Use of Liver Imaging and Biopsy in Clinical Practice

Quantitative Assessment of Liver Impairment in Chronic Viral Hepatitis with [99mTc]Tc-Mebrofenin: A Noninvasive Attempt to Stage Viral Hepatitis-Associated Liver Fibrosis

Background and objectives—Chronic viral hepatitis B and C infections are one of the leading causes of chronic liver impairment, resulting in liver fibrosis and liver cirrhosis. An early diagnosis with accurate liver fibrosis staging leads to a proper diagnosis, thus tailoring correct treatment. Both invasive and noninvasive techniques are used in the diagnosis and staging of chronic liver impairment. Those techniques include liver biopsy, multiple serological markers (as either single tests or combined panels), and imaging examinations, such as ultrasound or magnetic resonance elastography. Nuclear medicine probes may also be employed in staging liver fibrosis, although the literature scarcely reports this. The purpose of our study was to investigate whether a dynamic liver scintigraphy with [^99mTc]Tc-mebrofenin has any value in staging or grading chronic liver damage. Materials and Methods—We prospectively enrolled patients with chronic viral hepatitis B and C infection referred for liver biopsy. All patient underwent dynamic liver scintigraphy with 99mTc-mebrofenin prior to liver biopsy. Dynamic liver scintigraphy was performed immediately after intravenous tracer injection for 30 min scanning time. Multiple scintigraphy parameters were calculated (whole liver lobe and focal area time to peak (TTP), 30 min to peak ratio (30/peak), whole lobe and focal area slope index in 350 s (slope_350). Liver biopsy took place shortly after imaging. Results—We found that many dynamic scintigraphic parameters are positively or negatively associated with different stages of liver fibrosis. The main parameters that showed most value are the ratio between 30 min and the peak of the dynamic curve (30/peak_dex (ratio)), and liver clearance corrected for body surface area and liver area (LCL_m²_dm² (%/min/m²/dm²)). Conclusions—Our present study proves that conducting dynamic liver scintigraphies with [^99mTc]Tc-mebrofenin has potential value in staging liver fibrosis. The benefits of this method, including whole liver imaging and direct imaging of the liver function, provide an advantage over presently used quantitative imaging modalities.

A pipeline for automated deep learning liver segmentation (PADLLS) from contrast enhanced CT exams

Multiple studies have created state-of-the-art liver segmentation models using Deep Convolutional Neural Networks (DCNNs) such as the V-net and H-DenseUnet. Oversegmentation however continues to be a problem. We set forth to address these limitations by developing a an automated workflow that leverages the strengths of different DCNN architectures, resulting in a pipeline that enables fully automated liver segmentation. A Pipeline for Automated Deep Learning Liver Segmentation (PADLLS) was developed and implemented that cascades multiple DCNNs that were trained on more than 200 CT scans. First, a V-net is used to create a rough liver, spleen, and stomach mask. After stomach and spleen pixels are removed using their respective masks and ascites is removed using a morphological algorithm, the scan is passed to a H-DenseUnet to yield the final segmentation. The segmentation accuracy of the pipleline was compared to the H-DenseUnet and the V-net using the SLIVER07 and 3DIRCADb datasets as benchmarks. The PADLLS Dice score for the SLIVER07 dataset was calculated to be 0.957 ± 0.033 and was significantly better than the H-DenseUnet's score of 0.927 ± 0.044 (p = 0.0219) and the V-net's score of 0.872 ± 0.121 (p = 0.0067). The PADLLS Dice score for the 3DIRCADb dataset was 0.965 ± 0.016 and was significantly better than the H-DenseUnet's score of 0.930 ± 0.041 (p = 0.0014) the V-net's score of 0.874 ± 0.060 (p < 0.001). In conclusion, our pipeline (PADLLS) outperforms existing liver segmentation models, serves as a valuable tool for image-based analysis, and is freely available for download and use.

Molecular MRI quantification of extracellular aldehyde pairs for early detection of liver fibrogenesis and response to treatment

Liver fibrosis plays a critical role in the evolution of most chronic liver diseases and is characterized by a buildup of extracellular matrix, which can progress to cirrhosis, hepatocellular carcinoma, liver failure, or death. Now, there are no noninvasive methods available to accurately assess disease activity (fibrogenesis) to sensitively detect early onset of fibrosis or to detect early response to treatment. Here, we hypothesized that extracellular allysine aldehyde (LysAld) pairs formed by collagen oxidation during active fibrosis could be a target for assessing fibrogenesis with a molecular probe. We showed that molecular magnetic resonance imaging (MRI) using an extracellular probe targeting these LysAld pairs acts as a noninvasive biomarker of fibrogenesis and demonstrated its high sensitivity and specificity in detecting fibrogenesis in toxin- and dietary-induced mouse models, a cholestasis rat model of liver fibrogenesis, and in human fibrotic liver tissues. Quantitative molecular MRI was highly correlated with fibrogenesis markers and enabled noninvasive detection of early onset fibrosis and response to antifibrotic treatment, showing high potential for clinical translation.

Skin Autofluorescence Measurement as Initial Assessment of Hepatic Parenchyma Quality in Patients Undergoing Liver Resection

Skin autofluorescence (SAF) can detect advanced glycation end products (AGEs) that accumulate in tissues over time. AGEs reflect patients’ general health, and their pathological accumulation has been associated with various diseases. This study aimed to determine whether its measurements can correlate with the liver parenchyma quality. This prospective study included 186 patients who underwent liver resections. Liver fibrosis and/or steatosis > 10% were found in almost 30% of the patients. ROC analysis for SAF revealed the optimal cutoff point of 2.4 AU as an independent predictor for macrovesicular steatosis ≥ 10% with an AUC of 0.629 (95% CI 0.538−0.721, p = 0.006), 59.9% sensitivity, 62.4% specificity, and positive (PPV) and negative (NPV) predictive values of 45.7% and 74.1%, respectively. The optimal cutoff point for liver fibrosis was 2.3 AU with an AUC of 0.613 (95% CI 0.519−0.708, p = 0.018), 67.3% sensitivity, 55.2% specificity, and PPV and NPV of 37.1% and 81.2%, respectively. In the multivariable logistic regression model, SAF ≥ 2.4 AU (OR 2.16; 95% CI 1.05−4.43; p = 0.036) and BMI (OR 1.21; 95% CI 1.10−1.33, p < 0.001) were independent predictors of macrovesicular steatosis ≥ 10%. SAF may enhance the available non-invasive methods of detecting hepatic steatosis and fibrosis in patients prior to liver resection.

Association between liver fibrosis and incident dementia in the UK Biobank study

BACKGROUND AND PURPOSE

There is growing recognition that chronic liver conditions influence brain health. The impact of liver fibrosis on dementia risk was unclear. We evaluated the association between liver fibrosis and incident dementia in a cohort study.

METHODS

We performed a cohort analysis using data from the UK Biobank study, which prospectively enrolled adults starting in 2007, and continues to follow them. People with a Fibrosis-4 (FIB-4) liver fibrosis score >2.67 were categorized as at high risk of advanced fibrosis. The primary outcome was incident dementia, ascertained using a validated approach. We excluded participants with prevalent dementia at baseline. We used Cox proportional hazards models to evaluate the association between liver fibrosis and dementia while adjusting for potential confounders.

RESULTS

Among 455,226 participants included in this analysis, the mean age was 56.5 years and 54% were women. Approximately 2.17% (95% confidence interval [CI] 2.13%-2.22%) had liver fibrosis. The rate of dementia per 1000 person-years was 1.76 (95% CI 1.50-2.07) in participants with liver fibrosis and 0.52 (95% CI 0.50-0.54) in those without. After adjusting for demographics, socioeconomic deprivation, educational attainment, metabolic syndrome, hypertension, diabetes, dyslipidemia, and tobacco and alcohol use, liver fibrosis was associated with an increased risk of dementia (hazard ratio 1.52, 95% CI 1.22-1.90). Results were robust to sensitivity analyses. Effect modification by sex, metabolic syndrome, and apolipoprotein E4 carrier status was not observed.

CONCLUSION

Liver fibrosis in middle age was associated with an increased risk of incident dementia, independent of shared risk factors. Liver fibrosis may be an underrecognized risk factor for dementia.

Quantitative Prediction of Steatosis in Patients with Non-Alcoholic Fatty Liver by Means of Hepatic MicroRNAs Present in Serum and Correlating with Hepatic Fat

Non-alcoholic fatty liver disease (NAFLD) is the most prevalent form of chronic liver disease worldwide, but a reliable non-invasive method to quantify liver steatosis in primary healthcare is not available. Circulating microRNAs have been proposed as biomarkers of severe/advanced NAFLD (steatohepatitis and fibrosis). However, the use of circulating miRNAs to quantitatively assess the % of liver fat in suspected NAFLD patients has not been investigated. We performed global miRNA sequencing in two sets of samples: human livers from organ donors (n = 20), and human sera from biopsy-proven NAFLD patients (n = 23), both with a wide range of steatosis quantified in their liver biopsies. Partial least squares (PLS) regression combined with recursive feature elimination (RFE) was used to select miRNAs associated with steatosis. Moreover, regression models with only 2 or 3 miRNAs, with high biological relevance, were built. Comprehensive microRNA sequencing of liver and serum samples resulted in two sets of abundantly expressed miRNAs (418 in liver and 351 in serum). Pearson correlation analyses indicated that 18% of miRNAs in liver and 14.5% in serum were significantly associated with the amount of liver fat. PLS-RFE models demonstrated that 50 was the number of miRNAs providing the lowest error in both liver and serum models predicting steatosis. Comparison of the two miRNA subsets showed 19 coincident miRNAs that were ranked according to biological significance (guide/passenger strand, relative abundance in liver and serum, number of predicted lipid metabolism target genes, correlation significance, etc.). Among them, miR-10a-5p, miR-98-5p, miR-19a-3p, miR-30e-5p, miR-32-5p and miR-145-5p showed the highest biological relevance. PLS regression models with serum levels of 2−3 of these miRNAs predicted the % of liver fat with errors <5%.

Missed diagnosis of cirrhosis in the inpatient setting

Cirrhosis accounts for a large number of deaths in the United States and worldwide, leading to an increasing burden on the healthcare system. Cirrhosis is, however, a progressive disease with different potential complications related to liver dysfunction and portal hypertension. Often, patients may present with complications of cirrhosis without having been diagnosed previously. It is pertinent that clinicians recognize these signs to place patients on an appropriate course of management to help delay or avoid further disease progression while avoiding deleterious outcomes and unnecessary utilization. We will discuss the epidemiology of liver disease, cirrhosis, and its complications (hepatic encephalopathy, ascites, and varices). In this study, we will discuss the rationale and impact of missing these diagnoses on the healthcare system and patient.

Development of a Robotic Shear Wave Elastography System for Noninvasive Staging of Liver Disease in Murine Models

Shear wave elastography (SWE) is an ultrasound-based stiffness quantification technology that is used for noninvasive liver fibrosis assessment. However, despite widescale clinical adoption, SWE is largely unused by preclinical researchers and drug developers for studies of liver disease progression in small animal models due to significant experimental, technical, and reproducibility challenges. Therefore, the aim of this work was to develop a tool designed specifically for assessing liver stiffness and echogenicity in small animals to better enable longitudinal preclinical studies. A high-frequency linear array transducer (12-24 MHz) was integrated into a robotic small animal ultrasound system (Vega; SonoVol, Inc., Durham, NC) to perform liver stiffness and echogenicity measurements in three dimensions. The instrument was validated with tissue-mimicking phantoms and a mouse model of nonalcoholic steatohepatitis. Female C57BL/6J mice (n = 40) were placed on choline-deficient, L-amino acid-defined, high-fat diet and imaged longitudinally for 15 weeks. A subset was sacrificed after each imaging timepoint (n = 5) for histological validation, and analyses of receiver operating characteristic (ROC) curves were performed. Results demonstrated that robotic measurements of echogenicity and stiffness were most strongly correlated with macrovesicular steatosis (R²  = 0.891) and fibrosis (R²  = 0.839), respectively. For diagnostic classification of fibrosis (Ishak score), areas under ROC (AUROCs) curves were 0.969 for ≥Ishak1, 0.984 for ≥Ishak2, 0.980 for ≥Ishak3, and 0.969 for ≥Ishak4. For classification of macrovesicular steatosis (S-score), AUROCs were 1.00 for ≥S2 and 0.997 for ≥S3. Average scanning and analysis time was <5 minutes/liver. Conclusion: Robotic SWE in small animals is feasible and sensitive to small changes in liver disease state, facilitating in vivo staging of rodent liver disease with minimal sonographic expertise.

The compound annual growth rate of the fibrosis-4 index in chronic hepatitis B patients

Chronic hepatitis B (CHB) patients with low disease activity are at risk of liver fibrosis. The age-adjusted fibrosis-4 index (FIB4-AA), developed in our previous publication, and was implemented to evaluate the tendency of liver fibrosis in these patients. We aimed to investigate the rate of liver fibrosis in CHB patients with low disease activity. Resuming our previous study, the FIB-4 changes of 244 antiviral treatment-naïve CHB patients, with a total of 1243.48 person-years, were reviewed. Among the cohort, patients were categorized as FIB4-AA positive or negative according to the results of their last FIB4-AA minus their initial FIB-4 during at least 18 months of observation time. The compound annual growth rate (CAGR) of FIB-4 was calculated for the FIB4-AA positive and negative groups. The assumed healthy controls had an FIB-4 CAGR calculated to be 2.34% for both men and women, while the FIB-4 CAGR of the whole study cohort was 2.84% ± 6.01%. FIB4-AA positive effectively identifies CHB patients with higher mean FIB-4 CAGR (7.11% ± 3.88% vs. -2.36% ± 3.52%, p < 0.0001). Overweight CHB patients had 10 times smaller mean FIB-4 CAGR than lean ones (0.38% ± 10.35% vs. 3.83% ± 8.88%, p = 0.009). An increase in FIB4-AA over at least 18 months in CHB patients with relatively low disease activity meant they were at greater risk of liver fibrosis, and these patients had a mean FIB-4 CAGR of 7.11%. The FIB-4 CAGR was compatible with the findings of previous studies on the collagen proportionate area in viral hepatitis patients.

Risk of hepatocellular carcinoma in patients with chronic hepatitis c infection and stage 3 fibrosis after sustained virological response

Evidence on the risk of hepatocellular carcinoma (HCC) in patients with stage 3 liver fibrosis (F3) and SVR is scarce and continues to generate uncertainty. Furthermore, the distinction between F3 and F4 disease is complex. Consequently, the latest international guidelines recommend using the same screening protocol for HCC after SVR in both F3 and F4 patients. However, the risk of HCC in these groups is possibly different and maintaining screening for HCC in this population indefinitely generates an excessive burden for the health system. This editorial aims to review the available evidence on this topic.

Biomarker modeling of Alzheimer's disease using PET-based Braak staging

Gold-standard diagnosis of Alzheimer's disease (AD) relies on histopathological staging systems. Using the topographical information from [18F]MK6240 tau positron-emission tomography (PET), we applied the Braak tau staging system to 324 living individuals. We used PET-based Braak stage to model the trajectories of amyloid-β, phosphorylated tau (pTau) in cerebrospinal fluid (pTau181, pTau217, pTau231 and pTau235) and plasma (pTau181 and pTau231), neurodegeneration and cognitive symptoms. We identified nonlinear AD biomarker trajectories corresponding to the spatial extent of tau-PET, with modest biomarker changes detectable by Braak stage II and significant changes occurring at stages III-IV, followed by plateaus. Early Braak stages were associated with isolated memory impairment, whereas Braak stages V-VI were incompatible with normal cognition. In 159 individuals with follow-up tau-PET, progression beyond stage III took place uniquely in the presence of amyloid-β positivity. Our findings support PET-based Braak staging as a framework to model the natural history of AD and monitor AD severity in living humans.

A Dual-Filtration System for Single-Cell Sequencing of Circulating Tumor Cells and Clusters in HCC

Hepatocellular carcinoma (HCC) is a leading cause of cancer death worldwide. Identification and sequencing of circulating tumor (CT) cells and clusters may allow for noninvasive molecular characterization of HCC, which is an unmet need, as many patients with HCC do not undergo biopsy. We evaluated CT cells and clusters, collected using a dual-filtration system in patients with HCC. We collected and filtered whole blood from patients with HCC and selected individual CT cells and clusters with a micropipette. Reverse transcription, polymerase chain reaction, and library preparation were performed using a SmartSeq2 protocol, followed by single-cell RNA sequencing (scRNAseq) on an Illumina MiSeq V3 platform. Of the 8 patients recruited, 6 had identifiable CT cells or clusters. Median age was 64 years old; 7 of 8 were male; and 7 of 8 had and Barcelona Clinic Liver Cancer stage C. We performed scRNAseq of 38 CT cells and 33 clusters from these patients. These CT cells and clusters formed two distinct groups. Group 1 had significantly higher expression than group 2 of markers associated with epithelial phenotypes (CDH1 [Cadherin 1], EPCAM [epithelial cell adhesion molecule], ASGR2 [asialoglycoprotein receptor 2], and KRT8 [Keratin 8]), epithelial-mesenchymal transition (VIM [Vimentin]), and stemness (PROM1 [CD133], POU5F1 [POU domain, class 5, transcription factor 1], NOTCH1, STAT3 [signal transducer and activator of transcription 3]) (P < 0.05 for all). Patients with identifiable group 1 cells or clusters had poorer prognosis than those without them (median overall survival 39 vs. 384 days; P = 0.048 by log-rank test). Conclusion: A simple dual-filtration system allows for isolation and sequencing of CT cells and clusters in HCC and may identify cells expressing candidate genes known to be involved in cancer biology. Presence of CT cells/clusters expressing candidate genes is associated with poorer prognosis in advanced-stage HCC.

Impact of non-invasive biomarkers on hepatology practice: Past, present and future

Over the last two decades, there have been tremendous advances in the non-invasive diagnosis and risk stratification of chronic liver diseases (CLDs). Non-invasive approaches are based on the quantification of biomarkers in serum samples or on the measurement of liver stiffness, using either ultrasound- or magnetic resonance-based elastography techniques. The fibrosis-4 index (non-patented) and enhanced liver fibrosis test (patented) are the most widely adopted serum markers, whereas vibration-controlled transient elastography is the most widely adopted elastography technique. In this review, we discuss the role of non-invasive tests in the current era, as well as their accuracy and how their use in clinical practice has changed the practice of hepatology, including identification of early cirrhosis in patients with risk factors for CLD, diagnosis of portal hypertension, establishing prognosis in compensated cirrhosis, guiding antiviral treatment, and screening for fibrosis and cirrhosis in primary care.

Shear wave elastography using sound touch elastography and supersonic shear imaging for liver measurements: a comparative study

BACKGROUND

Measurements of liver stiffness obtained with 2-dimensional shear wave elastography (2D-SWE) have been widely used to clinically assess liver fibrosis. However, differences between different 2D-SWE systems can lead to confusion when interpreting measurements. This study investigated the variability between a recently released sound touch elastography (STE) system and a supersonic shear imaging (SSI) system and assessed the degree of intersystem discrepancy using the different liver stiffness value (LSV) thresholds recommended by the Society of Radiologists in Ultrasound (SRU) for assessing liver fibrosis.

METHODS

A total of 4,152 patients who had undergone STE and SSI on the same day were enrolled in this retrospective study. First, intrasystem agreement for STE and SSI was assessed. Then, intraclass correlation coefficients (ICCs) and the Bland-Altman method were used to assess intersystem variability for all cases, classified according to the thresholds recommended by the SRU. The effects of age, gender, and body-mass index (BMI) were evaluated using multivariate linear regression analysis and attributive intervals were computed for STE and SSI at each of the different thresholds.

RESULTS

The ICCs for STE and SSI intrasystem agreement were 0.94 [95% confidence interval (CI): 0.937-0.943; P<0.001] and 0.984 (95% CI: 0.984-0.985; P<0.001), respectively. The 95% limit of agreement (LOA) for all cases ranged from -6.96 to 7.44 kPa. The 95% LOA increased as the threshold values rose, and intersystem variability was obvious, even at the smallest threshold (the 95% LOA at values ≤5 kPa was -0.85 to 2.08 kPa, while that at values >17 kPa was -20.81 to 14.71 kPa). The adjusted R2 for age, gender, and BMI was only 0.018 (all P value <0.05).

CONCLUSIONS

There was clear variability between STE and SSI, in contrast with some previous studies with small sample sizes, and consistent with others. Intersystem variability increased with the elevation of the LSV thresholds recommended by the SRU. Gender and BMI had little effect on intersystem variability. Future research could compare STE and SSI in different liver diseases, assessing the feasibility of the SRU-recommended thresholds in proven pathologies and evaluating the test-retest repeatability.

Trends in indirect liver function marker testing in Wales from 2000 to 2017 and their association with age and sex: an observational study

Objective

If non-invasive markers of liver fibrosis were recorded frequently enough in clinical practice, it might be feasible to use them for opportunistic community screening for liver disease. We aimed to determine their current pattern of usage in the national primary care population in Wales.

Design

Using the Secure Anonymised Information Linkage (SAIL) Databank at Swansea University (2000–2017), we quantified the frequency of common liver blood tests (aspartate aminotransferase (AST), alanine aminotransferase (ALT), platelet count and albumin) used in fibrosis marker algorithms. We examined measurement variation by age and sex.

Results

During the 18-year study period, there were 2 145 178 adult patients with at least one blood test available for analysis. Over the study period, the percentage of SAIL patients receiving an ALT test in each year increased from 2% to 33%, with platelet count and albumin measurement increasing by a similar factor. AST testing, although initially rising, had decreased to 1% by the end of the study. AST and ALT values varied by age and sex, particularly in males with the upper normal range of ALT values decreasing rapidly from 90 U/L at age 30 to 45 U/L by age 80.

Conclusion

The reduction in AST testing to only 1% of the adult population limits the use of many non-invasive liver marker algorithms. To enable widespread screening, alternative algorithms for liver fibrosis that do not depend on AST should be developed. Liver fibrosis markers should be modified to include age-specific and sex-specific normal ranges.

Vibration-controlled Transient Elastography for Assessment of Liver Fibrosis at a USA Academic Medical Center

Background and Aims

Vibration-controlled transient elastography (VCTE) is a noninvasive tool that uses liver stiffness measurement (LSM) to assess fibrosis. Since real-life data during everyday clinical practice in the USA are lacking, we describe the patterns of use and diagnostic performance of VCTE in patients at an academic medical center in New York City.

Methods

Patients who received VCTE scans were included if liver biopsy was performed within 1 year. Diagnostic performance of VCTE in differentiating dichotomized fibrosis stages was assessed via area under the receiver operating characteristics (AUROC). Fibrosis stage determined from VCTE LSM was compared to liver biopsy.

Results

Of 109 patients, 49 had nonalcoholic fatty liver disease, 16 chronic hepatitis C, 15 congestive hepatopathy, and 22 at least two etiologies. AUROC was 0.90 for differentiating cirrhosis (stage 4) with a positive predictive value (PPV) range of 0.28 to 0.45 and negative predictive value range of 0.96 to 0.98. For 31 (32%) patients, VCTE fibrosis stage was at least two stages higher than liver biopsy fibrosis stage. Thirteen of thirty-five patients considered to have cirrhosis by VCTE had stage 0 to 2 and 12 stage 3 fibrosis on liver biopsy.

Conclusions

VCTE has reasonable diagnostic accuracy and is reliable at ruling out cirrhosis. However, because of its low PPV, caution must be exercised when used to diagnose cirrhosis, as misdiagnosis can lead to unnecessary health care interventions. In routine practice, VTCE is also sometimes performed for disease etiologies for which it has not been robustly validated.

Heterogeneous Iron Oxide/Dysprosium Oxide Nanoparticles Target Liver for Precise Magnetic Resonance Imaging of Liver Fibrosis

Challenges remain in precisely diagnosing the progress of liver fibrosis in a noninvasive way. We here synthesized small (4 nm) heterogeneous iron oxide/dysprosium oxide nanoparticles (IO-DyO NPs) as a contrast agent (CA) for magnetic resonance imaging (MRI) to precisely diagnose liver fibrosis in vivo at both 7.0 and 9.4 T field strength. Our IO-DyO NPs can target the liver and show an increased T₂ relaxivity along with an increase of magnetic field strength. At a ultrahigh magnetic field, IO-DyO NPs can significantly improve spatial/temporal image resolution and signal-to-noise ratio of the liver and precisely distinguish the early and moderate liver fibrosis stages. Our IO-DyO NP-based MRI diagnosis can exactly match biopsy (a gold standard for liver fibrosis diagnosis in the clinic) but avoid the invasiveness of biopsy. Moreover, our IO-DyO NPs show satisfactory biosafety in vitro and in vivo. This work illustrates an advanced T₂ CA used in ultrahigh-field MRI (UHFMRI) for the precise diagnosis of liver fibrosis via a noninvasive means.

Reproducibility for Hepatocellular Carcinoma CT Radiomic Features: Influence of Delineation Variability Based on 3D-CT, 4D-CT and Multiple-Parameter MR Images

Purpose

Accurate lesion segmentation is a prerequisite for radiomic feature extraction. It helps to reduce the features variability so as to improve the reporting quality of radiomics study. In this research, we aimed to conduct a radiomic feature reproducibility test of inter-/intra-observer delineation variability in hepatocellular carcinoma using 3D-CT images, 4D-CT images and multiple-parameter MR images.

Materials and Methods

For this retrospective study, 19 HCC patients undergoing 3D-CT, 4D-CT and multiple-parameter MR scans were included in this study. The gross tumor volume (GTV) was independently delineated twice by two observers based on contrast-enhanced computed tomography (CECT), maximum intensity projection (MIP), LAVA-Flex, T2W FRFSE and DWI-EPI images. We also delineated the peritumoral region, which was defined as 0 to 5 mm radius surrounding the GTV. 107 radiomic features were automatically extracted from CECT images using 3D-Slicer software. Quartile coefficient of dispersion (QCD) and intraclass correlation coefficient (ICC) were applied to assess the variability of each radiomic feature. QCD<10% and ICC≥0.75 were considered small variations and excellent reliability. Finally, the principal component analysis (PCA) was used to test the feasibility of dimensionality reduction.

Results

For tumor tissues, the numbers of radiomic features with QCD<10% indicated no obvious inter-/intra-observer differences or discrepancies in 3D-CT, 4D-CT and multiple-parameter MR delineation. However, the number of radiomic features (mean 89) with ICC≥0.75 was the highest in the multiple-parameter MR group, followed by the 3DCT group (mean 77) and the MIP group (mean 73). The peritumor tissues also showed similar results. A total of 15 and 7 radiomic features presented excellent reproducibility and small variation in tumor and peritumoral tissues, respectively. Two robust features showed excellent reproducibility and small variation in tumor and peritumoral tissues. In addition, the values of the two features both represented statistically significant differences among tumor and peritumoral tissues (P<0.05). The PCA results indicated that the first seven principal components could preserve at least 90% of the variance of the original set of features.

Conclusion

Delineation on multiple-parameter MR images could help to improve the reproducibility of the HCC CT radiomic features and weaken the inter-/intra-observer influence.

Alpha-1 antitrypsin deficiency: A re-surfacing adult liver disorder

Alpha-1 antitrypsin deficiency (AATD) arises from mutations in the SERPINA1 gene encoding alpha-1 antitrypsin (AAT) that lead to AAT retention in the endoplasmic reticulum of hepatocytes, causing proteotoxic liver injury and loss-of-function lung disease. The homozygous Pi∗Z mutation (Pi∗ZZ genotype) is responsible for the majority of severe AATD cases and can precipitate both paediatric and adult liver diseases, while the heterozygous Pi∗Z mutation (Pi∗MZ genotype) is an established genetic modifier of liver disease. We review genotype-related hepatic phenotypes/disease predispositions. We also describe the mechanisms and factors promoting the development of liver disease, as well as approaches to evaluate the extent of liver fibrosis. Finally, we discuss emerging diagnostic and therapeutic approaches for the clinical management of this often neglected disorder.

Increasing on-treatment hepatocellular carcinoma risk with decreasing baseline viral load in HBeAg-positive chronic hepatitis B

BACKGROUND

It is unclear whether the level of serum hepatitis B virus (HBV) DNA at baseline affects the on-treatment risk of hepatocellular carcinoma (HCC) in hepatitis B e antigen–positive (HBeAg-positive), noncirrhotic patients with chronic hepatitis B (CHB).

METHODS

We conducted a multicenter cohort study including 2073 entecavir- or tenofovir-treated, HBeAg-positive, noncirrhotic adult CHB patients with baseline HBV DNA levels of 5.00 log₁₀ IU/mL or higher at 3 centers in South Korea between January 2007 and December 2016. We evaluated the on-treatment incidence rate of HCC according to baseline HBV DNA levels.

RESULTS

During a median 5.7 years of continuous antiviral treatment, 47 patients developed HCC (0.39 per 100 person-years). By Kaplan-Meier analysis, the risk of HCC was lowest in patients with baseline HBV DNA levels of 8.00 log₁₀ IU/mL or higher, increased incrementally with decreasing viral load, and was highest in those with HBV DNA levels of 5.00–5.99 log₁₀ IU/mL (P < 0.001). By multivariable analysis, the baseline HBV DNA level was an independent factor that was inversely associated with HCC risk. Compared with HBV DNA levels of 8.00 log₁₀ IU/mL or higher, the adjusted HRs for HCC risk with HBV DNA levels of 7.00–7.99 log₁₀ IU/mL, 6.00–6.99 log₁₀ IU/mL, or 5.00–5.99 log₁₀ IU/mL were 2.48 (P = 0.03), 3.69 (P = 0.002), and 6.10 (P < 0.001), respectively.

CONCLUSION

On-treatment HCC risk increased incrementally with decreasing baseline HBV DNA levels in the range of 5.00 log₁₀ IU/mL or higher in HBeAg-positive, noncirrhotic adult patients with CHB. Early initiation of antiviral treatment when the viral load is high (≥8.00 log₁₀ IU/mL) may maintain the lowest risk of HCC for those patients.

FUNDING

Patient-Centered Clinical Research Coordinating Center (PACEN) (grant no. HC20C0062) of the National Evidence-based Healthcare Collaborating Agency; National R&D Program for Cancer Control through the National Cancer Center (grant no. HA21C0110), Ministry of Health and Welfare, South Korea.

Laparoscopic liver resection for hepatocellular carcinoma complicated with significant portal hypertension: A propensity score-matched survival analysis

BACKGROUND

Significant portal hypertension (SPH) is a relative contraindication for patients with resectable hepatocellular carcinoma (HCC). However, increasing evidence indicates that liver resection is feasible for HCC patients with SPH.

METHODS

HCC patients with cirrhosis who underwent laparoscopic liver resection (LLR) in two centers from January 2013 to April 2018 were included. Surgical and survival outcomes were analyzed to explore potential prognostic factors. Propensity score matching (PSM) analysis was performed to minimize bias.

RESULTS

A total of 165 patients were divided into two groups based on the presence (SPH, n = 76) or absence (non-SPH, n = 89) of SPH. Patients in the SPH group had longer operative time, more blood loss, and more advanced TNM stage than patients in the non-SPH group (P < 0.05). However, there were no significant differences in the postoperative 90-day mortality rate (n = 0), overall postoperative complications (47.4% vs. 41.6%, P = 0.455), Clavien-Dindo classification (P = 0.347), conversion to open surgery (9.2% vs. 6.7%, P = 0.557), or length of hospitalization (16 vs. 15 days, P = 0.203) between SPH and non-SPH groups before PSM. Similar results were obtained after PSM. The 1-, 3-, and 5-year overall survival (OS) and recurrence-free survival rates in the SPH group were not significantly different from those in the non-SPH group both before and after PSM (log-rank P > 0.05).After PSM, alpha-fetoprotein (AFP) ≥ 400 μg/L [hazard ratio (HR) = 4.71, 95% confidence interval (CI): 2.69-8.25], ascites (HR = 2.18, 95% CI: 1.30-3.66), American Society of Anesthesiologists (ASA) classification (III vs. II) (HR = 2.13, 95% CI: 1.11-4.07) and tumor diameter > 5 cm (HR = 3.91, 95% CI: 2.02-7.56) independently predicted worse OS.

CONCLUSIONS

LLR for patients with HCC complicated with SPH appears feasible at the price of increasing operative time and blood loss. AFP, ascites, ASA classification and tumor diameter may predict the prognosis of HCC complicated with SPH after LLR.

Evaluation of liver fibrosis in chronic hepatitis B patients with 2D shear wave elastography with propagation map guidance: a single-centre study

Background

The aims of this study were to evaluate liver fibrosis with two-dimensional (2D) shear wave elastography (SWE) in patients with chronic hepatitis B (CHB), to compare 2D-SWE with histopathology and to determine the change in liver stiffness values after antiviral therapy.

Material and methods

A total of 253 patients with CHB were included in this prospective study. 2D-SWE with propagation map guidance to measure liver stiffness, fibrosis-4 index (FIB-4) and aspartate aminotransferase to platelet ratio index (APRI) scoring and additional liver biopsy were performed in patients with CHB. Liver stiffness was measured again at 24 and 48 weeks in all patients. The Spearman rank correlation test was used to analyse the correlation between variables, and receiver operating curve analysis was used to evaluate the diagnostic performance in terms of fibrosis.

Results

Liver stiffness measurements made with 2D-SWE demonstrated a significant positive correlation with the fibrosis stage and FIB-4 score (r_s = 0.774 and 0.337, respectively, p < 0.001 for both). The area under the curve value for kPa for the prediction of significant fibrosis was 0.956 (95% CI_s) (0.920–0.991), and the optimal cut-off value was 8.2 kPa (sensitivity: 92.7% and specificity: 78.9%); these values were 0.978 (95% CI_s, 0.945–1.000) and 10.1 kPa (sensitivity: 92.9% and specificity: 96.4%) for the prediction of severe fibrosis. After antiviral treatment, a decrease in liver stiffness values measured by 2D-SWE was detected (mean kPa values at 0 and 48 weeks; 9.24 and 7.36, respectively, p < 0.001).

Conclusion

In conclusion, the measurement of liver stiffness with 2D-SWE has high diagnostic performance in the determination of hepatic fibrosis and can be used to evaluate the response to treatment in patients receiving antiviral therapy.

Association of chronic liver disease with cognition and brain volumes in two randomized controlled trial populations

BACKGROUND AND PURPOSE

We examined the association of chronic liver disease with cognition and brain imaging markers of cognitive impairment using data from two large randomized controlled trials that included participants based on diabetes and hypertension, two common systemic risk factors for cognitive impairment and dementia.

METHODS

We performed post hoc analyses using data from the Action to Control Cardiovascular Risk in Diabetes (ACCORD) and Systolic Blood Pressure Intervention Trial (SPRINT) studies, which included participants with diabetes and hypertension, respectively. Data were from the NHLBI Biologic Specimen and Data Repository Information Coordinating Center. In ACCORD, our measure of chronic liver disease was the Dallas Steatosis Index (DSI). In SPRINT, we used self-reported chronic liver disease. We used linear regression to evaluate the association between the measure of chronic liver disease and both baseline and longitudinal cognitive test performance and brain magnetic resonance imaging volume measurements.

RESULTS

Among 2969 diabetic participants in ACCORD, the mean age of participants was 62 years, 47% were women. The median DSI was 1.0 (IQR, 0.2-1.8); a DSI of 1.0 corresponds to approximately a > 70% probability of having NAFLD. Among 2890 hypertensive participants in SPRINT, the mean age was 68 years, and 37% were women, and 60 (2.1%) had chronic liver disease. There were no consistent associations between liver disease and cognitive performance or brain volumes at baseline or longitudinally after adjustment.

CONCLUSION

Markers of chronic liver disease were not associated with cognitive impairment or related brain imaging markers among individuals with diabetes and hypertension.

Comparison of Non-Invasive Clinical Algorithms for Liver Fibrosis in Patients With Chronic Hepatitis B to Reduce the Need for Liver Biopsy: Application of Enhanced Liver Fibrosis and Mac-2 Binding Protein Glycosylation Isomer

BACKGROUND

Non-invasive clinical algorithms for the detection of liver fibrosis (LF) can reduce the need for liver biopsy (LB). We explored the implementation of two serum biomarkers, enhanced liver fibrosis (ELF) and Mac-2 binding protein glycosylation isomer (M2BPGi), in clinical algorithms for LF in chronic hepatitis B (CHB) patients.

METHODS

Two clinical algorithms were applied to 152 CHB patients: (1) transient elastography (TE) followed by biomarkers (TE/ELF and TE/M2GPGi); (2) biomarker test followed by TE (ELF/TE and M2BPGi/TE). Using the cut-off value or index for the detection of advanced LF (TE≥F3; 9.8 in ELF and 3.0 in M2BPGi), LB was expected to be performed in cases with discordant TE and biomarker results.

RESULTS

In both algorithms, the expected number of LBs was lower when using M2BPGi than when using ELF (TE/ELF or ELF/TE, 13.2% [N=20]; TE/M2BPGi or M2BPGi/TE, 9.9% [N=15]), although there was no statistical difference (P=0.398). In the TE low-risk group (TE≤F2), the discordance rate was significantly lower in the TE/M2BPGi approach than in the TE/ELF approach (1.5% [2/136] vs. 11.0% [15/136], P=0.002). In the biomarker low-risk group, there was no significant difference between the ELF/TE and M2BPGi/TE approaches (3.9% [5/126] vs. 8.8% [13/147], P=0.118).

CONCLUSIONS

Both ELF and M2BPGi can be implemented in non-invasive clinical algorithms for assessing LF in CHB patients. Given the lowest possibility of losing advanced LF cases in the low-risk group when using the TE/M2BPGi approach, this combination seems useful in clinical practice.

Diffusion MRI signal cumulants and hepatocyte microstructure at fixed diffusion time: Insights from simulations, 9.4T imaging, and histology

Purpose

Relationships between diffusion‐weighted MRI signals and hepatocyte microstructure were investigated to inform liver diffusion MRI modeling, focusing on the following question: Can cell size and diffusivity be estimated at fixed diffusion time, realistic SNR, and negligible contribution from extracellular/extravascular water and exchange?

Methods

Monte Carlo simulations were performed within synthetic hepatocytes for varying cell size/diffusivity L/D0, and clinical protocols (single diffusion encoding; maximum b‐value: {1000, 1500, 2000} s/mm²; 5 unique gradient duration/separation pairs; SNR = {∞, 100, 80, 40, 20}), accounting for heterogeneity in (D0,L) and perfusion contamination. Diffusion (D) and kurtosis (K) coefficients were calculated, and relationships between (D0,L) and (D,K) were visualized. Functions mapping (D,K) to (D0,L) were computed to predict unseen (D0,L) values, tested for their ability to classify discrete cell‐size contrasts, and deployed on 9.4T ex vivo MRI‐histology data of fixed mouse livers

Results

Relationships between (D,K) and (D0,L) are complex and depend on the diffusion encoding. Functions mapping D,K to (D0,L) captures salient characteristics of D0(D,K) and L(D,K) dependencies. Mappings are not always accurate, but they enable just under 70% accuracy in a three‐class cell‐size classification task (for SNR = 20, bmax = 1500 s/mm², δ = 20 ms, and Δ = 75 ms). MRI detects cell‐size contrasts in the mouse livers that are confirmed by histology, but overestimates the largest cell sizes.

Conclusion

Salient information about liver cell size and diffusivity may be retrieved from minimal diffusion encodings at fixed diffusion time, in experimental conditions and pathological scenarios for which extracellular, extravascular water and exchange are negligible.

Advances in fibrosis biomarkers in nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) affects a quarter of the adult world population and the degree of liver fibrosis represents the best predictor of the development of liver-related outcomes. Easily applicable and well performing non-invasive fibrosis tests can overcome the limitations of liver biopsy and are of paramount importance to identify at-risk subjects in clinical practice. While tests with optimal performance and ease of use do not exist at this stage, available markers can be divided in three broad groups: simple serum tests, complex serum tests and elastographic methods. Simple scores (such as Fibrosis-4 and NAFLD Fibrosis Score) are based on readily available biochemical data and clinical features, while complex/proprietary tests (such as Fibrotest, Enhanced Liver Fibrosis and Hepascore) directly measure markers of fibrogenesis and fibrolysis, but have higher costs. Elastography techniques estimate the degree of fibrosis from liver stiffness and are based on either ultrasound or magnetic resonance (MR) imaging. MR elastography has better performance compared with sonographic techniques and is not affected by obesity and inflammation, but is highly costly and less available. In general, non-invasive tests are able to exclude the presence of fibrosis, but their positive predictive value is low to moderate and they lead to a high number of indeterminate results. In this context, a combination of different tests might increase accuracy while reducing gray-zone results. Their ability to predict future events and response to treatment is suboptimal and needs to be studied further. Finally, recent studies have tried different approaches, spanning from "omics" to the microbiome and micro-RNAs, with some promising results.

The Concept of Indeterminable NASH Inducted by Preoperative Diet and Metabolic Surgery: Analyses of Histopathological and Clinical Features

Practitioners routinely perform intraoperative liver biopsies during laparoscopic sleeve gastrectomy (LSG) to evaluate nonalcoholic fatty liver disease (NAFLD). In some patients, hepatocyte ballooning, inflammation, and fibrosis without steatosis are observed, even in the absence of other etiologies. We call this finding indeterminable nonalcoholic steatohepatitis (Ind-NASH). In this study, we clarified the prevalence, as well as histopathological and clinical features, of Ind-NASH through intraoperative liver biopsy in Japanese patients presenting with severe obesity. We enrolled 63 patients who had undergone LSG and intraoperative liver biopsy. In patients diagnosed with histopathological NASH, we performed protocol liver biopsies at 6 and 12 months after LSG. We statistically analyzed these histopathological findings and clinical parameters and found the prevalence rate of Ind-NASH discovered through intraoperative biopsy to be 15.9%. Protocol liver biopsy also revealed that Ind-NASH was an intermediate condition between NASH and normal liver. The clinical features of patients with Ind-NASH are a higher body weight compared to NASH (134.9 kg vs. 114.7 kg; p = 0.0245), stronger insulin resistance compared to nonalcoholic fatty liver (homeostasis model assessment–insulin resistance: 7.1 vs. 4.9; p = 0.0188), and mild liver dysfunction compared to NASH. Patients with Ind-NASH observed positive weight-loss effects from a preoperative diet compared to the postoperative course (percentage total weight loss: 32.0% vs. 26.7%; p < 0.0001). Patients with Ind-NASH may also be good candidates for metabolic surgery owing to their good treatment response; therefore, efforts should be made by specialists in the near future to deeply discuss and define Ind-NASH.

Fibroblast Growth Factor 19 and Fibroblast Growth Factor 21 Regulation in Obese Diabetics, and Non-Alcoholic Fatty Liver Disease after Gastric Bypass

Background: Gastric bypass (GB) is an effective treatment for those who are morbidly obese with coexisting type 2 diabetes mellitus (T2DM) or non-alcoholic fatty liver disease (NAFLD). Fibroblast growth factors (FGFs) are involved in the regulation of energy metabolism. Methods: We investigated the roles of FGF 19, FGF 21, and total bile acid among those with morbidly obese and T2DM undergoing GB. A total of 35 patients were enrolled. Plasma FGF 19, FGF 21, and total bile acid levels were measured before surgery (M0), 3 months (M3), and 12 months (M12) after surgery, while the hepatic steatosis index (HSI) was calculated before and after surgery. Results: Obese patients with T2DM after GB presented with increased serum FGF 19 levels (p = 0.024) and decreased total bile acid (p = 0.01) and FGF 21 levels (p = 0.005). DM complete remitters had a higher FGF 19 level at M3 (p = 0.004) compared with DM non-complete remitters. Fatty liver improvers tended to have lower FGF 21 (p = 0.05) compared with non-improvers at M12. Conclusion: Changes in FGF 19 and FGF 21 play differential roles in DM remission and NAFLD improvement for patients after GB. Early increases in serum FGF 19 levels may predict complete remission of T2DM, while a decline in serum FGF 21 levels may reflect the improvement of NAFLD after GB.

Association of obstructive sleep apnea with non-alcoholic fatty liver disease in patients with obesity: an observational study

PURPOSE

Obstructive Sleep Apnea (OSA) is associated with the presence and severity of Non-Alcoholic Fatty Liver Disease (NAFLD). We aimed to investigate the relationship between the severity of OSA and NAFLD and to recognize a polysomnographic parameter correlated with progression of fibrosis, determined by a non-invasive score of liver fibrosis, FIBrosis-4 index (FIB-4), in patients affected by severe obesity and OSA.

METHODS

We enrolled 334 patients (Body Mass Index, BMI 44.78 ± 8.99 kg/m²), divided into classes according to severity of OSA evaluated with Apnea Hypopnea Index (AHI): OSAS 0 or absent (17%), mild OSA (26%), moderate OSA (20%), severe OSAS (37%). We studied anthropometric, polysomnographic, biochemical data and FIB-4. A multiple regression model was computed to identify a polysomnographic independent predictor of FIB-4 among those parameters previously simple correlated with FIB-4.

RESULTS

The severity of OSA was associated with a decrease in High-Density Lipoprotein-cholesterol (HDL) and an increase in BMI, triglycerides, Homeostasis model assessment insulin-resistance index (HOMA), transaminases and FIB-4. FIB-4 correlated with sex, age, BMI, AHI, mean percentage oxyhaemoglobin (meanSaO2%), number of desaturations, platelets, transaminases, HDL, triglycerides and HOMA. The only variables independently related to FIB-4 were sex, BMI, triglycerides and meanSpO2 (r = 0.47, AdjRsqr = 0.197).

CONCLUSION

MeanSpO2% represented an independent determinant for the worsening of FIB-4 in patients with severe obesity and OSA. Hence, it could hypothesize a clinical role of meanSaO2% in recognizing patients with obesity and OSA and higher risk of developing advanced fibrosis and, thus, to undergo further investigation.

LEVEL III

Evidence obtained from well-designed cohort analytic studies.

Diagnostic efficacy of FibroScan for liver inflammation in patients with chronic hepatitis B: a single-center study with 1185 liver biopsies as controls

Background

Noninvasive diagnostic technologies that can dynamically monitor changes in liver inflammation are highly important for the management of chronic hepatitis B (CHB) patients and thus warrant further exploration. This study assessed the diagnostic efficacy of FibroScan for liver inflammation in CHB patients.

Methods

A total of 1185 patients were selected, and ultrasound-guided liver biopsy was performed within 1 month after the FibroScan test. The liver stiffness measurement (LSM), the reliability criteria (IQR/M) of LSM, the quality of liver biopsy (complete portal area, PA), and the liver inflammation grades were the main observation items of this study. With liver biopsy as the control, the diagnostic efficacy of FibroScan for liver inflammation in CHB patients was evaluated by receiver operating characteristic (ROC) curve analysis.

Results

The grade of liver inflammation was positively correlated with the stage of fibrosis (rho = 0.829, P < 0.001). Different grades of inflammation will have significant rise in LSM values within the same fibrosis stage, and LSM values were positively correlated with liver inflammation grade and fibrosis stage, and the rho is 0.579 and 0.593 respectively (P < 0.001). Significant differences in the LSM of FibroScan were observed among different grades of liver inflammation (P < 0.0001). Liver biopsy (PA > 10) served as the control, and the cutoff point and the area under ROC curves (AUCs) of the LSMs for different inflammation grades were as follows: G2, 8.6 kPa, 0.775; G3 9.8 kPa, 0.818; and G4, 11.0 kPa; 0.832. With LSM cutoff values of 8.6 kPa, 9.8 kPa and 11.0 kPa, FibroScan showed certain diagnostic value for CHB patients with G2, G3 and G4 liver inflammation, especially those with G4 inflammation.

Conclusions

The grade of liver inflammation was positively correlated with the stage of fibrosis, different grades of inflammation will have significant rise in LSM values within the same fibrosis stage. In addition to liver fibrosis, FibroScan could evaluate liver inflammation in CHB patients in a noninvasive manner.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-022-02108-0.

Automatic Classification of Fatty Liver Disease Based on Supervised Learning and Genetic Algorithm

Fatty liver disease is considered a critical illness that should be diagnosed and detected at an early stage. In advanced stages, liver cancer or cirrhosis arise, and to identify this disease, radiologists commonly use ultrasound images. However, because of their low quality, radiologists found it challenging to recognize this disease using ultrasonic images. To avoid this problem, a Computer-Aided Diagnosis technique is developed in the current study, using Machine Learning Algorithms and a voting-based classifier to categorize liver tissues as being fatty or normal, based on extracting ultrasound image features and a voting-based classifier. Four main contributions are provided by our developed method: firstly, the classification of liver images is achieved as normal or fatty without a segmentation phase. Secondly, compared to our proposed work, the dataset in previous works was insufficient. A combination of 26 features is the third contribution. Based on the proposed methods, the extracted features are Gray-Level Co-Occurrence Matrix (GLCM) and First-Order Statistics (FOS). The fourth contribution is the voting classifier used to determine the liver tissue type. Several trials have been performed by examining the voting-based classifier and J48 algorithm on a dataset. The obtained TP, TN, FP, and FN were 94.28%, 97.14%, 5.71%, and 2.85%, respectively. The achieved precision, sensitivity, specificity, and F1-score were 94.28%, 97.05%, 94.44%, and 95.64%, respectively. The achieved classification accuracy using a voting-based classifier was 95.71% and in the case of using the J48 algorithm was 93.12%. The proposed work achieved a high performance compared with the research works.

Identification and Validation of Novel Serum Autoantibodies Biomarkers for Staging Liver Fibrosis in Patients With Chronic Hepatitis B

Aim: Liver fibrosis monitoring is essential in patients with chronic hepatitis B (CHB). However, less robust, noninvasive diagnostic methods for staging liver fibrosis, other than liver biopsy, are available. Our previous study demonstrated a panel of cellular proteins recognized by autoantibodies that may have potential value in discrimination of CHB and liver cirrhosis. We aim to assess the diagnostic value of these serum autoantibodies for staging liver fibrosis. Methods: Candidate autoantigens were screened and assessed by microarray analysis in 96 healthy controls and 227 CHB patients with pre-treatment biopsy-proven METAVIR fibrosis score, comprising 69, 115, and 43 cases with S0-1, S2-3, and S4 stages, respectively. Autoantibodies with potential diagnostic value for staging liver fibrosis were verified by enzyme-linked immunosorbent assays (ELISA). Receiver operating characteristic curve was conducted to evaluate autoantibody performance. Results: Microarray analysis identified autoantigens CENPF, ACY1, HSPA6, and ENO1 with potential diagnostic value for liver fibrosis staging, among which CENPF and ACY1 were validated using ELISA. CENPF and ACY1 autoantibodies had area under the curve values of 0.746 and 0.685, 58.14 and 74.42% sensitivity, and 88.41 and 60.87% specificity, respectively, for discriminating liver fibrosis stages S4 and S0-1. The prevalence of CENPF and ACY1 autoantibodies was not correlated with age, sex or level of inflammation. Conclusions: Autoimmune responses may be elicited during progression of liver fibrosis, and serum autoantibodies may be a valuable biomarker for staging liver fibrosis deserving of further study.

Liver Fat Assessment in Multiview Sonography Using Transfer Learning With Convolutional Neural Networks

OBJECTIVES

To develop and evaluate deep learning models devised for liver fat assessment based on ultrasound (US) images acquired from four different liver views: transverse plane (hepatic veins at the confluence with the inferior vena cava, right portal vein, right posterior portal vein) and sagittal plane (liver/kidney).

METHODS

US images (four separate views) were acquired from 135 participants with known or suspected nonalcoholic fatty liver disease. Proton density fat fraction (PDFF) values derived from chemical shift-encoded magnetic resonance imaging served as ground truth. Transfer learning with a deep convolutional neural network (CNN) was applied to develop models for diagnosis of fatty liver (PDFF ≥ 5%), diagnosis of advanced steatosis (PDFF ≥ 10%), and PDFF quantification for each liver view separately. In addition, an ensemble model based on all four liver view models was investigated. Diagnostic performance was assessed using the area under the receiver operating characteristics curve (AUC), and quantification was assessed using the Spearman correlation coefficient (SCC).

RESULTS

The most accurate single view was the right posterior portal vein, with an SCC of 0.78 for quantifying PDFF and AUC values of 0.90 (PDFF ≥ 5%) and 0.79 (PDFF ≥ 10%). The ensemble of models achieved an SCC of 0.81 and AUCs of 0.91 (PDFF ≥ 5%) and 0.86 (PDFF ≥ 10%).

CONCLUSION

Deep learning-based analysis of US images from different liver views can help assess liver fat.

Value of Liver Function Tests in Cirrhosis

The liver comprises both parenchymal and non-parenchymal cells with varying functions. Cirrhosis is often complicated by the development of portal hypertension and its associated complications. Hence, assessment of liver in cirrhosis should include assessment of its structural, function of both hepatic and non-hepatic tissue and haemodynamic assessment of portal hypertension. There is no single test that can evaluate all functions of liver and assess prevalence and severity of portal hypertension. Commonly available tests like serum bilirubin, liver enzymes (alanine [ALT] and aspartate aminotransferase [AST], serum alkaline phosphatase [ALP], gamma glutamyl transpeptidase [GGT]), serum albumin and prothrombin time for assessment of liver functions partly assess liver functions. quantitative liver functions like indocyanine clearance tests [ICG-K], methacetin breath test [MBT] were developed to assess dynamic status of liver but has its own limitation and availability. Imaging based assessment of liver by transient elastography, MRI based 99 mTc-coupled asialoglycoprotein mebrofenin scan help the clinician to assess liver function, functional volume of liver left after surgery and portal hypertension [PH]. Hepatic venous pressure gradient still remains the gold standard for the assessment of portal hypertension but is invasive and not available in all centres. Combinations of blood parameters in form of various indices like fibrosis score of 4 [FIB-4], Lok index, scores like model for end stage liver disease (MELD) and Child-Turcotte Pugh score are commonly used for assessing liver function in clinical practice.

Comparing and combining MRE, T1ρ, SWI, IVIM, and DCE-MRI for the staging of liver fibrosis in rabbits: Assessment of a predictive model based on multiparametric MRI

PURPOSE

To establish and validate an optimal predictive model based on multiparametric MRI for staging liver fibrosis (LF) in rabbits with magnetic resonance elastography (MRE), spin-lattice relaxation time in the rotating frame (T1ρ imaging), SWI, intravoxel incoherent motion (IVIM), and DCE-MRI.

METHODS

The LF group included 120 rabbits induced by subcutaneous injections of carbon tetrachloride (CCl₄ ); 30 normal rabbits served as the control group. Multiparametric MRI was performed, including MRE, T1ρ, SWI, IVIM, and DCE-MRI. The quantitative parameters were analyzed in two groups, with histopathological results serving as the reference standard. The diagnostic performance of multiparametric MRI and the predictive model established by multivariable logistic regression analysis were evaluated by receiver operating characteristic (ROC) curve analysis.

RESULTS

In total, 32, 67, and 51 rabbits were histologically diagnosed as no fibrosis (stage F0), early-stage LF (F1-F2), and advanced-stage LF (F3-F4), respectively. The LF stages presented a strong correlation with liver stiffness (LS) on MRE (r = 0.90), signal-intensity ratio (SIR) on SWI (r = -0.84), and K^trans on DCE-MRI (r = 0.71; p < 0.05 for all). The LS and SIR parameters had higher AUC values for distinguishing early-stage LF from both no fibrosis (0.94 and 0.93, respectively) and advanced-stage LF (0.95 and 0.87, respectively). The predictive model showed a slightly higher AUC value of 0.97 (0.90-0.99) than LS and SIR in distinguishing early-stage LF from no fibrosis (p > 0.05), a significantly higher AUC value of 0.98 (0.93-0.99) than the SIR in distinguishing early-stage from advanced-stage LF (p < 0.05).

CONCLUSION

SWI, DCE-MRI, and MRE in particular showed improved performance for LF diagnosis and stage. The predictive model based on multiparametric MRI was found to further enhance diagnostic accuracy and could serve as an excellent imaging tool for staging LF.

Clinical impact of the Model for End Liver Disease (MELD) score on the presence of microvascular invasion and on the postoperative outcome in patients undergoing liver transplantation

OBJECTIVE

to correlate clinical and epidemiological data with the pathological analysis of liver explants from patients undergoing liver transplantation for hetapocarcinoma in the UNICAMP HC and to verify whether the MELD and MELD-Na scores are reliable factors to predict a worse post-transplant prognosis.

METHODS

we studied liver transplants carried out between May 2010 and November 2017. After excluding 38 patients, we included 87, analyzing clinical and laboratory data for correlation with the outcome Microvascular Invasion (MVI). Subsequently, we computed the MELD and MELD-Na scores and performed a descriptive analysis of clinical and laboratory data and, finally, calculated ROC curves to assess the association between these laboratory parameters and mortality in these patients.

RESULTS

most patients were male (78.30%), with an average age of 58.53 years. Most liver diseases were caused by HCV (53.26%). We found no predictors for MVI among the laboratory parameters. The ROC curves for death identified the MELD score as the cutoff point with the highest combined sensitivity (90.91%) and specificity (37.50%), with a value of 10 points, whereas in the MELD-Na the cutoff point was 7 points, with a sensitivity of 90.91% and a specificity of 33.33%, both scores being significant.

CONCLUSIONS

there were no reliable predictors of MVI between clinical, laboratory, and epidemiological variables. The MELD-Na score is more sensitive than the MELD one for predicting mortality in patients undergoing liver transplantation.

Comparative diagnostic performance of ultrasound shear wave elastography and magnetic resonance elastography for classifying fibrosis stage in adults with biopsy-proven nonalcoholic fatty liver disease

Objectives

To compare the diagnostic accuracy of US shear wave elastography (SWE) and magnetic resonance elastography (MRE) for classifying fibrosis stage in patients with nonalcoholic fatty liver disease (NAFLD).

Methods

Patients from a prospective single-center cohort with clinical liver biopsy for known or suspected NAFLD underwent contemporaneous SWE and MRE. AUCs for classifying biopsy-determined liver fibrosis stages ≥ 1, ≥ 2, ≥ 3, and = 4, and their respective performance parameters at cutoffs providing ≥ 90% sensitivity or specificity were compared between SWE and MRE.

Results

In total, 100 patients (mean age, 51.8 ± 12.9 years; 46% males; mean BMI 31.6 ± 4.7 kg/m²) with fibrosis stage distribution (stage 0/1/2/3/4) of 43, 36, 5, 10, and 6%, respectively, were included. AUCs (and 95% CIs) for SWE and MRE were 0.65 (0.54–0.76) and 0.81 (0.72–0.89), 0.81 (0.71–0.91) and 0.94 (0.89–1.00), 0.85 (0.74–0.96) and 0.95 (0.89–1.00), and 0.91 (0.79–1.00) and 0.92 (0.83–1.00), for detecting fibrosis stage ≥ 1, ≥ 2, ≥ 3, and = 4, respectively. The differences were significant for detecting fibrosis stage ≥ 1 and ≥ 2 (p < 0.01) but not otherwise. At ≥ 90% sensitivity cutoff, MRE yielded higher specificity than SWE at diagnosing fibrosis stage ≥ 1, ≥ 2, and ≥ 3. At ≥ 90% specificity cutoff, MRE yielded higher sensitivity than SWE at diagnosing fibrosis stage ≥ 1 and ≥ 2.

Conclusions

In adults with NAFLD, MRE was more accurate than SWE in diagnosing stage ≥ 1 and ≥ 2 fibrosis, but not stage ≥ 3 or 4 fibrosis.

Key Points

• For detecting any fibrosis or mild fibrosis, MR elastography was significantly more accurate than shear wave elastography.

• For detecting advanced fibrosis and cirrhosis, MRE and SWE did not differ significantly in accuracy.

• For excluding advanced fibrosis and potentially ruling out the need for biopsy, SWE and MRE did not differ significantly in negative predictive value.

• Neither SWE nor MRE had sufficiently high positive predictive value to rule in advanced fibrosis.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00330-021-08369-9.

Transjugular liver biopsy and hepatic venous pressure gradient measurement in patients with and without liver cirrhosis

BACKGROUND

Transjugular liver biopsy (TJLB) and hepatic venous pressure gradient (HVPG) measurement are diagnostic procedures for patients with acute and chronic liver diseases. Technical execution of TJLB and HVPG may be challenging in patients with advanced liver disease.

OBJECTIVE

We studied consecutive TJLB and HVPG procedures and investigated technical success, complications, quality of biopsies, indications and treatment changes in patients with and without liver cirrhosis.

METHODS

In the study period from 2010 to 2018, 575 consecutive TJLB and HVPG procedures were analyzed. Demographic characteristics, procedure-related and follow-up data were extracted from medical records.

RESULTS

In total, 259 (45%) patients were diagnosed with liver cirrhosis whereas 316 (55%) patients had no evidence of advanced chronic liver disease. Technical success of TJLB was significantly higher in patients without liver cirrhosis (287; 92%) compared to patients with liver cirrhosis [184; 76.7% (P = 0.001)]. Technical success of HVPG measurement was not different between both groups (P = 0.553). Liver biopsy specimens were significantly shorter in patients with liver cirrhosis (P = 0.001). Medical therapy was adjusted in 163 (28.4%) patients. In patients with liver cirrhosis, results of TJLB led less frequently to therapy initiation or adjustment compared to patients without liver cirrhosis (P = 0.001). In multivariate analysis, liver cirrhosis (Exp(B) 1.866; P = 0.012), alanine aminotransferase (Exp(B) 0.248; P < 0.001) and INR (Exp(B) 0.583; P = 0.027) were independently associated with treatment change.

CONCLUSION

Technical success and therapeutic decisions of TJLB are directly linked to presence or absence of liver cirrhosis.

Cognitive Function, Sarcopenia, and Inflammation Are Strongly Associated with Frailty: A Framingham Cohort Study

BACKGROUND

Frailty is an important contributor to morbidity and mortality in chronic liver disease. Understanding the contributors to frailty has the potential to identify individuals at risk for frailty and may potentially provide targets for frailty-modifying interventions. We evaluated the relationship among cognitive function, inflammation, and sarcopenia and frailty.

METHODS

Using cohorts from the Framingham Heart Study (2011-2014), we evaluated for factors associated with frailty. Exposures included cognitive tests (combined Trails A/B test, Animal Naming Test, and combined Digit Span Forward/Backward test), inflammation (interleukin-6 and tumor necrosis factor receptor II), and sarcopenia (creatinine-to-cystatin C ratio). We performed linear and logistic regression to identify the relationship between these exposures and the Liver Frailty Index (LFI).

RESULTS

The study population (N = 1208) had a median age of 70 years, was 56% female, and 48.5% had evidence of liver disease. The combined Trails A/B test (β 0.05, P < .001), creatinine-to-cystatin C (β -0.17, P = .006), and both inflammatory markers, interleukin-6 levels (β 0.16, P = .002) and tumor necrosis factor receptor II (β 0.21, P = .04), were independently associated with the LFI. Using an LFI cutoff of ≥4.5 to define frailty, Trails A/B (odds ratio [OR] 1.21, 95% confidence interval [CI] 1.07-1.37), Animal Naming Test (OR 0.64, 95% CI 0.42-0.97), sarcopenia (OR 0.10, 95% CI 0.01-0.73), and interleukin-6 (OR 4.99, 95% CI 1.03-15.53) were all associated with frailty. Although liver disease did not modify the relationship between the LFI and the Trails A/B test, interleukin-6 was significantly associated with the LFI only in the presence of liver disease.

CONCLUSIONS

Cognitive performance, inflammation, and sarcopenia, each highly prevalent in cirrhosis, are associated with the LFI in this population-based study of persons without cirrhosis. Further research is warranted for interventions aiming to prevent frailty by tailoring their approach to the patient's underlying risk factors.

Hepatocellular carcinoma risk in hepatitis C stage-3 fibrosis after sustained virological response with direct-acting antivirals

BACKGROUND & AIMS

Patients with chronic hepatitis C and stage 3 fibrosis are thought to remain at risk of hepatocellular carcinoma after sustained virological response. We investigated this risk in a large cohort of patients with well-defined stage 3 fibrosis.

METHODS

We performed a multicentre, ambispective, observational study of chronic hepatitis C patients with sustained virological response after treatment with direct-acting antivirals started between January and December 2015. Baseline stage 3 was defined in a two-step procedure: we selected patients with transient elastography values of 9.5-14.5 kPa and subsequently excluded those with nodular liver surface, splenomegaly, ascites or collaterals on imaging, thrombopenia or esophago-gastric varices. Patients were screened twice-yearly using ultrasound.

RESULTS

The final sample comprised 506 patients (median age, 57.4 years; males, 59.9%; diabetes, 17.2%; overweight, 44.1%; genotype 3, 8.9%; HIV coinfection, 18.4%; altered liver values, 15.2%). Median follow-up was 33.7 (22.1-39.1) months. Five hepatocellular carcinomas and 1 cholangiocarcinoma were detected after a median of 29.4 months (95% CI: 26.8-39.3), with an incidence of 0.47/100 patients/year (95% CI: 0.17-1.01). In the multivariate analysis, only males older than 55 years had a significant higher risk (hazard ratio 7.2 [95% CI: 1.2-41.7; P = .029]) with an incidence of 1.1/100 patients/year (95% CI: 0.3-2.8).

CONCLUSIONS

In a large, well-defined cohort of patients with baseline hepatitis C stage-3 fibrosis, the incidence of primary liver tumours was low after sustained virological response and far from the threshold for cost-effectiveness of screening, except in males older than 55 years.

Role of endoscopic ultrasound in the field of hepatology: Recent advances and future trends

The role of endoscopic ultrasound (EUS) as a diagnostic and therapeutic modality for the management of various gastrointestinal diseases has been expanding. The imaging or intervention for various liver diseases has primarily been the domain of radiologists. With the advances in EUS, the domain of endosonologists is rapidly expanding in the field of hepatology. The ability to combine endoscopy and sonography in one hybrid device is a unique property of EUS, together with the ability to bring its probe/transducer near the liver, the area of interest. Its excellent spatial resolution and ability to provide real-time images coupled with several enhancement techniques, such as contrast-enhanced (CE) EUS, have facilitated the growth of EUS. The concept of "Endo-hepatology" encompasses the wide range of diagnostic and therapeutic procedures that are now gradually becoming feasible for managing various liver diseases. Diagnostic advancements can enable a wide array of techniques from elastography and liver biopsy for liver parenchymal diseases, to CE-EUS for focal liver lesions to portal pressure measurements for managing various liver conditions. Similarly, therapeutic advancements range from EUS-guided eradication of varices, drainage of bilomas and abscesses to various EUS-guided modalities of liver tumor management. We provide a comprehensive review of all the different diagnostic and therapeutic EUS modalities available for the management of various liver diseases. A synopsis of all the technical details involving each procedure and the available data has been tabulated, and the future trends in this area have been highlighted.

Initiation of hepatic stellate cell activation extends into chronic liver disease

Activated hepatic stellate cells (aHSC) are the main source of extra cellular matrix in liver fibrosis. Activation is classically divided in two phases: initiation and perpetuation. Currently, HSC-based therapeutic candidates largely focus on targeting the aHSCs in the perpetuation phase. However, the importance of HSC initiation during chronic liver disease (CLD) remains unclear. Here, we identified transcriptional programs of initiating and activated HSCs by RNA sequencing, using in vitro and in vivo mouse models of fibrosis. Importantly, we show that both programs are active in HSCs during murine and human CLD. In human cirrhotic livers, scar associated mesenchymal cells employ both transcriptional programs at the single cell level. Our results indicate that the transcriptional programs that drive the initiation of HSCs are still active in humans suffering from CLD. We conclude that molecules involved in the initiation of HSC activation, or in the maintenance of aHSCs can be considered equally important in the search for druggable targets of chronic liver disease.

Progression of Prothrombin Induced by Vitamin K Absence-II in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer and the third leading cause of cancer-related death worldwide. Due to the lack of efficient tools for early detection, asymptomatic HCC patients are diagnosed at an advanced stage, leading to a poor prognosis. To improve survival, serum biomarker prothrombin induced by vitamin K absence-II (PIVKA-II) was under investigation. PIVKA-II is an abnormal protein produced in HCC. The coagulation function was insufficient due to the lack of Gla residues. Elevated PIVKA-II was associated with bad tumor behavior in terms of proliferation, metastasis, and invasion. Three major signaling pathways were proposed to clarify the mechanism. With the advantages including affordability, minimal invasiveness, convenience, and efficiency, PIVKA-II could improve HCC management consisting of four aspects. First, PIVKA-II was an effective and dynamic tool for improving HCC surveillance in high-risk population. Changes in the serum levels of PIVKA-II provided valuable molecular alteration information before imaging discovery. Second, PIVKA-II offered a complementary approach for HCC early detection. Compared to traditional diagnostic approaches, the combination of PIVKA-II and other biomarkers had better performance. Third, PIVKA-II was an indicator for the assessment of response to treatment in HCC. Preoperative assessment was for selecting personalized therapy, and postoperative measurement was for assessing treatment efficacy. Fourth, PIVKA-II was considered as a prognostic predictor for HCC. Patients with elevated PIVKA-II were more likely to develop microvascular invasion, metastasis, and recurrence.

Artificial Intelligence in Hepatology: A Narrative Review

There has been a tremendous growth in data collection in hepatology over the last decade. This wealth of "big data" lends itself to the application of artificial intelligence in the development of predictive and diagnostic models with potentially greater accuracy than standard biostatistics. As processing power of computing systems has improved and data are made more accessible through the large databases and electronic health record, these more contemporary techniques for analyzing and interpreting data have garnered much interest in the field of medicine. This review highlights the current evidence base for the use of artificial intelligence in hepatology, focusing particularly on the areas of diagnosis and prognosis of advanced chronic liver disease and hepatic neoplasia.

Deep Learning Prediction of Voxel-Level Liver Stiffness in Patients with Nonalcoholic Fatty Liver Disease

PURPOSE

To reconstruct virtual MR elastography (MRE) images based on traditional MRI inputs with a machine learning algorithm.

MATERIALS AND METHODS

In this single-institution, retrospective study, 149 patients (mean age, 58 years ± 12 [standard deviation]; 71 men) with nonalcoholic fatty liver disease who underwent MRI and MRE between January 2016 and January 2019 were evaluated. Nine conventional MRI sequences and clinical data were used to train a convolutional neural network to reconstruct MRE images at the per-voxel level. The architecture was further modified to accept multichannel three-dimensional inputs and to allow inclusion of clinical and demographic information. Liver stiffness and fibrosis category (F0 [no fibrosis] to F4 [significant fibrosis]) of reconstructed images were assessed by using voxel- and patient-level agreement by correlation, sensitivity, and specificity calculations; in addition, classification by receiver operator characteristic analyses was performed, and Dice score was used to evaluate hepatic stiffness locality.

RESULTS

The model for predicting liver stiffness incorporated four image sequences (precontrast T1-weighted liver acquisition with volume acquisition [LAVA] water and LAVA fat, 120-second-delay T1-weighted LAVA water, and single-shot fast spin-echo T2 weighted) and clinical data. The model had a patient-level and voxel-level correlation of 0.50 ± 0.05 and 0.34 ± 0.03, respectively. By using a stiffness threshold of 3.54 kPa to make a binary classification into no fibrosis or mild fibrosis (F0-F1) versus clinically significant fibrosis (F2-F4), the model had sensitivity of 80% ± 4, specificity of 75% ± 5, accuracy of 78% ± 3, area under the receiver operating characteristic curve of 84 ± 0.04, and a Dice score of 0.74.

CONCLUSION

The generation of virtual elastography images is feasible by using conventional MRI and clinical data with a machine learning algorithm.Keywords: MR Imaging, Abdomen/GI, Liver, Cirrhosis, Computer Applications/Virtual Imaging, Experimental Investigations, Feature Detection, Classification, Reconstruction Algorithms, Supervised Learning, Convolutional Neural Network (CNN) Supplemental material is available for this article. © RSNA, 2021.

Advanced liver fibrosis and the metabolic syndrome in a primary care setting

AIMS

The fibrosis-4 index (FIB-4) and NAFLD fibrosis score (NFS) are noninvasive and accessible methods for assessing advanced liver fibrosis risk in primary care. We evaluated the distribution of FIB-4 and NFS scores in primary care patients with clinical signals for nonalcoholic fatty liver disease (NAFLD).

MATERIALS AND METHODS

This retrospective cohort study of electronic record data between 2007 and 2018 included adults with at least one abnormal aminotransferase and no known (non-NAFLD) liver disease. We calculated patient-level FIB-4 and NFS scores, the proportion of patients with mean values exceeding advanced fibrosis thresholds (indeterminate risk: FIB-4 > 1.3, NFS > -1.455; high-risk: FIB-4 > 2.67, NFS > 0.676), and the proportion of patients with a NAFLD International Classification of Diseases-9/10 code. Logistic regression models evaluated the associations of metabolic syndrome (MetS) components with elevated FIB-4 and NFS scores.

RESULTS

The cohort included 6506 patients with a median of 6 (interquartile range: 3-13) FIB-4 and NFS scores per patient. Of these patients, 81% had at least two components of MetS, 29% had mean FIB-4 and NFS scores for indeterminate fibrosis risk, and 11% had either mean FIB-4 or NFS scores exceeding the high advanced fibrosis risk thresholds. Regression models identified associations of low high-density lipoprotein, hyperglycemia, Black race and male gender with high-risk FIB-4 and NFS values. Only 5% of patients had existing diagnoses for NAFLD identified.

CONCLUSIONS

Many primary care patients have FIB-4 and NFS scores concerning for advanced fibrosis, but rarely a diagnosis of NAFLD. Elevated FIB-4 and NFS scores may provide signals for further clinical evaluation of liver disease in primary care settings.

Quantification of Liver Fat Content with CT and MRI: State of the Art

Hepatic steatosis is defined as pathologically elevated liver fat content and has many underlying causes. Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide, with an increasing prevalence among adults and children. Abnormal liver fat accumulation has serious consequences, including cirrhosis, liver failure, and hepatocellular carcinoma. In addition, hepatic steatosis is increasingly recognized as an independent risk factor for the metabolic syndrome, type 2 diabetes, and, most important, cardiovascular mortality. During the past 2 decades, noninvasive imaging-based methods for the evaluation of hepatic steatosis have been developed and disseminated. Chemical shift-encoded MRI is now established as the most accurate and precise method for liver fat quantification. CT is important for the detection and quantification of incidental steatosis and may play an increasingly prominent role in risk stratification, particularly with the emergence of CT-based screening and artificial intelligence. Quantitative imaging methods are increasingly used for diagnostic work-up and management of steatosis, including treatment monitoring. The purpose of this state-of-the-art review is to provide an overview of recent progress and current state of the art for liver fat quantification using CT and MRI, as well as important practical considerations related to clinical implementation.