Magnetic Resonance Imaging Proton Density Fat Fraction Research Articles

Assessing hepatic steatosis by magnetic resonance in potential living liver donors.

To determine the accuracy of magnetic resonance imaging-proton density fat fraction (MRI-PDFF) measurements for detecting liver fat content in potential living liver donors and to compare these results using liver biopsy findings. A total of 139 living liver donors (men/women: 83/56) who underwent MRI between January 2017 and September 2021 were included in this analysis retrospectively. The PDFFs were measured using both MR spectroscopy (MRS) and chemical shift-based MRI (CS-MRI) for each donor in a blinded manner. Significant positive correlations were found between liver biopsy and MRS-PDFF and CS-MRI PDFF in terms of hepatic steatosis detection [r = 0.701, 95% confidence interval (CI): 0.604-0.798, r = 0.654, 95% CI: 0.544-0.765, P < 0.001, respectively). A weak level correlation was observed between liver biopsy, MRI methods, and vibration-controlled transient elastography attenuation parameters in 42 available donors. Based on receiver operating characteristic (ROC) analysis, MRS-PDFF and CS-MRI PDFF significantly distinguished >5% of histopathologically detected hepatic steatosis with an area under the ROC curve (AUC) of 0.837 ± 0.036 (P < 0.001, 95% CI: 0.766-0.907) and 0.810 ± 0.036 (P < 0.001, 95% CI: 0.739-0.881), respectively. The negative predictive values (NPVs) of MRS-PDFF and CS-MRI PDFF were 88.3% and 81.3%, respectively. In terms of distinguishing between clinically significant hepatic steatosis (≥10% on histopathology), the AUC of MRS-PDFF and CS-MRI were 0.871 ± 0.034 (P < 0.001 95% CI: 0.804-0.937) and 0.855 ± 0.036 (P < 0.001, 95% CI: 0.784-0.925), respectively. The NPVs of MRS-PDFF and CS-MRI were 99% and 92%, respectively. The methods of MRS-PDFF and CS-MRI PDFF provide a non-invasive and accurate approach for assessing hepatic steatosis in potential living liver donor candidates. These MRI PDFF techniques present a promising clinical advantage in the preoperative evaluation of living liver donors by eliminating the requirement for invasive procedures like liver biopsy.

Performance of MAST, FAST, and MEFIB in predicting metabolic dysfunction-associated steatohepatitis.

To identify individuals with metabolic dysfunction-associated steatohepatitis (MASH) or "at-risk" MASH among patients with metabolic dysfunction-associated steatotic liver disease (MASLD), three noninvasive models are available with satisfactory efficiency, which include magnetic resonance imaging [MRI]- AST (MAST), FibroScan-AST (FAST score), and magnetic resonance elastography [MRE] plus FIB-4 (MEFIB). We aimed to evaluate the most accurate approach for diagnosing MASH or "at-risk" MASH. We included 108 biopsy-proven MASLD patients who underwent simultaneous assessment of MRE, MRI proton density fat fraction (MRI-PDFF), and FibroScan scans. Compared with the histological diagnosis, we analyzed the AUC of each model and assessed the accuracy. Our study cohort consisted of 64.8% of MASH and 25.9% of "at-risk" MASH. When analyzing the performance of each model for the diagnostic accuracy of MASH, we found that the AUC [95% CI] of MAST was comparable to FAST (0.803 [0.719-0.886] vs 0.799 [0.707-0.891], P=0.930) and better than MEFIB (0.671 [0.571-0.772], P=0.005). Similar findings were observed in the "at-risk" MASH patients. The AUCs [95% CI] for MAST, FAST, and MEFIB were 0.810 [0.719-0.900], 0.782 [0.689-0.874], and 0.729 [0.619-0.838], respectively. The models of MAST and FAST had comparable AUCs (P=0.347), which were statistically significantly higher than that of MEFIB (P=0.041). Additionally, the cutoffs for diagnosis of MASH were lower than "at-risk" MASH. MAST and FAST performed better than MEFIB in diagnosing "at-risk" MASH and MASH using lower cutoff values. Our findings provided evidence for selecting the most accurate noninvasive model to identify patients with MASH or at-risk MASH.

Velacur ACE outperforms FibroScan CAP for diagnosis of MASLD.

As the prevalence of metabolic dysfunction-associated steatotic liver disease increases, it is imperative to have noninvasive alternatives to liver biopsy. Velacur offers a non-invasive, point-of-care ultrasound-based method for the assessment of liver stiffness and attenuation. The aim of this study was to perform a head-to-head comparison of liver stiffness and liver fat determined by Velacur and FibroScan using MRI-based measurements as the reference standard. This prospective cross-sectional study included 164 adult participants with well-characterized metabolic dysfunction-associated steatotic liver disease. Patients underwent a research exam including Velacur, FibroScan and contemporaneous magnetic resonance elastography, and magnetic resonance imaging proton density fat fraction (MRI-PDFF) scans. The primary outcome was the presence of advanced fibrosis (>F2) as measured by magnetic resonance elastography and the presence of liver fat (>5%) as measured by MRI-PDFF. The mean age and body mass index were 57±12 years and 30.6±4.8kg/m2, respectively. The mean liver stiffness on magnetic resonance elastography was 3.22±1.39kPa and the mean liver fat on MRI-PDFF was 14.2±8%. The liver stiffness assessments by Velacur and FibroScan were similar for the detection of advanced fibrosis (AUC 0.95 vs. 0.97) and were not statistically different (p=0.43). Velacur was significantly better than FibroScan (AUC 0.94 vs. 0.79, p=0.01), for the detection of MRI-PDFF >5% (diagnosis of metabolic dysfunction-associated liver disease). Velacur was superior to FibroScan for liver fat detection with MRI-PDFF as the reference. Velacur and FibroScan were not statistically different for liver stiffness assessment as defined by magnetic resonance elastography.

Evaluation of muscle and bone composition and function in aging women with polycystic ovary syndrome

ObjectiveThe potential effects of polycystic ovary syndrome (PCOS) on the musculoskeletal system are not well established. We examined the musculoskeletal system in women with PCOS in their late reproductive years. Study-designThis cross-sectional study included 34 women with PCOS and 32 control women matched for age and body mass index (BMI). Main outcome measuresDual-energy x-ray absorptiometry (DXA) was used for body composition analysis and cross-sectional areas and fat fraction of muscles were assessed by magnetic resonance imaging-proton density fat fraction (MRI-PDFF) of the abdomen and thigh. Muscle strength was measured using an isokinetic dynamometer. ResultsThe mean age of the PCOS group was 43 ± 3.7 years and of the control group 42.2 ± 3.5 years. Testosterone, free androgen index, and fasting insulin were higher in PCOS patients than controls (p < 0.001, p = 0.001 and p = 0.032, respectively). Patients and controls had similar values for total abdominal muscle area (TAMA), paraspinal muscle area, thigh muscle area, vertebral MRI-PDFF, thigh and paraspinal muscle MRI-PDFF. There was no difference in DXA-derived muscle and bone composition between the two groups. Body composition parameters measured by MRI and DXA were correlated with BMI and fasting insulin levels, but not with androgen levels in both groups. Subgroup analyses showed that PCOS women with obesity had higher TAMA than controls with obesity (p = 0.012). Apart than higher 60°/sec knee extensor average power in nonobese PCOS (p = 0.049), no difference in muscle mechanical function was detected between PCOS patients and controls. ConclusionMusculoskeletal composition and function are similar in PCOS patients and healthy women in late reproductive years. Body composition is linked with obesity and insulin resistance rather than hyperandrogenemia.

IATT liver fat quantification for steatosis grading by referring to MRI proton density fat fraction: a multicenter study.

Several preliminary reports have suggested the utility of ultrasound attenuation coefficient measurements based on B-mode ultrasound, such as iATT, for diagnosing steatotic liver disease. Nonetheless, evidence supporting such utility is lacking. This prospective study aimed to investigate whether iATT is highly concordant with magnetic resonance imaging (MRI)-based proton density fat fraction (MRI-PDFF) and could well distinguish between steatosis grades. A cohort of 846 individuals underwent both iATT and MRI-PDFF assessments. Steatosis grade was defined as grade 0 with MRI-PDFF < 5.2%, grade 1 with 5.2% MRI-PDFF < 11.3%, grade 2 with 11.3% MRI-PDFF < 17.1%, and grade 3 with MRI-PDFF of 17.1%. The reproducibility of iATT and MRI-PDFF was evaluated using the Bland-Altman analysis and intraclass correlation coefficients, whereas the diagnostic performance of each steatosis grade was examined using receiver operating characteristic analysis. The Bland-Altman analysis indicated excellent reproducibility with minimal fixed bias between iATT and MRI-PDFF. The area under the curve for distinguishing steatosis grades 1, 2, and 3 were 0.887, 0.882, and 0.867, respectively. A skin-to-capsula distance of ≥ 25mm was identified as the only significant factor causing the discrepancy. No interaction between MRI-logPDFF and MRE-LSM on iATT values was observed. Compared to MRI-PDFF, iATT showed excellent diagnostic accuracy in grading steatosis. iATT could be used as a diagnostic tool instead of MRI in clinical practice and trials. Trial registration This study was registered in the UMIN Clinical Trials Registry (UMIN000047411).

Quantitative Comparison of Liver Volume, Proton Density Fat Fraction, and Time Burden between Automatic Whole Liver Segmentation and Manual Sampling MRI Strategies for Diagnosing Metabolic Dysfunction-associated Steatotic Liver Disease in Obese Patients.

The performance of automatic liver segmentation and manual sampling MRI strategies needs be compared to determine interchangeability. To compare automatic liver segmentation and manual sampling strategies (manual whole liver segmentation and standardized manual region of interest) for performance in quantifying liver volume and MRI-proton density fat fraction (MRI-PDFF), identifying steatosis grade, and time burden. Fifty patients with obesity who underwent liver biopsy and MRI between December 2017 and November 2018 were included. Sampling strategies included automatic and manual whole liver segmentation and 4 and 9 large regions of interest. Intraclass correlation coefficient (ICC), Bland-Altman, linear regression, receiver operating characteristic curve, and Pearson correlation analyses were performed. Automatic whole liver segmentation liver volume and manual whole liver segmentation liver volume showed excellent agreement (ICC=0.97), high correlation (R2=0.96), and low bias (3.7%, 95% limits of agreement, -4.8%, 12.2%) in liver volume. There was the best agreement (ICC=0.99), highest correlation (R2=1.00), and minimum bias (0.84%, 95% limits of agreement, -0.20%, 1.89%) between automated whole liver segmentation MRI-PDFF and manual whole liver segmentation MRI-PDFF. There was no difference of each paired comparison of receiver operating characteristic curves for detecting steatosis (P=0.07-1.00). The minimum time burden for automatic whole liver segmentation was 0.32 s (0.32-0.33 s). Automatic measurement has similar effects to manual measurement in quantifying liver volume, MRI-PDFF, and detecting steatosis. Time burden of automatic whole liver segmentation is minimal among all sampling strategies. Manual measurement can be replaced by automatic measurement to improve quantitative efficiency.

Effects of empagliflozin on liver fat in patients with metabolic dysfunction-associated steatotic liver disease without diabetes mellitus: A randomized, double-blind, placebo-controlled trial.

We investigated whether empagliflozin reduces hepatic steatosis in patients with metabolic dysfunction-associated steatotic liver disease without diabetes mellitus. This was an investigator-initiated, double-blind, randomized, placebo-controlled trial recruiting adult subjects from the community. Eligible subjects without diabetes mellitus (fasting plasma glucose < 7 mmol/L and HbA1c < 6.5%) who had magnetic resonance imaging-proton density fat fraction (MRI-PDFF) ≥ 5% were randomly allocated to receive empagliflozin 10 mg daily or placebo (1:1 ratio) for 52 weeks (end of treatment, EOT). MRI-PDFF was conducted at baseline and EOT. The primary outcome was the difference in change of MRI-PDFF between the 2 groups at EOT. Secondary outcomes were hepatic steatosis resolution (MRI-PDFF < 5%), alanine aminotransferase drop ≥ 17 U/L, MRI-PDFF decline ≥ 30%, a combination of both, and changes of anthropometric and laboratory parameters at EOT. All outcomes were based on intention-to-treat analysis. Of 98 recruited subjects (median age: 55.7 y [IQR:49.5-63.4]; male:54 [55.1%]), 97 (empagliflozin:49, placebo:48; median MRI-PDFF:9.7% vs 9.0%) had MRI-PDFF repeated at EOT. The Empagliflozin group had a greater reduction in median MRI-PDFF compared to the placebo group (-2.49% vs. -1.43%; p = 0.025), with a nonsignificant trend of resolution of hepatic steatosis (44.9% vs. 28.6%; p = 0.094). There was no significant difference in alanine aminotransferase drop ≥ 17 U/L (16.3% vs. 12.2%; p = 0.564), MRI-PDFF drop ≥ 30% (49.0% vs. 40.8%; p = 0.417), and composite outcome (8.2% vs. 8.2%; p = 1.000). Empagliflozin group had a greater drop in body weight (-2.7 vs. -0.2 kg), waist circumference (-2.0 vs. 0 cm), fasting glucose (-0.3 vs. 0 mmol/L), and ferritin (-126 vs. -22 pmol/L) (all p < 0.05). Empagliflozin for 52 weeks reduces hepatic fat content in subjects with nondiabetic metabolic dysfunction-associated steatotic liver disease. (ClinicalTrials.gov Identifier: NCT04642261).

Correlation between magnetic resonance imaging proton density fat fraction (MRI-PDFF) and liver biopsy to assess hepatic steatosis in obesity

Obesity is highly associated with Non-alcoholic fatty liver disease (NAFLD) and increased risk of liver cirrhosis and liver cancer-related death. We determined the diagnostic performance of the complex-based chemical shift technique MRI-PDFF for quantifying liver fat and its correlation with histopathologic findings in an obese population within 24 h before bariatric surgery. This was a prospective, cross-sectional, Institutional Review Board-approved study of PDFF-MRI of the liver and MRI-DIXON image volume before bariatric surgery. Liver tissues were obtained during bariatric surgery. The prevalence of NAFLD in the investigated cohort was as high as 94%. Histologic hepatic steatosis grades 0, 1, 2, and 3 were observed in 3 (6%), 25 (50%), 14 (28%), and 8 (16%) of 50 obese patients, respectively. The mean percentages of MRI-PDFF from the anterior and posterior right hepatic lobe and left lobe vs. isolate left hepatic lobe were 15.6% (standard deviation [SD], 9.28%) vs. 16.29% (SD, 9.25%). There was a strong correlation between the percentage of steatotic hepatocytes and MRI-PDFF in the left hepatic lobe (r = 0.82, p < 0.001) and the mean value (r = 0.78, p < 0.001). There was a strong correlation between MRI-derived subcutaneous adipose tissue volume and total body fat mass by dual-energy X-ray absorptiometry, especially at the L2–3 and L4 level (r = 0.85, p < 0.001). MRI-PDFF showed good performance in assessing hepatic steatosis and was an excellent noninvasive technique for monitoring hepatic steatosis in an obese population.

Ultrasound-Derived Fat Fraction for Hepatic Steatosis Assessment: Prospective Study of Agreement With MRI PDFF and Sources of Variability in a Heterogeneous Population.

Background: Metabolic dysfunction-associated steatotic liver disease is a growing global public health concern. Quantitative ultrasound measurements, such as ultrasound-derived fat fraction (UDFF), could provide noninvasive, cost-effective, and portable steatosis evaluation. Objective: To evaluate utility of UDFF for steatosis assessment using PDFF as reference in patients undergoing liver MRI for heterogeneous indications, and to assess UDFF variability. Methods: This prospective study included a primary analysis of 187 patients (mean age, 53.8 years; 112 men, 75 women) who underwent 3-T liver MRI for any clinical indication from December 2020 to July 2021. Patients underwent investigational proton-density fat fraction (PDFF) measurement using MR spectroscopy, and investigational ultrasound with UDFF calculation (mean of 5 intercostal measurements) within 1 hour after MRI. In a subanalysis, 21 of these patients underwent additional UDFF measurements 1, 3, and 5 hours after meal consumption. The study also included repeatability and reproducibility (R&R) analysis of 30 patients (mean age, 26.3 years; 11 men, 20 women) who underwent clinical abdominal ultrasound between November 2022 and January 2023; in these patients, three operators sequentially performed UDFF measurements. Results: In primary analysis, UDFF and PDFF showed intraclass correlation coefficient (ICC) of 0.79. In Bland-Altmananalysis, UDFF and PDFF showed mean difference of 1.5% (95% CI, 0.6-2.4%), with 95% limits of agreement from -11.0% to 14.0%. UDFF exhibited AUC for detecting PDFF at historic thresholds of ≥6.5%, ≥17.4%, and ≥22.1% of 0.90, 0.95, and 0.95, respectively. In subanalysis, mean UDFF was not significantly different across time points with respect to meal consumption (p=.21). In R&R analysis, ICC for intraoperator repeatability ranged from 0.98 to 0.99, and for interoperator reproducibility from 0.90 to 0.96. Visual assessment of patient-level data plots indicated increasing variability of mean UDFF measurements across operators, and of intercostal measurements within individual patients, with increasing steatosis. Conclusion: UDFF showed robust agreement with PDFF, diagnostic performance for steatosis grades, as well as intraoperator repeatability and interoperator reproducibility. Nonetheless, UDFF exhibited bias toward slightly larger values versus PDFF, intraoperator and interoperator variation increased with increasing steatosis. Clinical Impact: UDFF shows promise for steatosis assessment across diverse populations, although continued optimization remains warranted.

Aspirin for Metabolic Dysfunction–Associated Steatotic Liver Disease Without Cirrhosis

ImportanceAspirin may reduce severity of metabolic dysfunction–associated steatotic liver disease (MASLD) and lower the incidence of end-stage liver disease and hepatocellular carcinoma, in patients with MASLD. However, the effect of aspirin on MASLD is unknown.ObjectiveTo test whether low-dose aspirin reduces liver fat content, compared with placebo, in adults with MASLD.Design, Setting, and ParticipantsThis 6-month, phase 2, randomized, double-blind, placebo-controlled clinical trial was conducted at a single hospital in Boston, Massachusetts. Participants were aged 18 to 70 years with established MASLD without cirrhosis. Enrollment occurred between August 20, 2019, and July 19, 2022, with final follow-up on February 23, 2023.InterventionsParticipants were randomized (1:1) to receive either once-daily aspirin, 81 mg (n = 40) or identical placebo pills (n = 40) for 6 months.Main Outcomes and MeasuresThe primary end point was mean absolute change in hepatic fat content, measured by proton magnetic resonance spectroscopy (MRS) at 6-month follow-up. The 4 key secondary outcomes included mean percentage change in hepatic fat content by MRS, the proportion achieving at least 30% reduction in hepatic fat, and the mean absolute and relative reductions in hepatic fat content, measured by magnetic resonance imaging proton density fat fraction (MRI-PDFF). Analyses adjusted for the baseline value of the corresponding outcome. Minimal clinically important differences for study outcomes were not prespecified.ResultsAmong 80 randomized participants (mean age, 48 years; 44 [55%] women; mean hepatic fat content, 35% [indicating moderate steatosis]), 71 (89%) completed 6-month follow-up. The mean absolute change in hepatic fat content by MRS was −6.6% with aspirin vs 3.6% with placebo (difference, −10.2% [95% CI, −27.7% to −2.6%]; P = .009). Compared with placebo, aspirin treatment significantly reduced relative hepatic fat content (−8.8 vs 30.0 percentage points; mean difference, −38.8 percentage points [95% CI, −66.7 to −10.8]; P = .007), increased the proportion of patients with 30% or greater relative reduction in hepatic fat (42.5% vs 12.5%; mean difference, 30.0% [95% CI, 11.6% to 48.4%]; P = .006), reduced absolute hepatic fat content by MRI-PDFF (−2.7% vs 0.9%; mean difference, −3.7% [95% CI, −6.1% to −1.2%]; P = .004]), and reduced relative hepatic fat content by MRI-PDFF (−11.7 vs 15.7 percentage points; mean difference, −27.3 percentage points [95% CI, −45.2 to −9.4]; P = .003). Thirteen participants (32.5%) in each group experienced an adverse event, most commonly upper respiratory tract infections (10.0% in each group) or arthralgias (5.0% for aspirin vs 7.5% for placebo). One participant randomized to aspirin (2.5%) experienced drug-related heartburn.Conclusions and RelevanceIn this preliminary randomized clinical trial of patients with MASLD, 6 months of daily low-dose aspirin significantly reduced hepatic fat quantity compared with placebo. Further study in a larger sample size is necessary to confirm these findings.Trial RegistrationClinicalTrials.gov Identifier: NCT04031729

Validation of a screening panel for pediatric metabolic dysfunction-associated steatotic liver disease using metabolomics.

Metabolic dysfunction-associated steatotic liver disease (MASLD), formerly known as NAFLD, is the most common liver disease in children. Liver biopsy remains the gold standard for diagnosis, although more efficient screening methods are needed. We previously developed a novel NAFLD screening panel in youth using machine learning applied to high-resolution metabolomics and clinical phenotype data. Our objective was to validate this panel in a separate cohort, which consisted of a combined cross-sectional sample of 161 children with stored frozen samples (75% male, 12.8±2.6 years of age, body mass index 31.0±7.0kg/m2, 81% with MASLD, 58% Hispanic race/ethnicity). Clinical data were collected from all children, and high-resolution metabolomics was performed using their fasting serum samples. MASLD was assessed by MRI-proton density fat fraction or liver biopsy and cardiometabolic factors. Our previously developed panel included waist circumference, triglycerides, whole-body insulin sensitivity index, 3 amino acids, 2 phospholipids, dihydrothymine, and 2 unknowns. To improve feasibility, a simplified version without the unknowns was utilized in the present study. Since the panel was modified, the data were split into training (67%) and test (33%) sets to assess the validity of the panel. Our present highest-performing modified model, with 4 clinical variables and 8 metabolomics features, achieved an AUROC of 0.92, 95% sensitivity, and 80% specificity for detecting MASLD in the test set. Therefore, this panel has promising potential for use as a screening tool for MASLD in youth.

MASH Resolution Index: development and validation of a non-invasive score to detect histological resolution of MASH

BackgroundDynamic changes in non-invasive tests, such as changes in alanine aminotransferase (ALT) and MRI proton-density-fat-fraction (MRI-PDFF), may help to detect metabolic dysfunction-associated steatohepatitis (MASH) resolution, but a combination of non-invasive...

Nonalcoholic Fatty Liver Disease, Bone and Muscle Quality in Prolactinoma: A Pilot Study

Objective: Hyperprolactinemia has negative impacts on metabolism and musculoskeletal health. In this study, individuals with active prolactinoma were evaluated for nonalcoholic fatty liver disease (NAFLD) and musculoskeletal health, which are underemphasized in the literature.Methods: Twelve active prolactinoma patients and twelve healthy controls matched by age, gender, and BMI were included. Magnetic resonance imaging-proton density fat fraction (MRI-PDFF) was used to evaluate hepatic steatosis and magnetic resonance elastography (MRE) to evaluate liver stiffness measurement (LSM). Abdominal muscle mass, and vertebral MRI-PDFF was also evaluated with MRI. Body compositions were evaluated by dual energy X-ray absorptiometry (DXA). The skeletal muscle quality (SMQ) was classified as normal, low and weak by using “handgrip strength/appendicular skeletal muscle mass (HGS/ASM)” ratio based on the cut-off values previously stated in the literature.Results: Prolactin, HbA1c and CRP levels were higher in prolactinoma patients (p<0.001, p=0.033 and p=0.035, respectively). The median MRI-PDFF and MRE-LSM were 3.0% (2.01-15.20) and 2.22 kPa (2.0-2.5) in the prolactinoma group and 2.5% (1.65-10.00) and 2.19 kPa (1.92-2.54) in the control group, respectively and similiar between groups. In prolactinoma patients, liver MRI-PDFF showed a positive and strong correlation with the duration of disease and traditional risk factors for NAFLD. Total, vertebral and pelvic bone mineral density was similar between groups, while vertebral MRI-PDFF tended to be higher in prolactinoma patients (p=0.075). Muscle mass and strength parameters were similar between groups, but HGS/ASM tended to be higher in prolactinoma patients (p=0.057). Muscle mass was low in 33.3% of prolactinoma patients and 66.6 of controls. According to SMQ, all prolactinoma patients had normal SMQ, whereas 66.6% of the controls had normal SMQ.Conclusion: Prolactinoma patients demonstrated similar liver MRI-PDFF and MRE-LSM to controls despite their impaired metabolic profile and lower gonadal hormone levels. Hyperprolactinemia may improve muscle quality in prolactinoma patients despite hypogonadism.

Protocol of quantitative ultrasound techniques for noninvasive assessing of hepatic steatosis after bariatric surgery.

Roux-en-Y gastric bypass surgery can effectively improve steatosis, necroinflammatory activity, and hepatic fibrosis in individuals diagnosed with morbid obesity or nonalcoholic steatohepatitis (NASH). Common methods such as body mass index (BMI) to evaluate the postoperative effect of clinical bariatric surgery cannot differentiate subcutaneous fats from visceral fats and muscles. Several Quantitative ultrasound (QUS)-based approaches have been developed to quantify hepatic steatosis. QUS techniques (tissue attenuation imaging (TAI), tissue scatter distribution imaging (TSI)) from radio frequency (RF) data analysis as a means for the detection and grading of hepatic steatosis has been posited as an objective and noninvasive approach. The implementation and standardization of QUS techniques (TAI, TSI) in assessing hepatic steatosis quantitatively after bariatric surgery is of high-priority. Our study is aimed to assess hepatic steatosis with QUS techniques (TAI, TSI) in morbidly obese individuals before and after bariatric surgery, and to compare with anthropometric measurements, laboratory assessments and other imaging methods. The present investigation, a self-discipline examination of navigational capacity devoid of visual cues, is designed as a single-site, forward-looking evaluation of efficacy with the imprimatur of the institutional review board. The duration of the study has been provisionally determined to span from 1 January 2023 through 31 December 2025. Our cohort shall encompass one hundred participants, who was scheduled to undergo Roux-en-Y gastric bypass (RYGB) at Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine. All patients will undergo anthropometric measurements, blood-based biochemical analyses, ultrasonic examination and magnetic resonance imaging proton density fat fraction (MRI-PDFF). The primary endpoint is the analysis of evaluating the efficacy of QUS techniques assessing hepatic steatosis compared to other methods before and after bariatric surgery. Prior to the fomal study, we recruited 21 obese Chinese participants who received ultrasonic examination (TAI, TSI) and MRI-PDFF. AC-TAI showed moderate correlations with MRI-PDFF (adjusted r = 0.632; P < 0.05). For MRI-PDFF ≥10%, SC-TSI showed moderate correlations with MRI-PDFF (adjusted r = 0.677; P < 0.05). Our pre-experiment results signified that using QUS techniques for postoperative evaluation of bariatric surgery is promising. QUS techniques will be signed a widespread availability, real-time functionality, and low-cost approach for assessing hepatic steatosis before and after bariatric surgery in obese individuals, thus is capable for subsequent scale-up liver fat quantification. The present research endeavor has been bestowed with the imprimatur of the Ethics Committee of the Hospital, as indicated by its Approval Number: 2023-KY-015. In due course, upon completion of the study, we intend to disseminate our findings by publishing them in a suitable academic journal, thereby facilitating their widespread utilization. The trial is duly registered with the Chinese Clinical Trial Registry, and with a unique Trial Registration Number, ChiCTR2300069892, approved on March 28, 2023.

Diagnostic Performance of Ultrasound in Detecting Hepatic Steatosis in Non-Alcoholic Fatty Liver Disease Considering MRI Proton Density Fat Fraction as the Reference Standard

Introduction:&amp;nbsp;The increasing incidence of Non-Alcoholic Fatty Liver Disease (NAFLD) will burden the health care system. There is a pressing need to devise an accurate non-invasive method to detect and quantify hepatic steatosis (HS) in NAFLD.Goal:&amp;nbsp;To evaluate the diagnostic efficacy of conventional ultrasound (US) to predict the presence and degree of HS in NAFLD considering MRI Proton Density Fat Fraction (PDFF) as the reference standard.Methods:&amp;nbsp;The study comprised sixty subjects with high clinical suspicion of NAFLD. The US was performed to assess four defined signs (abnormal echogenicity of liver, loss of echogenicity of portal vein, poor diaphragm visualization and posterior beam attenuation). MRI IDEAL IQ software-generated fat-fraction maps were used to measure PDFF values as the average of 24 regions of interest (ROIs) in eight liver segments. The sensitivity, specificity, NPV, PPV and diagnostic accuracy of US signs and their combinations were calculated with the MRI PDFF values (≥6.5 % vs &amp;lt;6.5 %) as the reference standard.Results:&amp;nbsp;The presence of posterior beam attenuation and obscuration of the diaphragm in the US showed excellent sensitivity and NPV (100%) for detecting grade 3 HS. The presence of altered liver echotexture and loss of echogenicity of the portal vein showed excellent sensitivity and NPV (100%) for detecting grade 2 HS.Conclusion:&amp;nbsp;The sensitivity and negative predictive value of various US signs and their combinations for detecting hepatic steatosis were excellent. Thus, the conventional ultrasound must be considered a satisfactory screening tool for the exclusion of NAFLD.

Kidney and liver fat accumulation: from imaging to clinical consequences.

Recent studies indicate that accumulation of adipose tissue in various organs such as liver and kidney may contribute to the pathophysiology of metabolic syndrome. We aim to investigate the association between kidney and liver adipose tissue accumulation, assessed by the magnetic resonance imaging (MRI) proton density fat fraction technique, along with its relation to clinical and biochemical parameters. We included 51 volunteers with phenotypical features of metabolic syndrome (mean age = 34years, mean body-mass index = 26.4kg/m2) in our study in which liver and kidney adipose tissue accumulation was assessed via MRI-proton density fat fraction along with multiple other clinical and biochemical parameters such as estimated glomerular filtration rate (eGFR), urine albumin-to-creatinine ratio, serum lipid profile, liver function tests and body-mass index (BMI). Our results from the univariate linear regression analysis indicate that both the kidney and liver scores were positively correlated with markers such as BMI, urine albumin-to-creatinine ratio, triglycerides (p < 0.001) and negatively correlated with eGFR (p < 0.05). In multivariate analysis, urine albumin-to-creatinine ratio (p < 0.05), triglycerides (p < 0.01), eGFR (p < 0.05) and BMI (p < 0.001) were found to be independently associated with kidney and liver fat accumulation, respectively (R2 = 0.64; R2 = 0.89). There was also a positive correlation between kidney and liver fat accumulation. We have found a significant association between adipose tissue accumulation in liver and kidney and the parameters of metabolic syndrome. Moreover, the presence of a strong association between kidney and liver fat accumulation and kidney function parameters such as urine albumin-to-creatinine ratio and eGFR may be an indicator of the clinical significance of parenchymalfat accumulation.

Diagnostic value of FibroTouch in identifying hepatic steatosis in NAFLD with MRI-PDFF as the reference standard.

To estimate the performance of the FibroTouch-based ultrasound attenuation parameter (UAP) for assessing hepatic steatosis in nonalcoholic fatty liver disease (NAFLD), with magnetic resonance imaging proton density fat fraction (MRI-PDFF) as the reference standard. This prospective, cross-sectional study included 275 individuals in the training group and 110 individuals in the validation group, all of whom completed a standardized research visit, laboratory tests, MRI-PDFF, and UAP measurements over 1 month. Pearson correlation coefficient and Bland-Altman analysis were used to assess the agreement between UAP and MRI-PDFF for the detection of hepatic steatosis. The diagnostic value of UAP was evaluated by the area under the receiver operating characteristic (ROC) curve (AUROC). Confounding factors to UAP performance were identified by ROC curves and regression analyses. The AUROC of UAP for detecting MRI-PDFF at ≥5%, ≥10%, and ≥20% were 0.95 (95% confidence interval [CI] 0.92-0.97), 0.86 (95% CI 0.81-0.90), and 0.90 (95% CI 0.86-0.93), respectively, and their optimal thresholds were 259, 274, and 295 dB/m, respectively. The UAP measurements had higher diagnostic accuracy in participants with lower waist circumference (≤90 cm for men and ≤80 cm for women) compared to those with higher waist circumference (AUROC values: 0.97 vs 0.84, P < 0.05). Bland-Altman analysis showed good agreement between UAP and MRI-PDFF (bias 0.00021). According to established regression analyses, hepatic steatosis could be accurately diagnosed using UAP estimation. FibroTouch-UAP has a high diagnostic potential for hepatic steatosis in NAFLD patients and helps clinical assessment and monitoring.

Prospective Comparison of Attenuation Imaging and Controlled Attenuation Parameter for Liver Steatosis Diagnosis in Patients With Nonalcoholic Fatty Liver Disease and Type 2 Diabetes

Background and aimsSimilarly to the controlled attenuation parameter (CAP), the ultrasound-based attenuation imaging (ATI) can quantify hepatic steatosis. We prospectively compared the performance of ATI and CAP for the diagnosis of hepatic steatosis in patients with type 2 diabetes (T2D) and nonalcoholic fatty liver disease (NAFLD) using histology and magnetic resonance imaging proton density fat fraction (MRI-PDFF) as references. MethodsPatients underwent ATI and CAP measurement, MRI, and biopsy on the same day. Steatosis was classified as S0, S1, S2, and S3 on histology (<5%, 5-33%, 33-66%, and >66%, respectively) while the thresholds of 6.4%, 17.4%, and 22.1%, respectively, were used for MRI-PDFF. The area under the curve (AUC) of ATI and CAP was compared using a DeLong test. ResultsSteatosis could be evaluated in 191 and 187 patients with liver biopsy and MRI-PDFF, respectively.For MRI–PDFF steatosis the AUC of ATI and CAP were 0.86 (95%C.I. 0.81–0.91) vs 0.69 (95%C.I. 0.62-0.75) for S0 vs S1-S3 (p=0.02) and 0.71 (95%C.I. 0.64–0.77) vs 0.69 (95%C.I. 0.61-0.75) for S0-S1 vs S2-S3 (p=0.60), respectively.For histological steatosis the AUC of ATI and CAP were 0.92 (95%C.I. 0.87-0.95) vs. 0.95 (95%C.I. 0.91-0.98) for S0 vs S1-S3 (p=0.64) and 0.79 (95%C.I. 0.72-0.84) vs. 0.76 (95%C.I. 0.69–0.82) for S0-S1 vs S2-S3 (p=0.61), respectively. ConclusionATI may be used as an alternative to CAP for the diagnosis and quantification of steatosis, in patients with T2D and NAFLD.

Ultrasound Attenuation Imaging vs MRI-PDFF, Echogenicity and Liver Function for Assessing Degree of Steatosis in NAFLD and Non-NAFLD Patients.

Nonalcoholic fatty liver disease (NAFLD) is a primary cause of parenchymal liver disease globally. There are currently several methods available to test the degree of steatosis in NAFLD patients, but all have drawbacks that limit their use.The objective of this study is to determine if a new technique, ultrasound (US) attenuation imaging (ATI), correlates with magnetic resonance proton density fat fraction imaging and hepatic echogenicity as seen on gray scale US imaging.Fifty-four patients were recruited at the University of Washington Medical Center from individuals who had already been scheduled for hepatic US or magnetic resonance imaging (MRI). All participants then underwent both hepatic MRI proton density fat fraction and US. Ultrasound images were then evaluated using ATI with 2 observers who individually determined relative grayscale echogenicity.Analysis showed positive correlation between ATI- and MRI-determined fat percentage in the case group (Spearman correlation: 0.50; P = 0.015). Furthermore, participants with NAFLD tended to have a higher ATI than controls (median: 0.70 vs 0.54 dB/cm/MHz; P < 0.001).This study demonstrates that US ATI combined with grayscale imaging is an effective way of assessing the degree of steatosis in patients with moderate to severe NAFLD.

Evaluation of the effects of pemafibrate on metabolic dysfunction-associated steatotic liver disease with hypertriglyceridemia using magnetic resonance elastography combined with fibrosis-4 index and the magnetic resonance imaging-aspartate aminotransferase score.

In this retrospective study, we evaluated the effects of pemafibrate treatment in patients with metabolic dysfunction-associated steatotic liver disease (MASLD) and hypertriglyceridemia using non-invasive stiffness-based models, including magnetic resonance elastography (MRE) combined with the fibrosis-4 (FIB-4) (MEFIB) index and the magnetic resonance imaging (MRI)-aspartate aminotransferase (AST) (MAST) score. In total, 179 patients with MASLD treated with pemafibrate were enrolled. We evaluated the effects of 48-week pemafibrate treatment using the MEFIB index, which classifies patients based on the combination of liver stiffness measurement (LSM) on MRE and FIB-4 and the MAST score, which is calculated based on LSM on MRE, MRI-proton density fat fraction (MRI-PDFF), and AST levels. Pemafibrate treatment led to significant reduction in AST, alanine aminotransferase (ALT), and gamma-glutamyl transferase (GGT) (P = 0.011, <0.001, and <0.001, respectively) and significant improvements in triglyceride and high-density lipoprotein cholesterol levels (P < 0.001 and <0.001, respectively). The MRI-PDFF values were not significantly altered. However, a significant decrease in LSM on MRE was detected (P = 0.003). Evaluation of fibrosis using the MEFIB index and MAST score demonstrated significant improvement (P = 0.004 and <0.001, respectively). Changes in the MAST score showed positive correlation with changes in ALT and GGT levels (r = 0.821, P < 0.001, and r = 0.808, P < 0.001, respectively). Additionally, ALT and GGT levels at baseline were significantly associated with improvements in the MAST score (P < 0.001 and <0.001, respectively). Pemafibrate led to improvements in the MEFIB index and MAST score, as well as liver function. It is a promising therapeutic agent for patients with MASLD and hypertriglyceridemia with the potential to reduce liver-related events.