Magnetic Resonance Elastography and Other Magnetic Resonance Imaging Techniques in Chronic Liver Disease: Current Status and Future Directions

Development and validation of a predictive nomogram for the risk of MAFLD in postmenopausal women

Background and aim

Metabolic-associated fatty liver disease (MAFLD) has gradually become one of the main health concerns regarding liver diseases. Postmenopausal women represent a high-risk group for MAFLD; therefore, it is of great importance to identify and intervene with patients at risk at an early stage. This study established a predictive nomogram model of MAFLD in postmenopausal women and to enhance the clinical utility of the new model, the researchers limited variables to simple clinical and laboratory indicators that are readily obtainable.

Methods

Data of 942 postmenopausal women from January 2023 to October 2023 were retrospectively collected and divided into two groups according to the collection time: the training group (676 cases) and the validation group (226 cases). Significant indicators independently related to MAFLD were identified through univariate logistic regression and stepwise regression, and the MAFLD prediction nomogram was established. The C-index and calibration curve were used to quantify the nomogram performance, and the model was evaluated by measuring the area under the receiver operating characteristic curve (AUC), calibration curve, and decision curve analysis (DCA).

Results

Of 37 variables, 11 predictors were identified, including occupation (worker), body mass index, waist-to-hip ratio, number of abortions, anxiety, hypertension, hyperlipidemia, diabetes, hyperuricemia, and diet (meat and processed meat). The C-index of the training group predicting the related risk factors was 0.827 (95% confidence interval [CI] 0.794-0.860). The C-index of the validation group was 0.787 (95% CI 0.728-0.846). Calibration curves 1 and 2 (BS1000 times) were close to the diagonal, showing a good agreement between the predicted probability and the actual incidence in the two groups. The AUC of the training group was 0.827, the sensitivity was 0.784, and the specificity was 0.735. The AUC of the validation group was 0.787, the sensitivity was 0.674, and the specificity was 0.772. The DCA curve showed that the nomogram had a good net benefit in predicting MAFLD in postmenopausal women.

Conclusions

A predictive nomogram for MAFLD in postmenopausal women was established and verified, which can assist clinicians in evaluating the risk of MAFLD at an early stage.

Utility and impact of magnetic resonance elastography in the clinical course and management of chronic liver disease

We aimed to characterize scenarios where magnetic resonance elastography (MRE) of the liver was ordered and its impact on clinical course and management. 96 consecutive MRE examinations and subsequent encounters over 14 months were reviewed. Indication for MRE of the liver and subsequent management were abstracted from the medical record. In all cases, non-invasive assessment of liver fibrosis was the primary indication and at least one additional rationale was noted. There was a significant decrease in recommendations to undergo liver biopsy after MRE. Additionally, a greater percentage of those recommended to undergo biopsy completed the procedure after discussion of the results. Given the significant cost and rare but serious risks of liver biopsy, MRE of the liver provides an attractive, safer alternative that may have a comparable impact on management, or select cases where biopsy is essential to guide management. We demonstrate the versatility of MRE in real-world hepatology practice, including its utility as a non-invasive surrogate for liver biopsy.

Development and Validation of a Nomogram for Prediction of the Risk of MAFLD in an Overweight and Obese Population

BACKGROUND AND AIMS

Metabolic associated fatty liver disease (MAFLD) is a serious condition, and a simple method is needed for practitioners to identify patients with the disease and have a high risk of disease progression.

METHODS

We developed and validated a nomogram for fatty liver disease and reclassified the risk factors for MAFLD. The development cohort had 335 patients who received bioelectrical impedance analysis and liver ultrasound attenuation measurements at Shenzhen People's Hospital between September 2020 and June 2021. The validation cohort had 200 patients from other hospitals who received the same evaluation. A random forest procedure and binary logistic analysis were used to screen for risk factors, establish a fatty liver disease predictive model, and forecast the risk of MAFLD. The performance of the nomogram was evaluated by measurement of discrimination, calibration, and clinical usefulness.

RESULTS

The nomogram provided good predictions in a model that included body mass index (BMI) and waist circumference. The areas under the curve of the nomogram were 0.793 in the development cohort and 0.774 in the validation cohort. The nomogram performed well for calibration, category-free net reclassification improvement, and integrated discrimination improvement. Decision curve analysis indicated the nomogram performed better than BMI for predicting net outcome.

CONCLUSIONS

The nomogram was an effective screening tool for fatty liver disease, and for those overweight individuals, may help physicians make appropriate decisions regarding treatment of MAFLD.

Preoperative evaluation of liver regeneration following hepatectomy in hepatocellular carcinoma using magnetic resonance elastography

BACKGROUND

For patients with hepatocellular carcinoma (HCC) undergoing hepatectomy, insufficient remnant liver regenerative capacity can lead to liver failure. The aim of this study was to evaluate the potential role of magnetic resonance elastography (MRE) for the preoperative prediction of liver regeneration in patients with HCC after partial hepatectomy (PH).

METHODS

A total of 54 patients with HCC undergoing MRE prior to PH were retrospectively included. The total functional liver, volume of preoperative future liver remnant (LVpre), and volume of postoperative liver remnant (LVpost), respectively, were measured, and the regeneration index (RI) and parenchymal hepatic resection rate (PHRR) were manually calculated. Univariate and multivariate logistic regression analyses were conducted to identify factors associated with a high RI, and receiver operating characteristic (ROC) curves were employed to evaluate the diagnostic performance of the liver stiffness (LS) values. Patients were classified into three subgroups based on the value of PHRR: low PHRR (<30%), intermediate PHRR (30-50%), and high PHRR (>50%). Subsequently, Spearman correlation analysis was used to investigate the relationship between LS values and RI in the subgroups.

RESULTS

Multivariable analysis revealed a low LS value was associated with greater odds of a high RI [odds ratio (OR), 0.049; 95% confidence interval (CI): 0.002 to 0.980]. An optimal cutoff value of 3.30 kPa was used to divide all patients into a low RI group and a high RI group with an area under the curve (AUC) value of 0.882 (95% CI: 0.767 to 0.996). A significant negative relationship between RI and LS values (r=-0.799; P<0.001) was observed in the intermediate PHRR subgroup.

CONCLUSIONS

The LS values based on MRE may serve as a potential preoperative predictor of liver regeneration for patients with HCC undergoing PH.

Multiparametric magnetic resonance imaging/magnetic resonance elastography assesses progression and regression of steatosis, inflammation, and fibrosis in alcohol-associated liver disease

BACKGROUND

Magnetic resonance imaging (MRI) and MRI-based elastography (MRE) are the most promising noninvasive techniques in assessing liver diseases. The purpose of this study was to evaluate an advanced multiparametric imaging method for staging disease and assessing treatment response in realistic preclinical alcohol-associated liver disease (ALD).

METHODS

We utilized four different preclinical mouse models in our study: Model 1-mice were fed a fast-food diet and fructose water for 48 weeks to induce nonalcoholic fatty liver disease; Model 2-mice were fed chronic-binge ethanol (EtOH) for 10 days or 8 weeks to induce liver steatosis/inflammation. Two groups of mice were treated with interleukin-22 at different time points to induce disease regression; Model 3-mice were administered CCl4 for 2 to 4 weeks to establish liver fibrosis followed by 2 or 4 weeks of recovery; and Model 4-mice were administered EtOH plus CCl4 for 12 weeks. Mouse liver imaging biomarkers including proton density fat fraction (PDFF), liver stiffness (LS), loss modulus (LM), and damping ratio (DR) were assessed. Liver and serum samples were obtained for histologic and biochemical analyses. Ordinal logistic regression and generalized linear regression analyses were used to model the severity of steatosis, inflammation, and fibrosis, and to assess the regression of these conditions.

RESULTS

Multiparametric models with combinations of biomarkers (LS, LM, DR, and PDFF) used noninvasively to predict the histologic severity and regression of steatosis, inflammation, and fibrosis were highly accurate (area under the curve > 0.84 for all). A three-parameter model that incorporates LS, DR, and ALT predicted histologic fibrosis progression (r = 0.84, p < 0.0001) and regression (r = 0.79, p < 0.0001) as measured by collagen content in livers.

CONCLUSION

This preclinical study provides evidence that multiparametric MRI/MRE can be used noninvasively to assess disease severity and monitor treatment response in ALD.

Diagnosis and Staging of Pediatric Non-Alcoholic Fatty Liver Disease: Is Classical Ultrasound the Answer?

The increased prevalence of non-alcoholic fatty liver disease (NAFLD) requires special attention in pediatric patients, as it manifests in them in a more severe and progressive way compared to adults. The implementation of the appropriate therapeutic interventions is determinant of the attempts to treat it. For that purpose, early diagnosis and staging of the disease is essential. The purpose of this review was to find and reveal the most appropriate diagnostic strategies and tools for diagnosis and staging of pediatric NAFLD/NASH based on their accuracy, safety and effectiveness. The methodology followed was that of the literature review. Particular emphasis was put on the recent bibliography. A comparative study of published articles about the diagnosis and management of pediatric NAFLD/NASH was also performed. In terms of diagnosis, the findings converged on the use of classical ultrasound. Ultrasound presented average sensitivity and specificity for diagnosing the disease in children, while in the adult population, sensitivity and specificity were significantly higher. Proton density fat fraction magnetic resonance imaging has been increasingly used for the diagnosis of steatosis in pediatric patients. Elastography is an effective tool for staging liver fibrosis and discriminating NASH from NAFLD in children. Even though liver biopsy is the gold standard, especially for NASH, it should be avoided for pediatric patients. Biochemical tests are less specific and less sensitive for the diagnosis of NAFLD, and some of them are of high cost. It seems that diagnostic imaging should be a first-line tool for the staging and monitoring pediatric NAFLD/NASH in order for appropriate interventions to be implanted in a timely way.

Evaluation of Renal Fibrosis by Mapping Histology and Magnetic Resonance Imaging

Background

Renal fibrosis is a key driver of progression in chronic kidney disease (CKD). Recent advances in diagnostic imaging techniques have shown promising results for the noninvasive assessment of renal fibrosis. However, the specificity and accuracy of these techniques are controversial because they indirectly assess renal fibrosis. This limits fibrosis assessment by imaging in CKD for clinical practice. To validate magnetic resonance imaging (MRI) assessment for fibrosis, we derived representative models by mapping histology-proven renal fibrosis and imaging in CKD.

Methods

Ninety-seven adult Chinese CKD participants with histology were studied. The kidney cortex interstitial extracellular matrix volume was calculated by the Aperio ScanScope system using Masson's trichrome slices. The kidney cortex microcirculation was quantitatively assessed by peritubular capillary density using CD34 staining. The imaging techniques included intravoxel incoherent motion diffusion-weighted imaging and magnetic resonance elastography (MRE) imaging. Relevant analyses were performed to evaluate the correlations between MRI parameters and histology variables. Multiple linear regression models were used to describe the relationships between a response variable and other variables. The best-fit lines, which minimize the sum of squared residuals of the multiple linear regression models, were generated.

Results

MRE values were negatively associated with the interstitial extracellular matrix volume (Rho = -0.397, p < 0.001). The best mapping model of extracellular matrix volume with the MRE value and estimated glomerular filtration rate (eGFR) we obtained was as follows: Interstitial extracellular matrix volume = 218.504 - 14.651 × In(MRE) - 18.499 × In(eGFR). DWI-fraction values were positively associated with peritubular capillary density (Rho = 0.472, p < 0.001). The best mapping model of peritubular capillary density with DWI-fraction value and eGFR was as follows: Peritubular capillaries density = 17.914 + 9.403 × (DWI - fraction) + 0.112 × (eGFR).

Conclusions

The study provides histological evidence to support that MRI can effectively evaluate fibrosis in the kidney. These findings picture the graphs of the mapping model from imaging and eGFR into fibrosis, which has significant value for clinical implementation.

Comparison of MR-PWI quantitative and semi-quantitative parameters for the evaluation of liver fibrosis

Background

To evaluate different stages of liver fibrosis in cynomolgus monkeys by comparing magnetic resonance-perfusion weighted imaging (MR-PWI) quantitative and semi-quantitative parameters, and confirm the best detection indicators for diagnosis of liver fibrosis.

Methods

A liver fibrosis model of different stages (S0–S4) was established in cynomolgus monkeys. The changes in MR-PWI quantitative and semi-quantitative parameters with the progression of liver fibrosis were investigated.

Results

MR-PWI quantitative parameters gradually decreased with the progression of liver fibrosis. Hepatic arterial perfusion index (HPI) was found to increase with the progression of liver fibrosis and significant differences of HPI between each group were observed. There was a highly positive correlation between HPI and the stages of liver fibrosis. Receiver operating characteristic (ROC) curve analysis showed that HPI had the highest efficacy of the MR-PWI quantitative parameters for the diagnosis of liver fibrosis. The MR-PW semi-quantitative parameters gradually reduced with the progression of liver fibrosis, and the differences were statistically significant between stages S3–S4 and S0–S2. Time to peak (TPP) gradually extended and showed a positive correlation with the stages of liver fibrosis. TTP had the highest efficacy of the semi-quantitative parameters for diagnosis of liver fibrosis.

Conclusions

Both the MR-PWI quantitative and semi-quantitative parameters of the liver fibrosis model in cynomolgus monkeys varied at different stages of liver fibrosis, and HPI and TTP were the best detection indices for quantitative and semi-quantitative evaluation of liver fibrosis, respectively.

A gadofullerene based liver-specific MRI contrast agent for an early diagnosis of orthotopic hepatocellular carcinoma

Hepatocellular carcinoma has become one of the most prevalent cancers, with a high mortality rate. Accurate diagnosis at an earlier stage is regarded as an effective measure to reduce the disease-related mortality of liver cancer. Magnetic resonance imaging (MRI) as a non-invasive checking mode has become a powerful tool in medical diagnosis. However, MRI contrast agents for liver-specific imaging either have some side effects or the imaging effect is not ideal. Thus, development of more efficient and security MRI contrast agents for the early diagnosis of hepatocellular carcinoma is urgent. Herein, a kind of water-soluble gadofullerene nanoparticle (GFNP) with high efficiency and security has been successfully used to achieve in situ liver cancer imaging. By comparing GFNPs with different functional groups, Gd@C82 modified by a hydroxyl group (GF-OH) presents the highest contrast efficiency both in vitro and in vivo. Notably, the smallest tumor with a diameter of only 0.5 mm could be clearly observed by GF-OH using MRI. Moreover, the imaging window of GF-OH is more than 3-6 hours. In addition, GF-OH can be mostly excreted from the living body and causes no serious toxicity. These results demonstrate that GF-OH is a safe, efficient MRI contrast agent for the diagnosis of early orthotopic hepatocellular carcinoma.

Magnetic resonance imaging for the assessment of pathological hepatic findings in nonalcoholic fatty liver disease

The prevalence of nonalcoholic fatty liver disease (NAFLD) is expected to increase because of the current epidemics of obesity and diabetes, and NAFLD has become a major cause of chronic liver disease worldwide. Liver fibrosis is associated with poor long-term outcomes in patients with NAFLD. Additionally, increased mortality and liver-related complications are primarily seen in patients with nonalcoholic steatohepatitis (NASH); however, nonalcoholic fatty liver (NAFL) is believed to be benign and non-progressive. Therefore, distinguishing between NASH and NAFL is clinically important. Liver biopsy is the gold standard method for the staging of liver fibrosis and distinguishing between NASH and NAFL. Unfortunately, liver biopsy is an invasive and expensive procedure. Therefore, noninvasive methods, to replace biopsy, are urgently needed for the staging of liver fibrosis and diagnosing NASH. In this review, we discuss the recent studies on magnetic resonance imaging (MRI), including magnetic resonance elastography, proton density fat fraction measurement, and multiparametric MRI (mpMRI) that can be used in the assessment of NASH components such as liver fibrosis, steatosis, and liver injury including inflammation and ballooning.

Advances in Imaging of Diffuse Parenchymal Liver Disease

There are >1.5 billion people with chronic liver disease worldwide, causing liver diseases to be a significant global health issue. Diffuse parenchymal liver diseases, including hepatic steatosis, fibrosis, metabolic diseases, and hepatitis cause chronic liver injury and may progress to fibrosis and eventually hepatocellular carcinoma. As early diagnosis and treatment of these diseases impact the progression and outcome, the need for assessment of the liver parenchyma has increased. While the current gold standard for evaluation of the hepatic parenchymal tissue, biopsy has disadvantages and limitations. Consequently, noninvasive methods have been developed based on serum biomarkers and imaging techniques. Conventional imaging modalities such as ultrasound, computed tomography scan, and magnetic resonance imaging provide noninvasive options for assessment of liver tissue. However, several recent advances in liver imaging techniques have been introduced. This review article focuses on the current status of imaging methods for diffuse parenchymal liver diseases assessment including their diagnostic accuracy, advantages and disadvantages, and comparison between different techniques.

Multiparametric MRI in Patients With Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is a common cause of chronic liver disease in the world, affecting more than 25% of the adult population. NAFLD covers a spectrum including simple steatosis, in which lipid accumulation in hepatocytes is the predominant histological characteristic, and nonalcoholic steatohepatitis (NASH), which is characterized by additional hepatic inflammation with or without fibrosis. Liver biopsy is currently the reference standard to discriminate between hepatic steatosis and steatohepatitis. Since liver biopsy has several disadvantages, noninvasive diagnostic methods with high sensitivity and specificity are desirable for the analysis of NAFLD. Improvements in magnetic resonance imaging (MRI) technology are continuously being implemented in clinical practice, specifically multiparametric MRI methods such as proton density fat‐fraction (PDFF), T₂*, and T₁ mapping, along with MR elastography. Multiparametric imaging of the liver has a promising role in the clinical management of NAFLD with quantification of fat content, iron load, and fibrosis, which are features in NAFLD. In the present article, we review the utility and limitations of multiparametric quantitative imaging of the liver for diagnosis and management of patients with NAFLD.

Level of Evidence

5.

Technical Efficacy Stage

3.

Elastography Techniques for the Assessment of Liver Fibrosis in Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is expected to increase in prevalence because of the ongoing epidemics of obesity and diabetes, and it has become a major cause of chronic liver disease worldwide. Liver fibrosis is associated with long-term outcomes in patients with NAFLD. Liver biopsy is recommended as the gold standard method for the staging of liver fibrosis. However, it has several problems. Therefore, simple and noninvasive methods for the diagnosis and staging of liver fibrosis are urgently needed in place of biopsy. This review discusses recent studies of elastography techniques (vibration-controlled transient elastography, point shear wave elastography, two-dimensional shear wave elastography, and magnetic resonance elastography) that can be used for the assessment of liver fibrosis in patients with NAFLD.

Segmental Liver Stiffness Evaluated with Magnetic Resonance Elastography Is Responsive to Endovascular Intervention in Patients with Budd-Chiari Syndrome

OBJECTIVE

To assess segmental liver stiffness (LS) with MRI before and after endovascular intervention in patients with Budd-Chiari syndrome (BCS).

MATERIALS AND METHODS

Twenty-three patients (13 males and 10 females; mean age, 42.6 ± 12.6 years; age range, 31-56 years) with BCS as a primary liver disease were recruited for this study. Two consecutive magnetic resonance elastography (MRE) examinations were performed before the endovascular treatment. Fifteen patients who underwent endovascular intervention treatment also had follow-up MRE scans within three days after the procedure. LS was measured in three liver segments: the right posterior, right anterior, and left medial segments. Inter-reader and inter-exam repeatability were analyzed with intraclass correlation coefficients (ICCs) and Bland-Altman analysis. Segmental LS and clinical characteristics before and after the intervention were also compared.

RESULTS

Within three days of the endovascular intervention, all three segmental LS values decreased: LS of the right posterior segment = 7.23 ± 0.88 kPa (before) vs. 4.94 ± 0.84 kPa (after), LS of the right anterior segment = 7.30 ± 1.06 kPa (before) vs. 4.77 ± 0.85 kPa (after), and LS of the left medial segment = 7.22 ± 0.87 kPa (before) vs. 4.87 ± 0.72 kPa (after) (all p = 0.001). There was a significant correlation between LS changes and venous pressure gradient changes before and after treatments (r = 0.651, p = 0.009). The clinical manifestations of all 15 patients significantly improved after therapy. The MRE repeatability was excellent, with insignificant variations (inter-reader, ICC = 0.839-0.943: inter-examination, ICC = 0.765-0.869). Bland-Altman analysis confirmed excellent agreement (limits of agreement, 13.4-19.4%).

CONCLUSION

Segmental LS measured by MRE is a promising repeatable quantitative biomarker for monitoring the treatment response to minimally invasive endovascular intervention in patients with BCS.

Functional MRI as a Tool for Evaluating Interstitial Fibrosis and Prognosis in Kidney Disease

Background

Kidney fibrosis is a key driver of progression of kidney diseases. Renal biopsies remain the gold-standard approach to specifically diagnose and stage renal fibrosis at present. However, there is a lack of multi-dimensional pictures showing renal function, histology, and imaging of the fibrotic kidney.

Summary

Magnetic resonance imaging (MRI) strategies have been rapidly evolving during the past couple of decades, especially driven by advances in technology. Recently, several pioneer and remarkable studies demonstrated that advanced functional MRI (fMRI) tools could be useful for the evaluation of kidney fibrosis and progression, which provides more opportunities to benefit from the significant value of fMRI tools for clinical implementation.

Key Messages

fMRI will be a novel approach to evaluate interstitial fibrosis and prognosis in kidney disease.

CAPN2 acts as an indicator of hepatitis B virus to induce hepatic fibrosis

This study is aimed to investigate whether calpain 2 (CAPN2) serves as an indicator of the hepatitis B virus (HBV) to induce hepatic fibrosis. Differentially-expressed genes (DEGs) in HBV-induced hepatic fibrosis and normal liver tissues were analyzed, and signal pathway which was analyzed by the Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis using DEGs. Next, the gene-related network map was constructed using the Search Tool for the Retrieval of Interacting Genes. Moreover, CAPN2 protein expression, level of hepatic fibrosis, CAPN2 messenger RNA level, and protein levels of CAPN2, a-SAM, COL3A1, COL1A1, and MAPK1 were determined using Immunohistochemistry (IHC), hematoxylin and eosin, RT-qPCR, and western blot (WB), respectively. There were 420 DEGs screened in HBV-induced hepatic fibrosis and normal liver tissues, among which, 373 were significantly upregulated and 47 were obviously downregulated. KEGG analysis showed that the upregulated DEGs were mainly concentrated in extracellular matrix-receptor interaction, protein digestion, and absorption signaling pathways. The network diagram analysis showed that the DEGs, such as CAPN2, ITGAV, and CCR2, play the key role in the DEG network map, and CAPN2 related to hepatic fibrosis via MAPK1. The increased CAPN2 expression and obvious hepatic fibrosis was displayed in the HBV-induced hepatic fibrosis tissues. In addition, HBV could induce CAPN2 expression, and the interference of CAPN2 could inhibit the expression of hepatic fibrosis markers, including a-SAM, COL3A1, COL1A1, and MAPK1. CAPN2 is regarded as a biomarker of hepatic fibrosis induced by HBV.

Management of Recurrent and De Novo NAFLD/NASH After Liver Transplantation

Nonalcoholic steatohepatitis (NASH) is a growing indication for liver transplant whether the primary or secondary cause of liver disease, and it is expected to be the leading indication in the years to come. Nonalcoholic steatohepatitis recurs after transplant but the impact of the recurrence on allograft and patient outcomes is unclear. A group of multidisciplinary transplant practice providers convened at the International Liver Transplantation Society NASH consensus conference with the purpose of determining the current knowledge and future directions for understanding the recurrence rates, risk and management of NASH in the transplant allograft. Specific questions relating to posttransplant NASH were proposed and reviewed in detail with recommendations on future actions to fill the knowledge gaps.

Quantitative magnetic resonance imaging evaluation of hepatic fat content with iron deposition: will it be disturbed?

Objective

To explore noninvasive assessment of liver fat content with iron deposition using magnetic resonance (MR) quantitative technology.

Methods

A water–fat phantom with iron deposition containing 63 vials with predetermined fat percentages and iron concentrations was constructed. Thirty-three patients underwent fat quantitative MR examinations. The fat fraction (FF) was determined by three Dixon techniques. Pathological evaluation findings and the steatosis area rate (SAR) were used as the gold standards.

Results

FF_IOP and FF_LAVA-Flex significantly differed from FF_TEST for iron concentrations of 1 to 30 µg/mL and fat components of 10% to 80%. Using the three Dixon techniques, FF_IOP was 15.76% ± 6.98%, FF_LAVA-Flex was 16.71% ± 6.77%, and FF_{IDEAL IQ} was 13.18% ± 6.42% in patients without liver cirrhosis; these values in patients with liver cirrhosis were 20.35% ± 6.11%, 20.89% ± 8.49%, and 12.86% ± 4.00%, respectively. The SAR in patients without and with liver cirrhosis was 11.31% ± 5.89% and 9.84% ± 4.17%, respectively. There were significant positive correlations between FF_{IDEAL IQ} and SAR with or without liver cirrhosis.

Conclusion

Iron deposition must be considered when using quantitative MR techniques to evaluate the hepatic fat content. Compared with the IOP and LAVA-Flex techniques, the IDEAL IQ technique has more stability and accuracy in measurement of the hepatic fat content, free from iron deposition.

Gd-EOB-DTPA DCE-MRI biomarkers in a rabbit model of liver fibrosis

The purpose of this study was to investigate the correlations between Gd-EOB-DTPA DCE-MRI biomarkers and histopathologic biomarkers of liver fibrosis progression in a rabbit model of liver fibrosis. Thirty-Six New Zealand white rabbits were randomly divided into control (n = 6) and liver fibrosis group (n = 30). Each rabbit in the liver fibrosis group received a weekly subcutaneous injection in the back comprising 50% carbon tetrachloride (CCl₄) in oily solution. Control rabbits received subcutaneous injections with the same amount of normal saline solution instead. MR imaging was performed in control and fibrotic rabbits were conducted by MRI at week 0 (n = 36). The fibrotic rabbits were performed MR imaging on 6 weeks, 9 weeks, and 12 weeks after modeling of fibrosis. Before each MRI, peripheral blood was collected, and several biochemical testes are performed. The thirty-four rabbits completed this study. They were then divided into three subgroups according to fibrotic stage: no fibrosis (F0, n = 12), mild fibrosis (F1+F2, n = 14), and advanced fibrosis (F3+F4, n = 8). DCE-MRI measurements show increasing K^trans and V_e while decreasing iACU90 with increasing fibrosis stage. The significant correlations were observed between mean K^trans, V_e, iACU90 and percentage of the animal with mild liver fibrosis. For blood biomarkers, there were significant differences between F0 and F1+F2, and between F0 and F3+F4 in the serum levels of ALT (all P < 0.05), and TB (F0 vs. F1+F2, P = 0.004), while no differences were found between F1+F2 group and F3+F4 group (all P > 0.05). There were significant differences between F0 and F1+F2 (P = 0.02). Gd-EOB-DTPA DCE-MRI is a promising method for the noninvasive diagnosis and staging of liver fibrosis. Future studies to evaluate the effectiveness of these techniques in patients with liver fibrosis are warranted.

Imaging of Hepatic Fibrosis

PURPOSE OF REVIEW

The purpose of this review is to discuss the current imaging techniques for non-invasive assessment of liver fibrosis (LF).

RECENT FINDINGS

Elastography-based techniques are the most widely used imaging methods for the evaluation of LF. Currently, MR elastography (MRE) is the most accurate non-invasive method for detection and staging of LF. Ultrasound-based vibration-controlled transient elastography (VCTE) is the most widely used as it can be easily performed at the point of care but has technical limitations especially in the obese. Innovations and technical improvements continue to evolve in elastography for improving accuracy and avoiding misinterpretation from confounding factors. Other imaging methods including diffusion-weighted imaging (DWI), hepatocellular contrast-enhanced (HCE) MRI, T1 relaxometry, T1ρ imaging, textural analysis, liver surface nodularity, susceptibility-weighted imaging, and perfusion imaging are promising but need further evaluation and clinical validation. MRE is the most accurate imaging technique for assessment of LF.

Liver fibrosis detection and staging: a comparative study of T1ρ MR imaging and 2D real-time shear-wave elastography

Purpose

To compare the results of T1ρ MR imaging and 2D real-time shear-wave elastography (SWE) for liver fibrosis detection and staging.

Methods

Twenty-nine rabbit models of CCl₄-induced liver fibrosis were established and six untreated rabbits served as controls. T1ρ MR imaging and 2D real-time SWE examination were performed at 2, 4, 6, 8, 10, and 12 weeks. T1ρ values and liver stiffness (LS) values were measured. Fibrosis was staged according to the METAVIR scoring system. Correlation test was performed among T1ρ values, LS values, and fibrosis stage. Receiver operating characteristic (ROC) analysis was performed for assessing diagnostic performance of T1ρ and SWE in detection of no fibrosis (F0), substantial fibrosis (≥ F2), severe fibrosis (≥ F3), and cirrhosis (F4).

Results

There was moderate positive correlation between fibrosis stage and T1ρ values (r = 0.566; 95% CI 0.291–0.754; P < 0.0001), and LS value (r = 0.726; 95% CI 0.521–0.851; P = 0.003). T1ρ values showed moderate positive correlations with LS values [r = 0.693; 95% confidence interval (CI) 0.472–0.832; P < 0.0001]. Areas Under ROC (AUROCs) were 0.861 (95% CI 0.705–0.953) for SWE and 0.856 (95% CI 0.698–0.950) for T1ρ (P = 0.940), 0.906 (95% CI 0.762–0.978) for SWE and 0.849 (95% CI 0.691–0.946) for T1ρ (P = 0.414), 0.870 (95% CI 0.716–0.958) for SWE and 0.799 (95% CI 0.632–0.913) for T1ρ (P = 0.422), and 0.846 (95% CI 0.687–0.944) for SWE and 0.692 (95% CI 0.517–0.835) for T1ρ (P = 0.137), when diagnosing liver fibrosis with ≥ F1, ≥ F2, ≥ F3, and F4, respectively. There was moderate positive correlation between inflammatory activity and T1ρ values (r = 0.520; 95% CI 0.158–0.807; P = 0.013).

Conclusion

T1ρ imaging has potential for liver fibrosis detection and staging with good diagnostic capability similar to that of ultrasonography elastography.

miRNA-221 and miRNA-222 are promising biomarkers for progression of liver fibrosis in HCV Egyptian patients

BACKGROUND

Current methodologies used to determine the progression of hepatic fibrosis rely heavily on liver biopsy, a dangerous and invasive procedure, with semi-subjective analysis of the results of the biopsy. Thus, a new approach is immensely needed for monitoring the progression of liver fibrosis in Hepatitis C virus (HCV) patients.

AIM OF WORK

The purpose of this study was to find highly specific and sensitive miRNA biomarkers that can be used to detect different stages of liver fibrosis.

METHODOLOGY

The study consisted of 42 cases of chronic hepatitis C (CHC) with early-stage fibrosis, 45 cases of CHC with late-stage fibrosis, and 40 healthy subjects with no CHC or fibrosis as controls. Expression patterns of 5 miRNAs (miR-16, miR-146a, miR-214-5p, miR-221, and miR-222) were analyzed in each group using TaqMan real-time PCR.

RESULTS

Serum levels of miRNA-16, miRNA-146a, miRNA-221, and miRNA-222 were all significantly up-regulated in early and late stages of liver fibrosis. miRNA-222 had the highest sensitivity and specificity values in early and late fibrosis. miRNA-221 had the second highest sensitivity and specificity with the late-stage fibrosis group. Furthermore, miRNA-221 showed significant positive correlations with both miRNA-16 and miRNA-146a in the early- and late-stage fibrosis groups, with the early stage having a stronger correlation.

CONCLUSIONS

The results indicated that miRNA-16, miRNA-146a, miRNA-221, and miRNA-222 can be used to detect the presence of liver fibrosis. The high sensitivity and specificity of miRNA-222 and miRNA-221 in late-stage fibrosis indicate promising prognostic biomarkers for HCV-induced liver fibrosis.

Correlating liver stiffness with disease severity scoring system (DS3) values in Gaucher disease type 1 (GD1) patients

Gaucher disease (GD) is an autosomal-recessive lysosomal storage disease caused by a deficiency of the enzyme, glucocerebrocidase, resulting in accumulation of lipid-laden storage cells in multiple organs such as bone marrow, liver, spleen, and lungs. Type 1 Gaucher disease is the most common form of this condition in which the brain and spinal cord (the central nervous system) are not affected. The Gaucher disease severity scoring system (GD-DS3) is typically used to assess disease severity accounting for skeletal, hematologic, and visceral disease. In addition to being time consuming for the clinician to calculate the scores, some of the assessments are subjective and may falsely increase or decrease disease severity. The purpose of this study was to determine if there is a correlation between liver stiffness values obtained from MR elastography (MRE) and the GD-DS3 score. An IRB approved, HIPAA compliant retrospective study was performed. All patients with type 1 GD imaged with MRE between 2011 and 2016 were included in this study. Clinical and imaging data was collected. Two pediatric radiologists analyzed MR images from abdomen and thigh studies independently to determine bone marrow involvement using a semi-quantitative scoring system with one reviewer analyzing a subset of studies to determine inter-observer reliability. The collected data was used to calculate a GD-DS3 score for all patients. GD-DS3 scores were compared with liver MRE stiffness values. Clinical MRE scores were plotted against GD-DS3 severity scores for 31 patients (15 males, 16 females; median age 27years, age range: 4-67years). The median GD-DS3 score was 4 (range: 1-10.1) and median MRE value was 2.43kPa (range: 1.30-5.20kPa). A significant positive correlation was found between MRE and GD-DS3 scores; Pearson's correlation coefficient value of r=0.47, p<0.001 for all scores, r=0.68, p<0.001 for complete scores and r=0.46, p<0.07 for incomplete scores. The inter-observer variation of bone marrow burden showed only fair agreement with a Kappa coefficient of 0.26. There is a significant positive correlation between increasing liver stiffness and increasing composite GD-DS3 scores. This supports the use of MRE, a non-invasive reproducible quantitative test, as both an additional assessment and independent marker for monitoring disease severity and progression in GD.

Radiologic Imaging in Nonalcoholic Fatty Liver Disease and Nonalcoholic Steatohepatitis

The article reviews the multimodality (ultrasound, computed tomography, and magnetic resonance [MR]) imaging appearance of nonalcoholic fatty liver disease (NAFLD) and discusses the radiologic diagnostic criteria as well as the sensitivity and specificity of these imaging methods. The authors review the role of both ultrasound and MR elastography for the diagnosis of fibrosis and for the longitudinal evaluation of patients following therapeutic intervention. Lastly, the authors briefly discuss the screening and diagnosis of hepatocellular carcinoma in patients with NAFLD, as there are special considerations in this population.

Prospects in non-invasive assessment of liver fibrosis: Liquid biopsy as the future gold standard?

Liver fibrosis is the result of persistent liver injury, and is characterized by sustained scar formation and disruption of the normal liver architecture. The extent of fibrosis is considered as an important prognostic factor for the patient outcome, as an absence of (early) treatment can lead to the development of liver cirrhosis and hepatocellular carcinoma. Till date, the most sensitive and specific way for the diagnosis and staging of liver fibrosis remains liver biopsy, an invasive diagnostic tool, which is associated with high costs and discomfort for the patient. Over time, non-invasive scoring systems have been developed, of which the measurements of serum markers and liver stiffness are validated for use in the clinic. These tools lack however the sensitivity and specificity to detect small changes in the progression or regression of both early and late stages of fibrosis. Novel non-invasive diagnostic markers with the potential to overcome these limitations have been developed, but often lack validation in large patient cohorts. In this review, we will summarize novel trends in non-invasive markers of liver fibrosis development and will discuss their (dis-)advantages for use in the clinic.

Imaging biomarkers in liver fibrosis

There is a need for early identification of patients with chronic liver diseases due to their increasing prevalence and morbidity-mortality. The degree of liver fibrosis determines the prognosis and therapeutic options in this population. Liver biopsy represents the reference standard for fibrosis staging. However, given its limitations and complications, different non-invasive methods have been developed recently for the in vivo quantification of fibrosis. Due to their precision and reliability, biomarkers' measurements derived from Ultrasound and Magnetic Resonance stand out. This article reviews the different acquisition techniques and image processing methods currently used in the evaluation of liver fibrosis, focusing on their diagnostic performance, applicability and clinical value. In order to properly interpret their results in the appropriate clinical context, it seems necessary to understand the techniques and their quality parameters, the standardization and validation of the measurement units and the quality control of the methodological problems.

Primary sclerosing cholangitis is protective against nonalcoholic fatty liver disease in inflammatory bowel disease

Nonalcoholic fatty liver disease (NAFLD) occurs with higher prevalence in patients with inflammatory bowel disease (IBD) relative to the general population, and susceptibility is related to the metabolic syndrome, as well as higher prevalence of bowel resection and gut microbiotal factors. Liver complications, including NAFLD and primary sclerosing cholangitis (PSC), contribute to treatment and prognosis of patients with IBD. However, the potential interplay of NAFLD and PSC is not well understood. We retrospectively assessed severity of steatosis and steatohepatitis in liver specimens from 49 patients with IBD only, 44 with IBD and comorbid PSC, and 30 with IBD and PSC after liver transplantation. Patients with IBD had higher prevalence of at least grade 1 steatosis (59%) than IBD and PSC (11%), or IBD and PSC posttransplant (3%) (P < .001). The average severity of steatosis was 25% ± 8% (95% confidence interval) for IBD only, 3% ± 1% for comorbid IBD and PSC, and 1% ± 1% for IBD and PSC posttransplant (P < .001). Steatohepatitis was significantly higher in IBD only (12%) than in IBD and PSC ± transplant (0%) (P = .01). Despite these differences in susceptibility to NAFLD, the 3 populations had statistically indistinguishable average body mass index and total cholesterol and prevalence of hypertension, diabetes, and alcohol use. Multivariate regression modeling revealed body mass index, hypertension, and diabetes as significant correlates to NAFLD severity in all studied populations. In conclusion, patients with comorbid IBD and PSC have significantly less susceptibility to NAFLD than those with IBD alone, despite similar prevalence of major NAFLD risk factors.

Clinical Advancements in the Targeted Therapies against Liver Fibrosis

Hepatic fibrosis, characterized by excessive accumulation of extracellular matrix (ECM) proteins leading to liver dysfunction, is a growing cause of mortality worldwide. Hepatocellular damage owing to liver injury leads to the release of profibrotic factors from infiltrating inflammatory cells that results in the activation of hepatic stellate cells (HSCs). Upon activation, HSCs undergo characteristic morphological and functional changes and are transformed into proliferative and contractile ECM-producing myofibroblasts. Over recent years, a number of therapeutic strategies have been developed to inhibit hepatocyte apoptosis, inflammatory responses, and HSCs proliferation and activation. Preclinical studies have yielded numerous targets for the development of antifibrotic therapies, some of which have entered clinical trials and showed improved therapeutic efficacy and desirable safety profiles. Furthermore, advancements have been made in the development of noninvasive markers and techniques for the accurate disease assessment and therapy responses. Here, we focus on the clinical developments attained in the field of targeted antifibrotics for the treatment of liver fibrosis, for example, small molecule drugs, antibodies, and targeted drug conjugate. We further briefly highlight different noninvasive diagnostic technologies and will provide an overview about different therapeutic targets, clinical trials, endpoints, and translational efforts that have been made to halt or reverse the progression of liver fibrosis.