Liver ultrasound elastography: More than staging the disease

Novel noninvasive indices for the assessment of liver fibrosis in primary biliary cholangitis

The present study aimed to investigate the accuracy of new noninvasive markers in predicting liver fibrosis among individuals with primary biliary cholangitis (PBC). This retrospective analysis included subjects with PBC who had liver biopsies. Scheuer's classification was used to determine the fibrosis stage. The bilirubin to albumin (Alb) ratio (BAR), fibrosis index based on the four factors (FIB-4), γ-glutamyl transpeptidase to platelet (PLT) ratio (GPR), red cell distribution width to PLT ratio (RPR), aspartate aminotransferase (AST) to alanine aminotransferase ratio (AAR), AST to PLT ratio index (APRI) and total bilirubin to PLT ratio (TPR) were calculated based on the laboratory parameters. A novel index called BARP was conceived as BAR x RPR. A total of 78 individuals with PBC were included in the study, 84.6% of whom had significant fibrosis, 30.8% had advanced fibrosis and 15.4% had cirrhosis. In the multivariate analysis, Alb was determined to be an independent predictor of advanced fibrosis (odds ratio=0.823, P=0.034). The area under the receiver operating characteristic curves (AUROCs) of the BAR, GPR, TPR and BARP were statistically significant in predicting severe fibrosis (P<0.05) and were 0.747, 0.684, 0.693 and 0.696, respectively. In assessing advanced fibrosis, the AUROCs for the AAR, APRI, BAR, FIB-4, RPR, TPR and BARP were 0.726, 0.650, 0.742, 0.716, 0.670, 0.735 and 0.750, respectively. The AUROCs for the APRI, BAR, FIB-4, RPR, TPR and BARP for cirrhosis prediction were 0.776, 0.753, 0.821, 0.819, 0.808 and 0.832, respectively. By comparing the AUROCs, it was demonstrated that the diagnostic capabilities of the BARP (P=0.021) and TPR (P=0.044) were superior to those of the APRI in predicting advanced fibrosis. In conclusion, the BAR, BARP and TPR were of predictive value for the grade of liver fibrosis in PBC and Alb had a diagnostic value in identifying early fibrosis. The aforementioned noninvasive indices may be used for predicting histologic stages of PBC.

The Role of Endoscopic Ultrasound in Hepatology

Endoscopic ultrasound (EUS) has been an indispensable and widely used diagnostic tool in several medical fields, including gastroenterology, cardiology, and urology, due to its diverse therapeutic and diagnostic applications. Many studies show that it is effective and safe in patients with liver conditions where conventional endoscopy or cross-sectional imaging are inefficient or when surgical interventions pose high risks. In this article, we present a review of the current literature for the different diagnostic and therapeutic applications of EUS in liver diseases and their complications and discuss the potential future application of artificial intelligence analysis of EUS.

Applications of elastography in operative neurosurgery: A systematic review

Elastography is an imaging technology capable of measuring tissue stiffness and consistency. The technology has achieved widespread use in the workup and management of diseases of the liver, breast, thyroid, and prostate. Although elastography is increasingly being applied in neurosurgery, it has not yet achieved widespread adoption and many clinicians remain unfamiliar with the technology. Therefore, we sought to summarize the range of applications and elastography modalities available for neurosurgery, report its effectiveness in comparison with conventional imaging methods, and offer recommendations. All full-text English-language manuscripts on the use of elastography for neurosurgical procedures were screened using the PubMed/MEDLINE, Embase, Cochrane Library, Scopus, and Web of Science databases. Thirty-two studies were included with 990 patients, including 21 studies on intracranial tumors, 5 on hydrocephalus, 4 on epilepsy, 1 on spinal cord compression, and 1 on adolescent scoliosis. Twenty studies used ultrasound elastography (USE) whereas 12 used magnetic resonance elastography (MRE). MRE studies were mostly used in the preoperative setting for assessment of lesion stiffness, tumor-brain adherence, diagnostic workup, and operative planning. USE studies were performed intraoperatively to guide resection of lesions, determine residual microscopic abnormalities, assess the tumor-brain interface, and study mechanical properties of tumors. Elastography can assist with resection of brain tissue, detection of microscopic lesions, and workup of hydrocephalus, among other applications under investigation. Its sensitivity often exceeds that of conventional MRI and ultrasound for identifying abnormal tissue and lesion margins.

Defining values for controlled attenuation parameter and liver stiffness in youth without liver disease

BACKGROUND

We aimed to determine the reference values to define an age-specific normal range of controlled attenuation parameter (CAP, a measure of liver steatosis) and liver stiffness measurement (LSM) values assessed by ultrasound-based transient elastography in adolescents without underlying liver disease.

METHODS

A total of 462 participants were included in this cross-sectional study using data from NHANES 2017-2018. LSM and CAP were carried out using the FibroScan® M-probe. Anthropometric, metabolic and hematological parameters were measured.

RESULTS

The median CAP was 199.0 dB/m (150.0-245.0 dB/m, 10th to 90th percentiles) and the median LSM was 4.7 kPa (3.4-6.3 kPa, 10th to 90th percentiles) for ages 12-19.9 years. Regression analyses show that the CAP and LSM were not positively correlated with age (boys CAP R² = 0.001, p = 0.576 and LSM R² = 0.012, p = 0.096; girls CAP R² = 0.011, p = 0.113 and LSM R² = 0.006, p = 0.236). Finally, CAP was positively associated with LSM in girls (β = 0.189, p = 0.005) but not in boys (β = -0.083, p = 0.202).

CONCLUSIONS

The reference values indicated here for LSM and CAP will help in the screening of adolescents between ages 12 and 19.9 years and might serve as a useful method for identifying those youth at high risk of nonalcoholic fatty liver disease.

IMPACT

The reference values indicated in this study for liver stiffness measurement (LSM) and controlled attenuation parameter (CAP) will help in the screening of adolescents between ages 12 and 19.9 years in clinical practice. The cutoffs of LSM and CAP might serve as a useful method for identifying those youth at high risk of nonalcoholic fatty liver disease.

Entecavir resistance in a patient with treatment-naïve HBV: A case report

Among nucleos(t)ide analogue therapies for hepatitis B virus (HBV) treatment, entecavir (ETV) and tenofovir disoproxil fumarate (TDF)/tenofovir alafenamide are associated with the lowest rate of drug resistance. ETV is a drug requiring at least three substitutions in the reverse transcriptase (RT) domain to develop resistance, which is a rare occasion in treatment-naïve patients. However, pre-existing or acquired single mutations in the RT domain could lead to a virological breakthrough, after viral suppression. The present case report describes a 58-year-old female patient with hepatitis B virus (HBV) and high viral load who started HBV treatment with ETV. After 85 weeks of treatment, HBV-DNA declined to 0 IU/ml and remained undetectable for 3 years. However, after that period of time, the HBV-DNA rebounded, followed by the rise of liver enzymes (aspartate aminotransferase and alanine transaminase). Only the substitution M204I was detected in the HBV polymerase region. The patient was then switched to TDF treatment, achieving normalization of the liver enzymes and a decline in HBV-DNA levels. The present case report suggests that nucleoside-naïve patients should be cautiously monitored for resistance, even more than biochemically (transaminases, bilirubin) and virologically (HBV-DNA), even if complete HBV suppression is achieved.

The liver matrisome - looking beyond collagens

The extracellular matrix (ECM) is a diverse microenvironment that maintains bidirectional communication with surrounding cells to regulate cell and tissue homeostasis. The classical definition of the ECM has more recently been extended to include non-fibrillar proteins that either interact or are structurally affiliated with the ECM, termed the 'matrisome.' In addition to providing the structure and architectural support for cells and tissue, the matrisome serves as a reservoir for growth factors and cytokines, as well as a signaling hub via which cells can communicate with their environment and vice-versa. The matrisome is a master regulator of tissue homeostasis and organ function, which can dynamically and appropriately respond to any stress or injury. Failure to properly regulate these responses can lead to changes in the matrisome that are maladaptive. Hepatic fibrosis is a canonical example of ECM dyshomeostasis, leading to accumulation of predominantly collagenous ECM; indeed, hepatic fibrosis is considered almost synonymous with collagen accumulation. However, the qualitative and quantitative alterations of the hepatic matrisome during fibrosis are much more diverse than simple accumulation of collagens and occur long before fibrosis is histologically detected. A deeper understanding of the hepatic matrisome and its response to injury could yield new mechanistic insights into disease progression and regression, as well as potentially identify new biomarkers for both. In this review, we discuss the role of the ECM in liver diseases and look at new "omic" approaches to study this compartment.

Study protocol for a 9-month randomised controlled trial assessing the effects of almonds versus carbohydrate-rich snack foods on weight loss and weight maintenance

INTRODUCTION

Epidemiological studies indicate an inverse association between nut consumption and body mass index (BMI). However, clinical trials evaluating the effects of nut consumption compared with a nut-free diet on adiposity have reported mixed findings with some studies reporting greater weight loss and others reporting no weight change. This paper describes the rationale and detailed protocol for a randomised controlled trial assessing whether the inclusion of almonds or carbohydrate-rich snacks in an otherwise nut-free energy-restricted diet will promote weight loss during 3 months of energy restriction and limit weight regain during 6 months of weight maintenance.

METHODS AND ANALYSIS

One hundred and thirty-four adults aged 25-65 years with a BMI of 27.5-34.9 kg/m² will be recruited and randomly allocated to either the almond-enriched diet (AED) (15% energy from almonds) or a nut-free control diet (NFD) (15% energy from carbohydrate-rich snack foods). Study snack foods will be provided. Weight loss will be achieved through a 30% energy restriction over 3 months, and weight maintenance will be encouraged for 6 months by increasing overall energy intake by ~120-180 kcal/day (~500-750kJ/day) as required. Food will be self-selected, based on recommendations from the study dietitian. Body composition, resting energy expenditure, total daily energy expenditure (via doubly labelled water), physical activity, appetite regulation, cardiometabolic health, gut microbiome, liver health, inflammatory factors, eating behaviours, mood and personality, functional mobility and pain, quality of life and sleep patterns will be measured throughout the 9-month trial. The effects of intervention on the outcome measures over time will be analysed using random effects mixed models, with treatment (AED or NFD) and time (baseline, 3 months and 9 months) being the between and within factors, respectively in the analysis.

ETHICS AND DISSEMINATION

Ethics approval was obtained from the University of South Australia Human Research Ethics Committee (201436). Results from this trial will be disseminated through publication in peer-reviewed journals, national and international presentations.

TRIAL REGISTRATION NUMBER

Australian New Zealand Clinical Trials Registry (ACTRN12618001861246).

Endoscopic ultrasound in chronic liver disease

Endoscopic ultrasound (EUS) is a minimally invasive diagnostic and therapeutic modality with a number of established as well as evolving uses in patients with chronic liver disease. Compared to other diagnostic tools such as cross-sectional imaging or conventional endoscopy, EUS has been shown to increase diagnostic sensitivity and therapeutic success for many clinical scenarios and applications with a low rate of adverse events. In this review, we discuss and focus on the current and growing role of EUS in the evaluation and/or treatment of hepatobiliary masses, hepatic parenchymal disease, portal hypertension, esophageal and other varices, and indeterminate biliary strictures.

Reference values of normal liver stiffness in healthy children by two methods: 2D shear wave and transient elastography

TE and 2D-SWE are well-documented in studies performed on adults, but those on pediatric patients are limited. The aim of this study was to establish pediatric reference values for liver stiffness using two elastography methods: 2D-SWE and TE. We performed an observational study on 206 healthy children. All children underwent anamnesis, clinical exam, laboratory tests, US exam, TE and 2D-SWE for liver stiffness assessment. The mean liver stiffness value by 2D-SWE for all children was 3.72 ± 0.48 kPa. The mean values ranged between 3.603 ± 0.2678 kPa (3–5 years of age) and 3.774 ± 0.4038 kPa (9–11 years). The reference values varied between 4.1386 kPa (3–5 years of age) and 4.88 kPa (12–15 years). The mean liver stiffness value by TE was 3.797 ± 0.4859 kPa. The values ranged between 3.638 ± 0.4088 kPa (6–8 years of age) and 3.961 ± 0.5695 kPa (15–18 years). The cutoff values varied from 4.4064 kPa (3–5 years of age) to 5.1 kPa (15–18 years). We found a significant positive correlation between E Median values by TE and age [95% CI: 0.1160 to 0.3798, r = 0.2526, p = 0.0002]. Our findings revealed that the mean values of liver stiffness for all children on 2D-SWE and TE were almost identical, 3.72 ± 0.48 kPa versus 3.797 ± 0.4859 kPa.

Transient Elastography with Serum Hepatitis B Surface Antigen Enhances Liver Fibrosis Detection

BACKGROUND The aim of this study was to explore transient elastography (TE) with quantitative hepatitis B surface antigen (qHBsAg) for detecting advanced hepatic fibrosis. MATERIAL AND METHODS This was a single-center prospective real-life analysis of 111 treatment-naïve chronic hepatitis B (CHB) patients enrolled into the Establishment of Non-invasive Diagnosis Criteria and Model of Hepatitis B Virus-related Cirrhosis Study. RESULTS There were significant correlations between TE, qHBsAg, and fibrosis. Both qHBsAg and TE were identified as independent predictors for advanced fibrosis. In receiver operating characteristic curve (ROC) analysis, TEqHBsAg (combination of TE and qHBsAg) resulted in the highest area under the receiver-operator curve (AUC) (0.912), mainly due to increased specificity. Using the optimal cut-off, TEqHBsAg provided a sensitivity of 86.7%, and increased specificity from 78.7% to 85.1%. CONCLUSIONS Combining TE with qHBsAg enhances specificity in identifying advanced fibrosis in treatment-naïve CHB patients.

Does motion affect liver stiffness estimates in shear wave elastography? Phantom and clinical study

This study was undertaken to evaluate the impact of free-breathing (FB) vs. Apnea on Shear-wave elastography (SWE) measurements. Quantitative liver-stiffness measurements were obtained during FB and Apnea for 97 patients with various body-morphologies and liver textures. Quality indexes of FB and Apnea elasticity maps (percentage of non-filling (PNF), temporal (TV) and spatial (SV) variabilities) were computed. SWE measurements were also obtained from an homogeneous phantom at rest and during a mechanically-induced motion. Liver-stiffness values estimated from FB and Apnea acquisitions were correlated, particularly for homogeneous livers (r=0.76, P<0.001) and favorable body-morphologies (r=0.68, P<0.001). However FB values were consistently 20-25% lower than Apnea ones (P<0.001). FB also systematically resulted in degradation of TV (P<0.005) and PNF (P<0.001) compared to Apnea but had no impact on SV. With the phantom, no differences between SWE measurements at rest and during motion were observed. Apnea and FB measurements are highly correlated, although FB data quality is degraded compared to Apnea and estimated stiffness in FB is systematically lower than in Apnea. These discrepancies between rest and motion states were observed for patients but not for phantom data, suggesting that patient breath-holding impacts liver stiffness.

Assessment of liver fibrosis using pharmacokinetic parameters of dynamic contrast-enhanced magnetic resonance imaging

PURPOSE

To evaluate the pharmacokinetic parameters of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in diagnosing and staging liver fibrosis in rabbits.

MATERIALS AND METHODS

DCE-MRI with gadodiamide (Gd-DTPA-BMA) was performed on a 3.0 Tesla, 60 cm bore MR scanner for rabbits with CCl4 -induced liver fibrosis, and an untreated control group. Fibrosis was staged according to the METAVIR system: control (F0; n = 13), nonadvanced fibrosis (F1-2; n = 15), and advanced fibrosis (F3-4; n = 12). The DCE-MRI parameters K(trans) , kep , Ve , and vp were measured with a dual-input extended Tofts model. Receiver operating characteristic analyses were performed to assess the diagnostic performance of K(trans) , Ve , and vp in staging liver fibrosis.

RESULTS

Both K(trans) and Ve decreased with increasing fibrosis stage. K(trans) of the control group was significantly different from that of the overall fibrosis group, nonadvanced group, and advanced group (P < 0.001 for all). Significant differences were found between Ve of the control group and that of the overall fibrosis and advanced groups (P = 0.019 and P = 0.009, respectively). For K(trans) , the areas under the receiver operating characteristic curve (AUROCs) for discriminating the control group from the overall fibrosis and advanced fibrosis groups were 0.909 (95% confidence interval [CI], 0.809-1.000), and 0.936 (95% CI,0.847-1.000), respectively. For discriminating between the control and nonadvanced fibrosis groups, the AUROC of K(trans) was 0.887 (95% CI, 0.762-1.000). The AUROCs of K(trans) were higher than those of Ve and vp for discriminating between the control and overall fibrosis groups, the control and nonadvanced fibrosis groups, and the control and advanced fibrosis groups. Pharmacokinetic parameters were negatively correlated with fibrosis stage (K(trans) , rho = -0.668, P < 0.001; Ve , rho = -0.438, P = 0.005; vp , rho = -0.360, P = 0.023).

CONCLUSION

Among pharmacokinetic parameters of DCE-MRI in our study, K(trans) was an excellent predictor for differentiating fibrotic livers from normal livers, and differentiating normal livers from nonadvanced or advanced fibrosis livers. J. Magn. Reson. Imaging 2016;44:98-104.