochondria by immunofluorescence and mitochondrial fractionation and that overexpression of the PA protein reduces mitochondrial respiration. In addition, our results revealed the interaction between PA and the mitochondrial matrix protein PYCR2 and the antiviral role of PYCR2 during influenza A virus replication. Moreover, we found that the PA protein could also trigger autophagy and disrupt mitochondrial homeostasis. Overall, our research revealed the impacts of the influenza A virus PA protein on mitochondrial function and autophagy.

Comparative assessment of established and deep learning-based segmentation methods for hippocampal volume estimation in brain magnetic resonance imaging analysis.

In this study, our objective was to assess the performance of two deep learning-based hippocampal segmentation methods, SynthSeg and TigerBx, which are readily available to the public. We contrasted their performance with that of two established techniques, FreeSurfer-Aseg and FSL-FIRST, using three-dimensional T1-weighted MRI scans (n = 1447) procured from public databases. Our evaluation focused on the accuracy and reproducibility of these tools in estimating hippocampal volume. The findings suggest that both SynthSeg and TigerBx are on a par with Aseg and FIRST in terms of segmentation accuracy and reproducibility, but offer a significant advantage in processing speed, generating results in less than 1 min compared with several minutes to hours for the latter tools. In terms of Alzheimer's disease classification based on the hippocampal atrophy rate, SynthSeg and TigerBx exhibited superior performance. In conclusion, we evaluated the capabilities of two deep learning-based segmentation techniques. The results underscore their potential value in clinical and research environments, particularly when investigating neurological conditions associated with hippocampal structures.

Virtual MOLLI Target: Generative Adversarial Networks Toward Improved Motion Correction in MRI Myocardial T1 Mapping.

BACKGROUND: The modified Look-Locker inversion recovery (MOLLI) sequence is commonly used for myocardial T1 mapping. However, it acquires images with different inversion times, which causes difficulty in motion correction for respiratory-induced misregistration to a given target image. HYPOTHESIS: Using a generative adversarial network (GAN) to produce virtual MOLLI images with consistent heart positions can reduce respiratory-induced misregistration of MOLLI datasets. STUDY TYPE: Retrospective. POPULATION: 1071 MOLLI datasets from 392 human participants. FIELD STRENGTH/SEQUENCE: Modified Look-Locker inversion recovery sequence at 3 T. ASSESSMENT: A GAN model with a single inversion time image as input was trained to generate virtual MOLLI target (VMT) images at different inversion times which were subsequently used in an image registration algorithm. Four VMT models were investigated and the best performing model compared with the standard vendor-provided motion correction (MOCO) technique. STATISTICAL TESTS: The effectiveness of the motion correction technique was assessed using the fitting quality index (FQI), mutual information (MI), and Dice coefficients of motion-corrected images, plus subjective quality evaluation of T1 maps by three independent readers using Likert score. Wilcoxon signed-rank test with Bonferroni correction for multiple comparison. Significance levels were defined as P < 0.01 for highly significant differences and P < 0.05 for significant differences. RESULTS: The best performing VMT model with iterative registration demonstrated significantly better performance (FQI 0.88 ± 0.03, MI 1.78 ± 0.20, Dice 0.84 ± 0.23, quality score 2.26 ± 0.95) compared to other approaches, including the vendor-provided MOCO method (FQI 0.86 ± 0.04, MI 1.69 ± 0.25, Dice 0.80 ± 0.27, quality score 2.16 ± 1.01). DATA CONCLUSION: Our GAN model generating VMT images improved motion correction, which may assist reliable T1 mapping in the presence of respiratory motion. Its robust performance, even with considerable respiratory-induced heart displacements, may be beneficial for patients with difficulties in breath-holding. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY: Stage 1.

Comparison of convolutional-neural-networks-based method and LCModel on the quantification of in vivo magnetic resonance spectroscopy.

BACKGROUND: Quantification of metabolites concentrations in institutional unit (IU) is important for inter-subject and long-term comparisons in the applications of magnetic resonance spectroscopy (MRS). Recently, deep learning (DL) algorithms have found a variety of applications on the process of MRS data. A quantification strategy compatible to DL base MRS spectral processing method is, therefore, useful. MATERIALS AND METHODS: This study aims to investigate whether metabolite concentrations quantified using a convolutional neural network (CNN) based method, coupled with a scaling procedure that normalizes spectral signals for CNN input and linear regression, can effectively reflect variations in metabolite concentrations in IU across different brain regions with varying signal-to-noise ratios (SNR) and linewidths (LW). An error index based on standard error (SE) is proposed to indicate the confidence levels associated with metabolite predictions. In vivo MRS spectra were acquired from three brain regions of 43 subjects using a 3T system. RESULTS: The metabolite concentrations in IU of five major metabolites, quantified using CNN and LCModel, exhibit similar ranges with Pearson's correlation coefficients ranging from 0.24 to 0.78. The SE of the metabolites shows a positive correlation with Cramer-Rao lower bound (CRLB) (r=0.46) and  absolute CRLB (r=0.81), calculated by multiplying CRLBs with the quantified metabolite content. CONCLUSION: In conclusion, the CNN based method with the proposed scaling procedures can be employed to quantify in vivo MRS spectra and derive metabolites concentrations in IU. The SE can be used as error index, indicating predicted uncertainties for metabolites and sharing information similar to the absolute CRLB.

A dielectrophoresis-based platform of cancerous cell capture using aptamer-functionalized gold nanoparticles in a microfluidic channel.

In this paper, a microfluidic chip for the manipulation and capture of cancer cells was introduced, in which the combination of dielectrophoresis (DEP) and a binding method based on chemical interactions by using cell-specific aptamers was performed to enhance the capture strength and specificity. The device has been simply constructed from a straight-channel PDMS placed on a glass substrate that has patterned electrode structures and a self-assembled monolayer of gold nanoparticles (AuNPs). The target cells were transported to the manipulation area by flow and attracted down to the region between the electrodes under the influence of positive DEP force. This approach facilitated subsequent selective capture by the modified aptamers on the AuNPs. The distribution of the electric field in the channel has also been simulated to clarify the DEP operation. As a result, the device has been shown to effectively capture target lung cancer cells with a concentration as low as 2 × 10 4 $2\ \ensuremath{\times{}}\ {10}^{4}\ $ cells/mL. The capture specificity in a sample of mixed cells is up to 80.4%. This technique has the potential to be applied to detection methods for many types of cancer.

[Effect of electroacupuncture at different frequencies on brain insulin signaling transduction pathway in Alzheimer's disease mice].

OBJECTIVE: To observe the effect of electroacupuncture (EA) at different frequencies on learning and memory functions, as well as the relevant proteins of brain insulin signal transduction pathway in Alzheimer's disease (AD) mice and explore the effect mechanism of EA in treatment of AD. METHODS: Seventy-two SPF Kunming male mice were randomized into a blank group, a sham-operation group, a model group, a 2 Hz EA group, a 15 Hz EA group and a 30 Hz EA group, 12 mice in each one. In the model group and each EA group, AD model were established by the injection with streptozotocin (ST2) solution (8 mg/kg) into the left lateral ventricles. In the sham-operation group, 0.9% sodium chloride solution of the same volume was injected into the left lateral ventricles. After successful modeling, in each EA group, EA was applied at "Baihui" (GV 20), "Dazhui" (GV 14) and "Shenshu" (BL 23) with corresponding frequencies, once daily. One course of EA intervention consisted of 7 treatments and 2 courses were given totally at interval of 1 day. After modeling and intervention, Morris water maze test was conducted for the mice of each group. Using immunohistochemistry and Western blot method, the protein expression of insulin receptor (IR), insulin receptor substrate-1 (IRS-1) and phosphatidylinositol 3-kinase (PI3K) was detected in the hippocampal of the mice after intervention. RESULTS: Compared with the blank group, in the model group, the 2 Hz, 15 Hz and 30 Hz EA groups, the escape latency and the first time of crossing the platform were all extended (P<0.01), and the number of crossing the platform was reduced (P<0.01) after modeling. When compared with the blank group, the escape latency and the first time of crossing the platform were all extended (P<0.01), and the number of crossing the platform was reduced (P<0.01) in the model group after intervention. In the 2 Hz, 15 Hz and 30 Hz EA groups, the escape latency and the first time of crossing the platform were all shortened (P<0.01), and the number of crossing the platform was increased (P<0.05, P<0.01) after intervention when compared with the model group. The escape latency and the first time of crossing the platform were all shortened (P<0.01, P<0.05), and the number of crossing the platform was increased (P<0.05) in the 15 Hz and 30 Hz EA groups in comparison with the 2 Hz EA group. The protein expression levels of IR, IRS-1 and PI3K were reduced in the model group when compared with those of the blank group (P<0.01, P<0.05); and these protein expression levels were increased in the 15 Hz and 30 Hz EA groups compared with the model group (P<0.05, P<0.01). Compared with the 2 Hz EA group, the protein expression levels of IR, IRS-1 and PI3K were all elevated in the 15 Hz and 30 Hz EA groups (P<0.05). CONCLUSION: The learning and memory function of AD mice may be improved through regulating brain insulin signaling transconduction pathway with electroacupuncture, and electroacupuncture at 15 Hz and 30 Hz obtains the overall better effect compared with the intervention at 2 Hz.

Large-Area Nonfullerene Organic Photovoltaic Modules with a High Certified Power Conversion Efficiency.

Achieving large-area organic photovoltaic (OPV) modules with reasonable cost and performance is an important step toward commercialization. In this work, solution-processed conventional and inverted OPV modules with an area of 216 cm2 were fabricated by the blade coating method. Film uniformity was controlled by adjusting the fabrication parameters of the blade coating procedure. The influence of the concentration of the solutions of the interfacial materials on OPV module performance was investigated. For OPV modules based on the PM6:Y6 photoactive layer, a certificated power conversion efficiency (PCE) of 9.10% was achieved for the conventional OPV modules based on the TASiW-12 interfacial layer while a certificated PCE of 11.27% was achieved for the inverted OPV modules based on the polyethylenimine (PEI) interfacial layer. As for OPV modules based on a commercially available photoactive layer, PV-X Plus, a PCE of 8.52% was achieved in the inverted OPV modules. A halogen-free solvent, o-xylene, was used as the solvent for PV-X Plus, which makes the industrial production much more environmentally friendly.

Effects of reduced gag cleavage efficiency on HIV-1 Gag-Pol package.

BACKGROUND: HIV-1 pol, which encodes enzymes required for virus replication, is initially translated as a Gag-Pol fusion protein. Gag-Pol is incorporated into virions via interactions with Gag precursor Pr55gag. Protease (PR) embedded in Gag-Pol mediates the proteolytic processing of both Pr55gag and Gag-Pol during or soon after virus particle release from cells. Since efficient Gag-Pol viral incorporation depends on interaction with Pr55gag via its N-terminal Gag domain, the prevention of premature Gag cleavage may alleviate Gag-Pol packaging deficiencies associated with cleavage enhancement from PR. RESULTS: We engineered PR cleavage-blocking Gag mutations with the potential to significantly reduce Gag processing efficiency. Such mutations may mitigate the negative effects of enhanced PR activation on virus assembly and Gag-Pol packaging due to an RT dimerization enhancer or leucine zipper dimerization motif. When co-expressed with Pr55gag, we noted that enhanced PR activation resulted in reduced Gag-Pol cis or trans incorporation into Pr55gag particles, regardless of whether or not Gag cleavage sites within Gag-Pol were blocked. CONCLUSIONS: Our data suggest that the amount of HIV-1 Gag-Pol or Pol viral incorporation is largely dependent on virus particle production, and that cleavage blocking in the Gag-Pol N-terminal Gag domain does not exert significant impacts on Pol packaging.

[Curative effect of the combined therapy of warm acupuncture at back-shu points of five zang organs and western medicine on depression of yang deficiency pattern and its attenuating effect].

OBJECTIVE: To compare the therapeutic results and the occurrence of adverse reactions of medicine between the combined therapy of warm acupuncture at back-shu points of five zang organs and the western medicine and the simple wes-tern medication, and observe the therapeutic effect and attenuating effect of this combined therapy in treatment on depression of yang deficiency pattern. METHODS: A total of 80 patients with depression of yang deficiency pattern were randomly divided into an observation group and a control group （39 cases/group）. In the control group, escitalopram oxalate tablets were administered orally every day. In the observation group, on the base of the medication as the control group, warm acupuncture therapy was exerted at back-shu points of five zang organs, for 30 min each time, 5 times a week. The duration of treatment was 6 weeks in two groups. Before and after treatment, the scores of Hamilton depression scale (HAMD) and the antidepressant side effect scale (SERS) were evaluated and electroencephalogram (EEG) was detected; and the curative effect was assessed according to HAMD reduction rate in patients of the two groups. RESULTS: After treatment, the HAMD and SERS scores were lower than those before treatment in both groups. Compared with the control group, the HAMD and SERS scores were lower (P<0.05, P<0.01), and the EEG result was improved (P<0.01) in the observation group. The clinical total effective rate of the observation group was 97.43% (38/39), higher than 92.30% (36/39) of the control group (P<0.05). CONCLUSION: The combined therapy of warm acupuncture at back-shu points of five zang organs and western medicine effectively relieves depression of yang deficiency pattern in the patients and its overall therapeutic effect is better than simple western medication, besides, the combined therapy alleviates the adverse reactions induced by simple western medication.

The Anti-Inflammatory Effect of Hydrogen Gas Inhalation and Its Influence on Laser-Induced Choroidal Neovascularization in a Mouse Model of Neovascular Age-Related Macular Degeneration.

BACKGROUND: Age-related macular degeneration (AMD) is a leading cause of blindness in the elderly. Choroidal neovascularization (CNV) is the major pathologic feature of neovascular AMD. Oxidative damages and the ensuing chronic inflammation are representative of trigger events. Hydrogen gas (H2) has been demonstrated as an antioxidant and plays a role in the regulation of oxidative stress and inflammation. This experiment aimed to investigate the influence of H2 inhalation on a mouse model of CNV. METHODS: Laser was used to induce CNV formation. C57BL/6J mice were divided into five groups: the control group; the laser-only group; and the 2 h, 5 h, and 2.5 h/2.5 h groups that received laser and H2 inhalation (21% oxygen, 42% hydrogen, and 37% nitrogen mixture) for 2 h, 5 h, and 2.5 h twice every day, respectively. RESULTS: The severity of CNV leakage on fluorescence angiography showed a significant decrease in the H2 inhalation groups. The mRNA expression of hypoxia-inducible factor 1 alpha and its immediate downstream target vascular endothelial growth factor (VEGF) showed significant elevation after laser, and this elevation was suppressed in the H2 inhalation groups in an inhalation period length-related manner. The mRNA expression of cytokines, including tumor necrosis factor alpha and interlukin-6, also represented similar results. CONCLUSION: H2 inhalation could alleviate CNV leakage in a laser-induced mouse CNV model, and the potential mechanism might be related to the suppression of the inflammatory process and VEGF-driven CNV formation.

A Pilot Study of Two Different Constraint-Induced Movement Therapy Interventions in Children With Hemiplegic Cerebral Palsy After Botulinum Toxin Injection During Preschool Education.

Introduction: To establish a pilot study on applying two low dose (40 h) constraint-induced movement therapy (CIMT) interventions in children with hemiplegic cerebral palsy (CP) after botulinum toxin (BoNT-A) injection during preschool education. Methods: Five children with spastic CP (mean age: 5.31 years; Gross Motor Function Classification System level I and II) undergoing regular BoNT-A injections and rehabilitation programs were included. Participants were randomly allocated to one of two CIMT programs (40 h): a 2-week 4-hours/day CIMT program and a 4-week 2-hours/day CIMT program. One CIMT program was performed 1 month after a BoNT-A injection, and then the second program was implemented with the next injection. The outcomes were measured by changes in Goal Attainment Scaling (GAS), the grasp and Visual-Motor Integration (VMI) test in Peabody-Developmental Motor Scales (PDMS), the self-care scale on the Functional Skill Scale, and the Caregiver Assistance in Chinese Version of Pediatric Evaluation of Disability Inventory (PEDI-C), Anxiety and Oppositional Defiance Problems of Achenbach System of Empirically-Based Assessment before and after the CIMT interventions, and at every 2 months' follow-up thereafter. Results: The mean age of the participants was 5.31 years, BMI was 16.7 (kg/m2), VIQ was 86.4 ± 8.5, and dose of BoNT-A injection in the upper limb was 42 ± 26.6 units. Grasp, VMI, and self-care on the Functional Skill Scale were significantly better in the 4-week 2-hours/day CIMT program (p < 0.001, p = 0.001, p < 0.001). GAS, grasp, VMI, two 2 self-care scales of PEDI were significantly improved after the CIMT programs, and improvement continued for up to 4 months after the programs. There was no clinical evidence showing changes in the scores for anxiety and oppositional defiance problems during the study period. Conclusions: The preliminary findings, although limited, suggest a potential therapeutic role for the school-based CIMT program after BoNT-A injection. The 4-week 2-hours/day CIMT program might be better than a 2-week 4-hours/day program in terms of self-care and hand function when performed in kindergarten in this pilot study. Furthermore, this pilot study provides valuable information; therefore, it is crucial to include more CP children and blinded assessors for hand function and ADL in the future study.

Brain metabolites in chronic migraine patients with medication overuse headache.

BACKGROUND: Medication overuse headache may be associated with widespread alterations along the thalamocortical pathway, a pathway involved in pain perception and disease progression. This study addressed whether brain metabolites in key regions of the thalamocortical pathway differed between chronic migraine patients with medication overuse headache and without medication overuse headache. METHODS: Magnetic resonance spectroscopic imaging was used to map metabolites in the bilateral anterior cingulate cortices, mid cingulate cortices, posterior cingulate cortices, and the thalami. Sixteen patients with medication overuse headache were compared with 16 matched patients without medication overuse headache and 16 matched healthy controls. RESULTS: Glutamate and glutamine in the right mid cingulate cortex and myo-inositol in the left anterior cingulate cortex were significantly higher in patients with medication overuse headache than patients without medication overuse headache, but similar to healthy controls. Both patient groups exhibited reduced N-acetyl-aspartate and creatine in the thalamus, reduced myo-inositol in the right anterior cingulate cortex, and elevated choline in the right mid cingulate cortex. Finally, a negative association between myo-inositol laterality index in the anterior cingulate cortices and number of days per month with acute medication use was found across all patients. CONCLUSIONS: Patients with medication overuse headache were characterized by a distinct concentration profile of myo-inositol, a glial marker, in the anterior cingulate cortices that may have arisen from medication overuse and could contribute to the development of medication overuse headache.

Considerations of Ultrasound Scanning Approaches in Non-alcoholic Fatty Liver Disease Assessment through Acoustic Structure Quantification.

Non-alcoholic fatty liver disease (NAFLD) is a risk factor for hepatic fibrosis and cirrhosis. Acoustic structure quantification (ASQ), based on statistical analysis of ultrasound echoes, is an emerging technique for hepatic steatosis diagnosis. A standardized measurement protocol for ASQ analysis was suggested previously; however, an optimal ultrasound scanning approach has not been concluded thus far. In this study, the suitability of scanning approaches for the ASQ-based evaluation of hepatic steatosis was investigated. Hepatic fat fractions (HFFs; liver segments VIII, III and VI) of 70 living liver donors were assessed with magnetic resonance spectroscopy. A clinical ultrasound machine equipped with a 3-MHz convex transducer was used to scan each participant using the intercostal, epigastric and subcostal planes to acquire raw data for estimating two ASQ parameters (Cm2 and focal disturbance [FD] ratio) of segments VIII, III and VI, respectively. The parameters were plotted as functions of the HFF for calculating the values of the correlation coefficient (r) and probability value (p). The diagnostic performance of the parameters in discriminating between the normal and steatotic (≥5 and ≥10%) groups was also compared using receiver operating characteristic (ROC) curves. The Cm2 and FD ratio values measured using the epigastric and subcostal planes did not correlate with the severity of hepatic steatosis. However, intercostal imaging exhibited a higher correlation between the ASQ parameters and HFF (r = -0.64, p < 0.001). The diagnostic performance of Cm2 and FD ratio in detecting hepatic steatosis using intercostal imaging was also satisfactory (areas under ROC curves >0.8). Intercostal imaging is an appropriate scanning approach for ASQ analysis of the liver.

Reduction of lipid contamination in MR spectroscopy imaging using signal space projection.

PURPOSE: Lipid contamination can complicate the metabolite quantification in MR spectroscopic imaging (MRSI). In addition to various experimental methods demonstrated to be feasible for lipid suppression, the postprocessing method is beneficial in the flexibility of applications. In this study, the signal space projection (SSP) algorithm is proposed to suppress the lipid signal in the MRSI. METHODS: The performance of lipid suppression using SSP and SSP combined with the Papoulis-Gerchberg (PG) algorithm (PG+SSP) is examined in 2D MRSI data and the results were compared with outer volume saturation (OVS) methods. Up to 10 lipid spatial components were extracted by SSP from lipid signals in the range of 0.8~1.5 ppm. RESULTS: Our results show that most lipid signals were found in the first 4 to 5 components and that lipid signals on the spectra can be suppressed using 4 to 5 components. Metabolites concentrations were quantified using LCModel. Two regions of interest (ROIs) were manually selected on the peripheral and inner brain regions. The quantification of metabolites in terms of fitting reliability (CRLB) and spatial variations within ROIs (SpaVar) is improved using SSP. When 5 to 6 components were used in SSP and PG+SSP, the metabolite concentrations and the associated SpaVar and CRLB are at the same level as those from the OVS. CONCLUSION: We have demonstrated that the SSP method can be used to suppress the lipid signals of MRSI and SSP with 5 to 6 components is suggested to have a similar suppression performance as the OVS method.

Hepatic steatosis assessment using ultrasound homodyned-K parametric imaging: the effects of estimators.

BACKGROUND: The homodyned-K (HK) distribution is an important statistical model for describing ultrasound backscatter envelope statistics. HK parametric imaging has shown potential for characterizing hepatic steatosis. However, the feasibility of HK parametric imaging in assessing human hepatic steatosis in vivo remains unclear. METHODS: In this paper, ultrasound HK µ parametric imaging was proposed for assessing human hepatic steatosis in vivo. Two recent estimators for the HK model, RSK (the level-curve method that uses the signal-to-noise ratio (SNR), skewness, and kurtosis based on the fractional moments of the envelope) and XU (the estimation method based on the first moment of the intensity and two log-moments, namely X- and U-statistics), were investigated. Liver donors (n=72) and patients (n=204) were recruited to evaluate hepatic fat fractions (HFFs) using magnetic resonance spectroscopy and to evaluate the stages of fatty liver disease (normal, mild, moderate, and severe) using liver biopsy with histopathology. Livers were scanned using a 3-MHz ultrasound to construct µ RSK and µ XU images to correlate with HFF analyses and fatty liver stages. The µ RSK and µ XU parametric images were constructed using the sliding window technique with the window side length (WSL) =1-9 pulse lengths (PLs). The diagnostic values of the µ RSK and µ XU parametric imaging methods were evaluated using receiver operating characteristic (ROC) curves. RESULTS: For the 72 participants in Group A, the µ RSK parametric imaging with WSL =2-9 PLs exhibited similar correlation with log10(HFF), and the µ RSK parametric imaging with WSL = 3 PLs had the highest correlation with log10(HFF) (r=0.592); the µ XU parametric imaging with WSL =1-9 PLs exhibited similar correlation with log10(HFF), and the µ XU parametric imaging with WSL =1 PL had the highest correlation with log10(HFF) (r=0.628). For the 204 patients in Group B, the areas under the ROC (AUROCs) obtained using µ RSK for fatty stages ≥ mild (AUROC1), ≥ moderate (AUROC2), and ≥ severe (AUROC3) were (AUROC1, AUROC2, AUROC3) = (0.56, 0.57, 0.53), (0.68, 0.72, 0.75), (0.73, 0.78, 0.80), (0.74, 0.77, 0.79), (0.74, 0.78, 0.79), (0.75, 0.80, 0.82), (0.74, 0.77, 0.83), (0.74, 0.78, 0.84) and (0.73, 0.76, 0.83) for WSL =1, 2, 3, 4, 5, 6, 7, 8 and 9 PLs, respectively. The AUROCs obtained using µ XU for fatty stages ≥ mild, ≥ moderate, and ≥ severe were (AUROC1, AUROC2, AUROC3) = (0.75, 0.83, 0.81), (0.74, 0.80, 0.80), (0.76, 0.82, 0.82), (0.74, 0.80, 0.84), (0.76, 0.80, 0.83), (0.75, 0.80, 0.84), (0.75, 0.79, 0.85), (0.75, 0.80, 0.85) and (0.73, 0.77, 0.83) for WSL = 1, 2, 3, 4, 5, 6, 7, 8 and 9 PLs, respectively. CONCLUSIONS: Both the µ RSK and µ XU parametric images are feasible for evaluating human hepatic steatosis. The WSL exhibits little impact on the diagnosing performance of the µ RSK and µ XU parametric imaging. The µ XU parametric imaging provided improved performance compared to the µ RSK parametric imaging in characterizing human hepatic steatosis in vivo.