Hepatic steatosis modeling and MRI signal simulations for comparison of single- and dual-R2* models and estimation of fat fraction at 1.5T and 3T.

BACKGROUND AND OBJECTIVE: Magnetic resonance imaging (MRI) has emerged as a noninvasive clinical tool for assessment of hepatic steatosis. Multi-spectral fat-water MRI models, incorporating single or dual transverse relaxation decay rate(s) (R2*) have been proposed for accurate fat fraction (FF) estimation. However, it is still unclear whether single- or dual-R2* model accurately mimics in vivo signal decay for precise FF estimation and the impact of signal-to-noise ratio (SNR) on each model performance. Hence, this study aims to construct virtual steatosis models and synthesize MRI signals with different SNRs to systematically evaluate the accuracy of single- and dual-R2* models for FF and R2* estimations at 1.5T and 3.0T. METHODS: Realistic hepatic steatosis models encompassing clinical FF range (0-60 %) were created using morphological features of fat droplets (FDs) extracted from human liver biopsy samples. MRI signals were synthesized using Monte Carlo simulations for noise-free (SNRideal) and varying SNR conditions (5-100). Fat-water phantoms were scanned with different SNRs to validate simulation results. Fat water toolbox was used to calculate R2* and FF for both single- and dual-R2* models. The model accuracies in R2* and FF estimates were analyzed using linear regression, bias plot and heatmap analysis. RESULTS: The virtual steatosis model closely mimicked in vivo fat morphology and Monte Carlo simulation produced realistic MRI signals. For SNRideal and moderate-high SNRs, water R2* (R2*W) by dual-R2* and common R2* (R2*com) by single-R2* model showed an excellent agreement with slope close to unity (0.95-1.01) and R2 > 0.98 at both 1.5T and 3.0T. In simulations, the R2*com-FF and R2*W-FF relationships exhibited slopes similar to in vivo calibrations, confirming the accuracy of our virtual models. For SNRideal, fat R2* (R2*F) was similar to R2*W and dual-R2* model showed slightly higher accuracy in FF estimation. However, in the presence of noise, dual-R2* produced higher FF bias with decreasing SNR, while leading to only marginal improvement for high SNRs and in regions dominated by fat and water. In contrast, single-R2* model was robust and produced accurate FF estimations in simulations and phantom scans with clinical SNRs. CONCLUSION: Our study demonstrates the feasibility of creating virtual steatosis models and generating MRI signals that mimic in vivo morphology and signal behavior. The single-R2* model consistently produced lower FF bias for clinical SNRs across entire FF range compared to dual-R2* model, hence signifying that single-R2* model is optimal for assessing hepatic steatosis.

Global trends in hepatitis C-related hepatocellular carcinoma mortality: A public database analysis (1999-2019).

BACKGROUND: Hepatitis C is the leading cause of chronic liver disease worldwide and it significantly contributes to the burden of hepatocellular carcinoma (HCC). However, there are marked variations in the incidence and mortality rates of HCC across different geographical regions. With the advent of new widely available treatment modalities, such as direct-acting antivirals, it is becoming increasingly imperative to understand the temporal and geographical trends in HCC mortality associated with Hepatitis C. Furthermore, gender disparities in HCC mortality related to Hepatitis C are a crucial, yet underexplored aspect that adds to the disease's global impact. While some studies shed light on gender-specific trends, there is a lack of comprehensive data on global and regional mortality rates, particularly those highlighting gender disparities. This gap in knowledge hinders the development of targeted interventions and resource allocation strategies. AIM: To understand the global and regional trends in Hepatitis C-related HCC mortality rates from 1990 to 2019, along with gender disparities. METHODS: We utilized the Global Burden of Disease database, a comprehensive repository for global health metrics to age-standardized mortality rates due to Hepatitis C-related HCC from 1999 to 2019. Rates were evaluated per 100000 population and assessed by World Bank-defined regions. Temporal trends were determined using Joinpoint software and the Average Annual Percent Change (AAPC) method, and results were reported with 95% confidence intervals (CI). RESULTS: From 1990 to 2019, overall, there was a significant decline in HCC-related mortality rates with an AAPC of -0.80% (95%CI: -0.83 to -0.77). Females demonstrated a marked decrease in mortality with an AAPC of -1.06% (95%CI: -1.09 to -1.03), whereas the male cohort had a lower AAPC of -0.52% (95%CI: -0.55 to -0.48). Regionally, East Asia and the Pacific demonstrated a significant decline with an AAPC of -2.05% (95%CI: -2.10 to -2.00), whereas Europe and Central Asia observed an uptrend with an AAPC of 0.72% (95%CI: 0.69 to 0.74). Latin America and the Caribbean also showed an uptrend with an AAPC of 0.06% (95%CI: 0.02 to 0.11). In the Middle East and North Africa, the AAPC was non-significant at 0.02% (95%CI: -0.09 to 0.12). North America, in contrast, displayed a significant upward trend with an AAPC of 2.63% (95%CI: 2.57 to 2.67). South Asia (AAPC -0.22%, 95%CI: -0.26 to -0.16) and Sub-Saharan Africa (AAPC -0.14%, 95%CI: -0.15 to -0.12) trends significantly declined over the study period. CONCLUSION: Our study reports disparities in Hepatitis C-related HCC mortality between 1999 to 2019, both regionally and between genders. While East Asia and the Pacific regions showed a promising decline in mortality, North America has experienced a concerning rise in mortality. These regional variations highlight the need for healthcare policymakers and practitioners to tailor public health strategies and interventions. The data serves as a call to action, particularly for regions where mortality rates are not improving, emphasizing the necessity for a nuanced, region-specific approach to combat the global challenge of HCC secondary to Hepatitis C.

Impact of metabolic dysfunction-associated steatotic liver disease on COVID-19 hospitalizations: A propensity-matched analysis of the United States.

BACKGROUND: Metabolic dysfunction-associated steatotic liver disease (MASLD), formally known as nonalcoholic fatty liver disease, is the most common chronic liver disease in the United States. Patients with MASLD have been reported to be at a higher risk of developing severe coronavirus disease 2019 (COVID-19) and death. However, most studies are single-center studies, and nationwide data in the United States is lacking. AIM: To study the influence of MASLD on COVID-19 hospitalizations during the initial phase of the pandemic. METHODS: We retrospectively analyzed the 2020 National Inpatient Sample (NIS) database to identify primary COVID-19 hospitalizations based on an underlying diagnosis of MASLD. A matched comparison cohort of COVID-19 hospitalizations without MASLD was identified from NIS after 1: N propensity score matching based on gender, race, and comorbidities, including hypertension, heart failure, diabetes, and cirrhosis. The primary outcomes included inpatient mortality, length of stay, and hospitalization costs. Secondary outcomes included the prevalence of systemic complications. RESULTS: A total of 2210 hospitalizations with MASLD were matched to 2210 hospitalizations without MASLD, with a good comorbidity balance. Overall, there was a higher prevalence of severe disease with more intensive care unit admissions (9.5% vs 7.2%, P = 0.007), mechanical ventilation (7.2% vs 5.7%, P = 0.03), and septic shock (5.2% vs 2.7%, P <0.001) in the MASLD cohort than in the non-MASLD cohort. However, there was no difference in mortality (8.6% vs 10%, P = 0.49), length of stay (5 d vs 5 d, P = 0.25), and hospitalization costs (42081.5 $ vs 38614$, P = 0.15) between the MASLD and non-MASLD cohorts. CONCLUSION: The presence of MAFLD with or without liver cirrhosis was not associated with increased mortality in COVID-19 hospitalizations; however, there was an increased incidence of severe COVID-19 infection. This data (2020) predates the availability of COVID-19 vaccines, and many MASLD patients have since been vaccinated. It will be interesting to see if these trends are present in the subsequent years of the pandemic.

Impact of COVID-19 on liver transplant recipients: A nationwide cohort study evaluating hospitalization, transplant rejection, and inpatient mortality.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has posed a major public health concern worldwide. Patients with comorbid conditions are at risk of adverse outcomes following COVID-19. Solid organ transplant recipients with concurrent immunosuppression and comorbidities are more susceptible to a severe COVID-19 infection. It could lead to higher rates of inpatient complications and mortality in this patient population. However, studies on COVID-19 outcomes in liver transplant (LT) recipients have yielded inconsistent findings. AIM: To evaluate the impact of the COVID-19 pandemic on hospital-related outcomes among LT recipients in the United States. METHODS: We conducted a retrospective cohort study using the 2019-2020 National Inpatient Sample database. Patients with primary LT hospitalizations and a secondary COVID-19 diagnosis were identified using the International Classification of Diseases, Tenth Revision coding system. The primary outcomes included trends in LT hospitalizations before and during the COVID-19 pandemic. Secondary outcomes included comparative trends in inpatient mortality and transplant rejection in LT recipients. RESULTS: A total of 15720 hospitalized LT recipients were included. Approximately 0.8% of patients had a secondary diagnosis of COVID-19 infection. In both cohorts, the median admission age was 57 years. The linear trends for LT hospitalizations did not differ significantly before and during the pandemic (P = 0.84). The frequency of in-hospital mortality for LT recipients increased from 1.7% to 4.4% between January 2019 and December 2020. Compared to the pre-pandemic period, a higher association was noted between LT recipients and in-hospital mortality during the pandemic, with an odds ratio (OR) of 1.69 [95% confidence interval (CI): 1.55-1.84), P < 0.001]. The frequency of transplant rejections among hospitalized LT recipients increased from 0.2% to 3.6% between January 2019 and December 2020. LT hospitalizations during the COVID-19 pandemic had a higher association with transplant rejection than before the pandemic [OR: 1.53 (95%CI: 1.26-1.85), P < 0.001]. CONCLUSION: The hospitalization rates for LT recipients were comparable before and during the pandemic. Inpatient mortality and transplant rejection rates for hospitalized LT recipients were increased during the COVID-19 pandemic.

Mechanistically based blood proteomic markers in the TGF-ß pathway stratify risk of hepatocellular cancer in patients with cirrhosis.

Hepatocellular carcinoma (HCC) is the third leading cause of death from cancer worldwide but is often diagnosed at an advanced incurable stage. Yet, despite the urgent need for blood-based biomarkers for early detection, few studies capture ongoing biology to identify risk-stratifying biomarkers. We address this gap using the TGF-ß pathway because of its biological role in liver disease and cancer, established through rigorous animal models and human studies. Using machine learning methods with blood levels of 108 proteomic markers in the TGF-ß family, we found a pattern that differentiates HCC from non-HCC in a cohort of 216 patients with cirrhosis, which we refer to as TGF-ß based Protein Markers for Early Detection of HCC (TPEARLE) comprising 31 markers. Notably, 20 of the patients with cirrhosis alone presented an HCC-like pattern, suggesting that they may be a group with as yet undetected HCC or at high risk for developing HCC. In addition, we found two other biologically relevant markers, Myostatin and Pyruvate Kinase M2 (PKM2), which were significantly associated with HCC. We tested these for risk stratification of HCC in multivariable models adjusted for demographic and clinical variables, as well as batch and site. These markers reflect ongoing biology in the liver. They potentially indicate the presence of HCC early in its evolution and before it is manifest as a detectable lesion, thereby providing a set of markers that may be able to stratify risk for HCC.

Comparison of the management of gastric variceal bleeding techniques.

Background and Aim: Managing gastric variceal (GV) hemorrhage is more complicated than managing esophageal variceal (EV) bleeding, resulting in significantly higher morbidity and mortality. We aim to compare the outcomes of endoscopic variceal ligation (EVL), transhepatic intrahepatic portosystemic shunt (TIPS), and balloon-occluded retrograde transvenous obliteration (BRTO) in the management of GV bleeding. Methods: We utilized the National Inpatient Sample (NIS) database from January 2016 to December 2019 to include adult patients with GV hemorrhage. Results: Our study identified 7160 hospitalizations with a primary diagnosis of GV hemorrhage who underwent the interventions of interest. EVL was performed in 69.83%, TIPS in 8.72%, and BRTO in 4.88%. Patients with liver cirrhosis had a higher frequency of undergoing BRTO (68.6%), followed by TIPS (64.0%) and esophagogastroduodenoscopy (EGD) + TIPS (63.7%) (P < 0.001). Patients with cirrhosis secondary to alcoholism had a higher prevalence of TIPS (62.4%), followed by EGD + TIPS (69.4%) and BRTO (52.9%) (P < 0.001). Overall, the inpatient mortality was 6.5%. Overall inpatient mortality was highest in the TIPS cohort (8.8%), followed by BRTO (7.1%), EGD + TIPS (6.5%), EVL (6.2%), and EGD + BRTO (2.8%) (P < 0.001); However, the Kaplan-Meier graph showed endoscopy with BRTO had the most favorable 30-day survival, trailed by TIPS alone and BRTO alone. Conclusion: EVL remains a prominent therapeutic strategy. Remarkably, the combination of endoscopy with BRTO shows promising 30-day survival outcomes. Considering these observations, although EVL holds its primacy, it is essential to further explore the potential benefits of combined therapies in larger studies to ascertain the best treatment strategies.