Magnetic Resonance Imaging-proton Density Fat Research Articles

Ultrasound-estimated hepatorenal index: diagnostic performance and interobserver agreement for pediatric liver fat quantification.

Semiquantitative and quantitative sonographic techniques have the potential for screening and surveillance of children at risk of nonalcoholic fatty liver disease. To determine diagnostic performance and interobserver agreement of hepatorenal index (HRI) for pediatric ultrasound-based liver fat quantification. In an institutional review board (IRB)-approved retrospective study (April 2014 to April 2023), children (< 18years) with clinically performed magnetic resonance imaging (MRI) scans for liver fat quantification were assessed. Inclusion criteria required availability of abdominal ultrasound within 3months of quantitative MRI. Three blinded readers subjectively assessed for sonographic hepatic steatosis and calculated HRI. MRI proton density fat fraction (PDFF) was the reference standard. Interobserver agreement, correlation with PDFF, and optimal HRI (using ROC analysis) values were analyzed. The significance level was set at p < 0.05. A total of 41 patients (25 male) with median (interquartile range (IQR)) age of 13 (10-15) years were included. Median (IQR) MRI PDFF was 11.30% (2.70-17.95%). Hepatic steatosis distribution by MRI PDFF included grade 0 (34%), grade 1 (15%), grade 2 (22%), and grade 3 (29%) patients. Intraclass correlation coefficient for HRI among the three readers was 0.61 (95% CI 0.43-0.75) (p < 0.001). Moderate correlation was observed between manually estimated HRI and PDFF for each reader (r = 0.62, 0.67, and 0.67; p < 0.001). Optimal HRI cutoff was found to be 1.99 to diagnose hepatic steatosis (sensitivity 89%, specificity 93%). Median (IQR) HRI for each MRI grade of hepatic steatosis (0-4) was as follows: 1.2 (1.1-1.5), 2.6 (1.1-3.3), 3.6 (2.6-5.4), 5.6 (2.6-10.9), respectively (p < 0.001). Ultrasound-estimated HRI has moderate interobserver agreement and moderate correlation with MRI-derived PDFF. HRI of 1.99 maximizes accuracy for identifying pediatric liver fat.

Alcoholic Liver Disease/Nonalcoholic Fatty Liver Disease Index for Classification of Patients with Steatotic Liver Disease.

Steatotic liver disease (SLD) encompasses metabolic dysfunction-associated steatotic liver disease (MASLD) and alcohol-associated liver disease (AALD) at extremes as well as an overlap group termed MASLD with increased alcohol intake (MetALD). The Alcoholic Liver Disease/Nonalcoholic Fatty Liver Disease Index (ANI) was proposed to differentiate ALD from nonalcoholic fatty liver disease (NAFLD). We analysed the performance of the ANI in differentiating within the SLD spectrum. In a cross-sectional study at a tertiary care center, 202 adults (>18 years) who were prospectively diagnosed with SLD defined by magnetic resonance imaging-proton density fat fraction >6.4% were enrolled. Alcohol consumption (AC) was recorded according to thresholds for significant AC: 140-350 g/week (or 20-50 g/day) for females and 210-420 g/week (or 30-60 g/day) for males. The ANI was calculated, and area under the receiver operating characteristic curve (AUROC) was generated. Of 202 patients (47 years [interquartile range, IQR, 38 to 55], 23.75% females, 77% obese, 42.1% with diabetes, 38.1% hypertensive, 28.7% statin use), 40.5% were ever-alcohol consumers; 120 (59%), 50 (24.7%), and 32 (15.8%) were MASLD (ANI, -3.7 [IQR, -7 to -1.6]; MetALD, - 1.45 [IQR, -2.4 to 0.28]; and AALD, 0.71 [IQR, -1.3 to 4.8], respectively; P<0.05 for all). The AUROC of the ANI for MASLD and AALD was 0.79 (IQR, 0.72 to 0.84; cut-off <-3.5) and 0.80 (IQR, 0.74 to 0.86; cut-off >-1.49), respectively. The ANI outperformed aspartate transaminase/alanine transaminase (AST/ALT) ratio (AUROC=0.75 [IQR, 0.69 to 0.81]) and gamma glutamyl transpeptidase (GGT) (AUROC=0.74 [IQR, 0.67 to 0.80]). Addition of GGT did not improve model performance (AUCdiff=0.004; P=0.33). AC is common in MASLD. The ANI distinguishes MASLD and AALD, with individual cut-offs within the intermediate zone indicating MetALD. ANI also outperforms AST/ALT ratio or GGT.

SomaLogic proteomics reveals new biomarkers and provides mechanistic, clinical insights into Acetyl coA Carboxylase (ACC) inhibition in Non-alcoholic Steatohepatitis (NASH)

Non-alcoholic Fatty Liver Disease (NAFLD) and Non-alcoholic Steatohepatitis (NASH) are major metabolic diseases with increasing global prevalence and no approved therapies. There is a mounting need to develop biomarkers of diagnosis, prognosis and treatment response that can effectively replace current requirements for liver biopsies, which are invasive, error-prone and expensive. We performed SomaLogic serum proteome profiling with baseline (n = 231) and on-treatment (n = 72, Weeks 12 and 16, Placebo and 25 mg PF-05221304) samples from a Phase 2a trial (NCT03248882) with Clesacostat (PF-05221304), an acetyl coA carboxylase inhibitor (ACCi) in patients with NAFLD/NASH. SomaSignal NASH probability scores and expression data for 7000+ analytes were analyzed to identify potential biomarkers associated with baseline clinical measures of NAFLD/NASH [Magnetic Resonance Imaging-Proton Density Fat Fraction (MRI-PDFF), alanine aminotransferase (ALT) and aspartate aminotransferase (AST)] as well as biomarkers of treatment response to ACCi. SomaSignal NASH probability scores identified biopsy-proven/clinically defined NIT-based (Presumed) NASH classification of the cohort with > 70% agreement. Clesacostat-induced reduction in steatosis probability scores aligned with observed clinical reduction in hepatic steatosis based on MRI-PDFF. We identify a set of 69 analytes that robustly correlate with clinical measures of hepatic inflammation and steatosis (MRI-PDFF, ALT and AST), 27 of which were significantly reversed with ACC inhibition. Clesacostat treatment dramatically upregulated Wnt5a protein and Apolipoproteins C3 and E, with drug-induced changes significantly correlating to changes on MRI-PDFF. Our data demonstrate the utility of SomaLogic- analyte panel for diagnosis and treatment response in NAFLD/NASH and provide potential new mechanistic insights into liver steatosis reduction, inflammation and serum triglyceride elevation with ACC inhibition. (Clinical Trial Identifier: NCT03248882).

Effect of pemvidutide, a GLP-1/glucagon dual receptor agonist, on MASLD: A randomized, double-blind, placebo-controlled study

This was a randomized, double-blind, placebo-controlled study to assess the effects of pemvidutide, a glucagon-like peptide-1 (GLP-1)/glucagon dual receptor agonist, on liver fat content (LFC) in subjects with metabolic dysfunction-associated steatotic liver disease (MASLD). Subjects with a BMI ≥28.0 kg/m2 and LFC ≥10% by magnetic resonance imaging-proton density fat fraction were randomized 1:1:1:1 to pemvidutide at 1.2 mg, 1.8 mg, or 2.4 mg, or placebo administered subcutaneously once weekly for 12 weeks. Participants were stratified according to a diagnosis of type 2 diabetes mellitus (T2DM). The primary efficacy endpoint was relative reduction (%) from baseline in LFC after 12 weeks of treatment. 94 subjects were randomized and dosed. Median baseline BMI and LFC across the study population were 36.2 kg/m2 and 20.6%; 29% of subjects had T2DM. At Week 12, relative reductions in LFC from baseline were (1.2 mg) 46.6% [95% CI -63.7 to -29.6], (1.8 mg) 68.5% [95% CI -84.4 to -52.5], and (2.4 mg) 57.1% [95% CI -76.1 to -38.1] versus 4.4% [95% CI -20.2 to 11.3] in placebo subjects (p <0.001 vs. placebo, all treatment groups), with 94.4% and 72.2% of subjects achieving 30% and 50% reductions in LFC and 55.6% achieving normalization (≤5% LFC) at the 1.8 mg dose. Maximal responses for weight loss (-4.3%; p <0.001), alanine aminotransferase (-13.8 IU/L; p = 0.029), and corrected cT1 (-75.9 ms; p = 0.002) were all observed at the 1.8 mg dose. Pemvidutide was well-tolerated at all doses with no severe or serious adverse events. In subjects with MASLD, weekly pemvidutide treatment yielded significant reductions in LFC, markers of hepatic inflammation, and body weight compared to placebo. MASLD, and MASH, are strongly associated with overweight and obesity and it is believed that the excess liver fat associated with obesity is an important driver of these diseases. Glucagon-like peptide-1 receptor (GLP-1R) agonists elicit weight loss through centrally and peripherally mediated effects on appetite. Unlike GLP-1R agonists, glucagon receptor (GCGR) agonists act directly on the liver to stimulate fatty acid oxidation and inhibit lipogenesis, potentially providing a more potent mechanism for liver fat content (LFC) reduction than weight loss alone. This study demonstrated the ability of once-weekly treatment with pemvidutide, a dual GLP-1R/GCGR agonist, to significantly reduce LFC, hepatic inflammatory activity, and body weight, suggesting that pemvidutide may be an effective treatment for both MASH and obesity. NCT05006885.

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.

Ultrasound-based steatosis grading system using 2D-attenuation imaging: An individual patient data meta-analysis with external validation.

Noninvasive tools assessing steatosis, such as ultrasonography-based 2D-attenuation imaging (ATI), are needed to tackle the worldwide burden of steatotic liver disease. This one-stage individual patient data (IPD) meta-analysis aimed to create an ATI-based steatosis grading system. A systematic review (EMBASE + MEDLINE, 2018-2022) identified studies, including patients with histologically or magnetic resonance imaging proton-density fat fraction (MRI-PDFF)-verified ATI for grading steatosis (S0 to S3). One-stage IPD meta-analyses were conducted using generalized mixed models with a random study-specific intercept. Created ATI-based steatosis grading system (aS0 to aS3) was externally validated on a prospective cohort of patients with type 2 diabetes and metabolic dysfunction-associated steatotic liver disease (n=174, histologically and MRI-PDFF-verified steatosis). Eleven enrolled studies included 1374 patients, classified into S0, S1, S2, and S3 in 45.4%, 35.0%, 9.3%, and 10.3% of the cases. ATI was correlated with histological steatosis ( r = 0.60; 95% CI: 0.52, 0.67; p < 0.001) and MRI-PDFF ( r = 0.70; 95% CI: 0.66, 0.73; p < 0.001) but not with liver stiffness ( r = 0.03; 95% CI: -0.04, 0.11, p = 0.343). Steatosis grade was an independent factor associated with ATI (coefficient: 0.24; 95% CI: [0.22, 0.26]; p < 0.001). ATI marginal means within S0, S1, S2, and S3 subpopulations were 0.59 (95% CI: [0.58, 0.61]), 0.69 (95% CI [0.67, 0.71]), 0.78 (95% CI: [0.76, 0.81]), and 0.85 (95% CI: [0.83, 0.88]) dB/cm/MHz; all contrasts between grades were significant ( p < 0.0001). Three ATI thresholds were calibrated to create a new ATI-based steatosis grading system (aS0 to aS3, cutoffs: 0.66, 0.73, and 0.81dB/cm/MHz). Its external validation showed Obuchowski measures of 0.84 ± 0.02 and 0.82 ± 0.02 with histologically based and MRI-PDFF-based references. ATI is a reliable, noninvasive marker of steatosis. This validated ATI-based steatosis grading system could be valuable in assessing patients with metabolic dysfunction-associated steatotic liver disease.

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).

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).

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.

Addition of Dulaglutide or Empagliflozin to Standard-of-Care Treatment: Effect on Liver Steatosis in Patients With Type 2 Diabetes Mellitus.

Background Patients with liver steatosis and diabetes mellitus can benefit from medications like glucagon-like peptide 1 receptor agonists or sodium-glucose co-transporter 2 inhibitors, as far as both hyperglycemia and fatty liver are concerned. Studies comparing members of both these families have not yet been published. We aimed to compare the effects of Empagliflozin and Dulaglutide, focusing primarily on liver steatosis. Methodology This prospective, observational, controlled study enrolled 78 patients from two centers in Athens, Greece. Adults with type 2 diabetes mellitus (DM2) and nonalcoholic fatty liver disease were assigned to one of three groups and received either Empagliflozin or Dulaglutide or any other medical treatment deemed appropriate by their physician. The primary endpoint was the reduction in liver fat fraction, assessed using magnetic resonance imaging-proton density fat fraction. Additionally, we evaluated the proportion of patients achieving a relative reduction above 30% of their initial liver fat concentration. Results The Empagliflozin group exhibited a reduction in liver fat fraction. Furthermore, the percentage of patients with a relative reduction of liver steatosis, >30%, was significantly larger in this group, compared to the Dulaglutide and Control groups. Significant body weight reduction was observed in all three groups, but no improvement in fibrosis assessing scores was noted. Conclusions Empagliflozin is effective in improving liver steatosis, while Dulaglutide does not exhibit a similar effect. Larger studies, comparing these or related agents, are necessary,to further assess benefits in patients with DM2 and nonalcoholic fatty liver.

Nonalcoholic Fatty Liver Disease and Staging of Hepatic Fibrosis.

Nonalcoholic fatty liver disease (NAFLD) is in parallel with the obesity epidemic, and it is the most common cause of liver diseases. The patients with severe insulin-resistant diabetes having high body mass index (BMI), high-grade adipose tissue insulin resistance, and high hepatocellular triacylglycerols (triglycerides; TAG) content develop hepatic fibrosis within a 5-year follow-up. Insulin resistance with the deficiency of insulin receptor substrate-2 (IRS-2)-associated phosphatidylinositol 3-kinase (PI3K) activity causes an increase in intracellular fatty acid-derived metabolites such as diacylglycerol(DAG), fatty acyl CoA, or ceramides. Lipotoxicity-related mechanism of NAFLD could be explained still best by the "double-hit" hypothesis. Insulin resistance is the major mechanism in the development and progression of NAFLD/nonalcoholic steatohepatitis (NASH). Metabolic oxidative stress, autophagy, and inflammation induce NASH progression. In the "first hit" the hepatic concentrations of diacylglycerol increase with an increase in saturated liver fat content in human NAFLD. Activities of mitochondrial respiratory chain complexes are decreased in the liver tissue of patients with NASH. Hepatocyte lipoapoptosis is a critical feature of NASH. In the "second hit," reduced glutathione levels due to oxidative stress lead to the overactivation of c-Jun N-terminal kinase (JNK)/c-Jun signaling that induces cell death in the steatotic liver. Accumulation of toxic levels of reactive oxygen species (ROS) is caused at least by two ineffectual cyclical pathways. First is the endoplasmic reticulum (ER) oxidoreductin (Ero1)-protein disulfide isomerase oxidation cycle through the downstream of the inner membrane mitochondrial oxidative metabolism and the second is the Kelch like-ECH-associated protein 1 (Keap1)-nuclear factor (erythroid-derived 2)-like 2 (Nrf2) pathways. In clinical practice, on ultrasonographic examination, the elevation of transaminases, γ-glutamyltransferase, and the aspartate transaminase to platelet ratio index indicates NAFLD. Fibrosis-4 index, NAFLD fibrosis score, and cytokeratin18 are used for grading steatosis, staging fibrosis, and discriminating the NASH from simple steatosis, respectively. In addition to ultrasonography, "controlled attenuation parameter," "magnetic resonance imaging proton-density fat fraction," "ultrasound-based elastography," "magnetic resonance elastography," "acoustic radiation force impulse elastography imaging," "two-dimensional shear-wave elastography with supersonic imagine," and "vibration-controlled transient elastography" are recommended as combined tests with serum markers in the clinical evaluation of NAFLD. However, to confirm the diagnosis of NAFLD, a liver biopsy is the gold standard. Insulin resistance-associated hyperinsulinemia directly accelerates fibrogenesis during NAFLD development. Although hepatocyte lipoapoptosis is a key driving force of fibrosis progression, hepatic stellate cells and extracellular matrix cells are major fibrogenic effectors. Thereby, these are pharmacological targets of therapies in developing hepatic fibrosis. Nonpharmacological management of NAFLD mainly consists of two alternatives: lifestyle modification and metabolic surgery. Many pharmacological agents that are thought to be effective in the treatment of NAFLD have been tried, but due to lack of ability to attenuate NAFLD, or adverse effects during the phase trials, the vast majority could not be licensed.

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 Hematopoiesis and Disease Status in Patients with Hematologic Malignancies Using Whole-Body Bone Marrow Imaging with 18 F-FLT PET/MRI

Introduction Bone marrow examination is primarily focused on a limited region of the ilium, thereby inadequately assessing systemic hematopoiesis or residual tumor cells after therapy. Magnetic resonance imaging (MRI) of the spine can examine the fat marrow, but does not provide a direct assessment of hematopoietic cells. The use of the radiopharmaceutical 3‘-deoxy-3‘- 18F-fluorothymidine ( 18F-FLT) positron emission tomography (PET), which measures nucleic acid synthesis, can provide a quantifiable means of assessing hematopoietic cell proliferation. The combination of whole-body MRI and 18F-FLT PET may provide a more accurate assessment of whole-body bone marrow hematopoiesis in hematologic malignancies. Methods A prospective, open-label, exploratory study (UMIN000041491) was conducted to evaluate hematopoiesis using 18F-FLT PET/MRI imaging in patients planned for allogeneic hematopoietic stem cell transplantation. Subjects were patients over 20 years of age with hematologic malignancies who underwent 18F-FLT PET/MRI imaging before transplantation and at 50 and 180 days after transplantation. After an intravenous injection of 185 MBq 18F-FLT, patients were transferred to a simultaneous 3.0 T PET/MR scanner (Signa PET/MR; GE Healthcare, Waukesha, WI). The PET acquisition was performed in 3D mode with a 5.5 min/bed position (89 slices/bed) and a 24-slice overlap in 5 to 6 beds. The percentage of fat marrow was determined using MRI proton density fat fraction (PDFF) with a 1 cm 2 region of interest at 26 sites: cervical spine (C2-C7), thoracic spine (Th1-Th12), lumbar spine (L1-L5), and superior posterior iliac spine (two sites on each side). Similarly, the standardized uptake value (SUV) of 18F-FLT was measured. Results Thirteen patients with hematologic malignancies (8 with acute myeloid leukemia, 2 with acute lymphoblastic leukemia, and 3 with malignant lymphoma) were evaluated between August 2020 and April 2023. The median age of the patients was 46 years (range: 23 ~ 65). Seven patients underwent cord blood transplantation, while the remainder received peripheral blood stem cell transplantation. Prior to transplantation, all 13 patients underwent 18F-FLT PET/MRI scans. After transplantation, due to treatment-related death or worsening of the primary disease, 11 patients underwent scans on day 50, while 8 patients underwent scans on day 180, resulting in a total of 32 evaluable scans. In the 28 cases in hematologic remission at imaging, mean PDFF values were higher in the iliac (63.3% ± standard deviation 13.9) and lumbar (60.4% ± 14.9) than in the thoracic (47.2% ± 17.1) and cervical (37.5% ± 14.8) spines. Conversely, mean 18F-FLT SUV was higher in the thoracic (6.98 ± 2.31) and cervical (6.82 ± 2.03) than in the lumbar (5.06 ± 2.39) and iliac (3.95 ± 1.88) spine. This site-specific disparity in PDFF and 18F-FLT SUV was consistent both before and after transplantation. In all 32 cases, the median correlation coefficient between PDFF and 18F-FLT SUV was -0.60 (range: -0.92 ~ 0.17, Pearson's cumulative correlation coefficient), and 25 cases (78.1%) had a negative correlation coefficient below -0.4. Comparing the 12 cases with residual disease (4 cases with hematologic non-remission and 8 cases with hematologic remission but abnormal G-banding or quantitative polymerase chain reaction) with the 20 cases in complete remission, the correlation between PDFF and 18F-FLT SUV was significantly weaker in the residual disease group (-0.37 vs. -0.75, p&amp;lt;0.001, Mann-Whitney U test). When the correlation coefficient threshold was set at -0.57, the ROC curve for determining residual disease had an AUC of 0.86, a sensitivity of 83.3%, and a specificity of 85.0%. Discussion It is important to understand that the fat marrow and hematopoiesis degree in the iliac bone differs from that in the thoracic and cervical spine throughout the transplantation process, thereby influencing the disease status evaluation in hematological malignancies. The correlation between PDFF and 18F-FLT SUV, which is strong in cases of remission, weakens in cases of residual disease, even at the level of minimal residual disease. This discrepancy may reflect aberrant tumorigenic cell proliferation that differs from the norm. Thus, 18F-FLT PET/MRI was useful in understanding the hematopoietic and disease state of the systemic bone marrow in patients with hematologic malignancies.

Potential of MRI (Magnetic Resonance Imaging) Proton Density Fat Fraction for the Assessment of Liver Disorders

Proton density fat fraction MRI is a special MRI method used to evaluate liver disorders, especially in terms of assessing fat accumulation in the liver. PDFF MRI is based on the principle of magnetic resonance of hydrogen nuclei in the human body. Our bodies contain many hydrogen atoms, mainly in the form of water and fat. These hydrogen atoms will give different signals in response to magnetic fields and radiofrequency waves. Liver disorders, such as steatosis or fatty liver, are characterized by the accumulation of fat in liver cells. The literature search process was carried out on various databases (PubMed, Web of Sciences, EMBASE, Cochrane Libraries, and Google Scholar) regarding the Potential of MRI (magnetic resonance imaging) proton density fat fraction for the assessment of liver disorders. This study follows the preferred reporting items for systematic reviews and meta-analysis (PRISMA) recommendations. Proton Density Fat Fraction (PDFF) MRI is a medical imaging technique that focuses on the magnetic resonance of hydrogen nuclei in the human body. This is a very effective method in the assessment of liver disorders related to fat accumulation, such as steatosis or fatty liver. PDFF MRI has very high accuracy in measuring the amount of fat in the liver, even in small amounts, thus providing very precise information about the level of fat accumulation.

Effect of 12-week intermittent calorie restriction compared to standard of care in patients with nonalcoholic fatty liver disease: a randomized controlled trial

BackgroundNonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease. NAFLD can result in various complications. Owing to the lack of effective pharmacological therapies, lifestyle modifications are the cornerstone treatment for NAFLD. However, there has been no recommendation for a specific dietary therapy. Because no significant effects have been observed in previous studies. Intermittent calorie restriction (ICR) consists of alternating phases of extreme energy restriction and regular energy intake. Recent studies have demonstrated a significantly higher reduction in liver fat content in the ICR group than in the standard of care (SOC) or continuous calorie restriction groups in patients with NAFLD. However, critical weaknesses limit the broader application of ICR in clinical practice; those are a lack of appropriate assessment tools, different cutoffs of body mass index (BMI) used to define obesity, and different food portions. Thus, we report a protocol for a prospective, randomized controlled trial. The trial will evaluate the effect of 12-week ICR on improving liver fat content in NAFLD patients (Nonalcoholic Fatty Liver Disease-Intermittent Calorie Restriction [FLICR]).MethodsWe will include adult (19–75 years) NAFLD patients. NAFLD will be diagnosed by histologic assessment or magnetic resonance imaging-proton density fat fraction (MRI-PDFF) ≥ 8%. A total of 72 patients will be classified according to BMI (obese group: BMI ≥ 25 kg/m2 [n = 36] and non-obese group: BMI < 25 kg/m2 [n = 36]). Participants will be followed up for 24 weeks. Participants will be randomly assigned to one of the two groups: the SOC or ICR group. The primary objective will be the change in liver fat content measured using MRI-PDFF from baseline to 12 weeks.DiscussionThis FLICR study may provide clinical evidence on ICR in the treatment of NAFLD in both obese and non-obese patients. The use of ICR in patients with NAFLD will improve the clinical outcomes of patients facing a shortage of effective medical therapy.Trial registrationThis trial was registered at the United States National Library of Medicine (NLM) at the National Institutes of Health. ClinicalTrials.gov NCT05309642. Registered on April 4, 2022.

Portable electrical impedance tomography (EIT) system stages non-alcoholic fatty liver disease for potential screening and monitoring at home.

This study demonstrates the feasibility of predicting NAFLD using multi-spectral electrical impedance tomography (EIT), group source separation, constant reference EIT and anthropometric measures. Vibration-controlled Transient Elastography (VCTE) Controlled Attenuated Parameter (CAP; n = 121) and magnetic resonance imaging-proton density fat fraction (MRI-PDFF; n = 34) achieved a sensitivity of 70.9% and specificity of 73.8% with our CAP predicting model and sensitivity of 77.8% and specificity of 80.0% with our MRI-PDFF predicting model. In summary, a portable EIT can be a cost-effective and self-administrable alternative for widespread home-based and community-based diagnostic screening and treatment monitoring of NAFLD.Clinical Relevance- Portable multi-spectral EIT system has the sensitivity and specificity to potentially unlock biomedical imaging in telemedicine for home-based and community-based screening, staging and monitoring for NAFLD.

Associations Between Hepatic and Pancreatic Steatosis with Lumbar Spinal Bone Marrow Fat: A Single-Center Magnetic Resonance Imaging Study.

To evaluate the associations between hepatic, pancreatic steatosis, and lumbar spinal bone marrow fat determined by magnetic resonance imaging-proton density fat fraction in patients with no known or suspected liver disease. A total of 200 patients who were referred to our radiology department for upper abdominal magnetic resonance imaging between November 2015 and November 2017 were included in this study. All patients underwent a magnetic resonance imaging-proton density fat fraction on a 1.5-T magnetic resonance imaging system. The mean liver, pancreas, and lumbar magnetic resonance imaging-proton density fat fraction were 7.52 ± 4.82%, 5.25 ± 5.44%, and 46.85 ± 10.38% in the study population. There were significant correlations between liver and pancreas (rs = 0.180, P = .036), liver and lumbar (rs = 0.317, P < .001), and pancreas and lumbar magnetic resonance imaging-proton density fat fraction (rs = 0.215, P = .012) in female patients. A weak correlation was observed between liver and lumbar magnetic resonance imaging-proton density fat fraction (rs = 0.174, P = .014) in the total population. The prevalence of hepatic and pancreatic steatosis was 42.5% and 29%, respectively. The prevalence of pancreatic steatosis (42.9% vs. 22.8%, P = .004) was higher in male patients compared to female patients. In subgroup analysis, in patients with hepatic steatosis, there were higher pancreas magnetic resonance imaging-proton density fat fraction (6.07 ± 6.42% vs. 4.66 ± 4.53%, P = .036) and lumbar magnetic resonance imaging-proton density fat fraction (48.81 ± 10.01% vs. 45.40 ± 10.46%, P =.029) compared to patients without hepatic steatosis. In patients with pancreatic steatosis, there were higher liver (9.07 ± 6.08 vs. 6.87 ± 4.06, P = .009) and lumbar magnetic resonance imaging-proton density fat fraction (49.31 ± 9.13% vs.45.83 ± 10.76%, P = .032) in comparison with patients without pancreatic steatosis. Based on the results of the present study, fat accumulation in liver, pancreas, and lumbar vertebra have associations with more evident in females.

Clinical and histologic factors associated with discordance between steatosis grade derived from histology vs. MRI-PDFF in NAFLD.

Magnetic resonance imaging-proton density fat fraction (MRI-PDFF) is an excellent biomarker for the non-invasive quantification of hepatic steatosis. To examine clinical and histologic factors associated with discordance between steatosis grade determined by histology and MRI-PDFF in patients with non-alcoholic fatty liver disease (NAFLD) METHODS: We included 728 patients with biopsy-proven NAFLD from UC San Diego (n = 414) and Yokohama City University (n = 314) who underwent MRI-PDFF and liver biopsy. Patients were stratified by steatosis, and matched with MRI-PDFF cut-points for each steatosis grade: 0 (MRI-PDFF < 6.4%), 1 (MRI-PDFF: 6.4%-17.4%), 2 (MRI-PDFF: 17.4%-22.1%), 3 (MRI-PDFF ≥ 22.1%). Primary outcome was major discordance defined as ≥2 steatosis grade difference determined by histology and MRI-PDFF. Mean (±SD) age and BMI were 55.3 (±13.8) years and 29.9 (±4.9) kg/m2 , respectively. The distributions of histology and MRI-PDFF-determined steatosis were 5.5% grade 0 (n = 40), 44.8% 1 (n = 326, 44.8%), 33.9% 2 (n = 247), and 15.8% 3 (n = 115) vs. 23.5% grade 0 (n = 171), 49.7% 1 (n = 362), 12.9% 2 (n = 94), and 13.9% 3 (n = 101). Major discordance rate was 6.6% (n = 48). Most cases with major discordance had greater histology-determined steatosis grade (n = 40, 88.3%), higher serum AST and liver stiffness, and greater likelihood of fibrosis ≥2, ballooning ≥1 and lobular inflammation ≥2 (all p < 0.05). Histology overestimates steatosis grade compared to MRI-PDFF. Patients with advanced NASH are likely to be upgraded on steatosis grade by histology. These data have important implications for steatosis estimation and reporting on histology in clinical practice and trials, especially in patients with stage 2 fibrosis.

SAT-476 - Fatty liver score: a novel fatty liver index based on magnetic resonance imaging-proton density fat fraction

SAT-476 - Fatty liver score: a novel fatty liver index based on magnetic resonance imaging-proton density fat fraction