Update on ultrasound imaging of liver fibrosis

Non-invasive screening for liver fibrosis by acoustic radiation force impulse in patients with ciliopathies

Primary cilia are antenna-like structures on the surface of epithelial cells involved in multiple signaling pathways. Their malfunction can cause a heterogenous group of diseases called ciliopathies with a broad spectrum of organ involvements, including liver fibrosis. The aim of this exploratory study was to evaluate elastography measurement via ultrasound based acoustic radiation force impulse imaging (ARFI) as a screening tool for liver fibrosis in ciliopathies. In a prospective cohort of 51 patients with ciliopathies (aged between 2 months and 66 years) from the NEOCYST registry stiffness of the right liver lobe and spleen was measured via ARFI and results were then compared with laboratory parameters, endoscopic, ultrasonographic and histological findings. ARFI screening of the liver identified 27 patients without increased liver stiffness suggesting no or insignificant fibrosis, 11 with intermediate fibrosis, and 12 with liver fibrosis F4. Four patients showed increased spleen stiffness in ARFI. In all 10 patients with histologically confirmed fibrosis, ARFI results perfectly matched fibrosis stages. In the ARFI-based overall fibrosis subgroup, ALT, AST, GGT and spleen size were significantly increased, whereas platelets were significantly decreased compared to the no fibrosis subgroup. Normal GGT excluded ARFI-defined F4 fibrosis (negative predictive value 100%). Gene variants in PKHD1, TMEM67, and TULP3 were primarily detected in our patients with liver fibrosis whereas NPHP1 and HNF1B were not associated with increased liver stiffness. ARFI is a valuable screening tool for the detection of liver involvement in ciliopathies and may be useful in addition to laboratory and clinical parameters alone.Trial registration: NEOCYST registry DRKS00011003, registered 06.09.2016, https://drks.de/search/en/trial/DRKS00011003 .

Ultrasonic Assessment of Liver Fibrosis Using One-Dimensional Convolutional Neural Networks Based on Frequency Spectra of Radiofrequency Signals with Deep Learning Segmentation of Liver Regions in B-Mode Images: A Feasibility Study

The early detection of liver fibrosis is of significant importance. Deep learning analysis of ultrasound backscattered radiofrequency (RF) signals is emerging for tissue characterization as the RF signals carry abundant information related to tissue microstructures. However, the existing methods only used the time-domain information of the RF signals for liver fibrosis assessment, and the liver region of interest (ROI) is outlined manually. In this study, we proposed an approach for liver fibrosis assessment using deep learning models on ultrasound RF signals. The proposed method consisted of two-dimensional (2D) convolutional neural networks (CNNs) for automatic liver ROI segmentation from reconstructed B-mode ultrasound images and one-dimensional (1D) CNNs for liver fibrosis stage classification based on the frequency spectra (amplitude, phase, and power) of the segmented ROI signals. The Fourier transform was used to obtain the three kinds of frequency spectra. Two classical 2D CNNs were employed for liver ROI segmentation: U-Net and Attention U-Net. ROI spectrum signals were normalized and augmented using a sliding window technique. Ultrasound RF signals collected (with a 3-MHz transducer) from 613 participants (Group A) were included for liver ROI segmentation and those from 237 participants (Group B) for liver fibrosis stage classification, with a liver biopsy as the reference standard (Fibrosis stage: F0 = 27, F1 = 49, F2 = 51, F3 = 49, F4 = 61). In the test set of Group A, U-Net and Attention U-Net yielded Dice similarity coefficients of 95.05% and 94.68%, respectively. In the test set of Group B, the 1D CNN performed the best when using ROI phase spectrum signals to evaluate liver fibrosis stages ≥F1 (area under the receive operating characteristic curve, AUC: 0.957; accuracy: 89.19%; sensitivity: 85.17%; specificity: 93.75%), ≥F2 (AUC: 0.808; accuracy: 83.34%; sensitivity: 87.50%; specificity: 78.57%), and ≥F4 (AUC: 0.876; accuracy: 85.71%; sensitivity: 77.78%; specificity: 94.12%), and when using the power spectrum signals to evaluate ≥F3 (AUC: 0.729; accuracy: 77.14%; sensitivity: 77.27%; specificity: 76.92%). The experimental results demonstrated the feasibility of both the 2D and 1D CNNs in liver parenchyma detection and liver fibrosis characterization. The proposed methods have provided a new strategy for liver fibrosis assessment based on ultrasound RF signals, especially for early fibrosis detection. The findings of this study shed light on deep learning analysis of ultrasound RF signals in the frequency domain with automatic ROI segmentation.

Liver dysfunction in adults with COVID-19 infection: A longitudinal study with transient elastography evaluation

Background and Aim

Abnormal liver biochemistry (ALB) is common among patients with COVID-19 infection due to various factors. It is uncertain if it persists after the acute infection. We aimed to investigate this.

Methods

A multicenter study of adult patients hospitalized for COVID-19 infection, with at least a single abnormal liver function test, was conducted. Detailed laboratory and imaging tests, including transabdominal ultrasound and FibroScan, were performed at assessment and at 6-month follow-up after hospital discharge.

Results

From an initial cohort of 1246 patients who were hospitalized, 731 (58.7%) had ALB. A total of 174/731 patients fulfilled the inclusion criteria with the following characteristics: 48.9% patients had severe COVID-19; 62.1% had chronic liver disease (CLD); and 56.9% had metabolic-associated fatty liver disease (MAFLD). ALB was predominantly of a mixed pattern (67.8%). Among those (55.2%) who had liver injury (aspartate aminotransferase/alanine aminotransferase >3 times the upper limit of normal, or alkaline phosphatase/γ-glutamyl transferase/bilirubin >2 times the upper limit of normal), a mixed pattern was similarly predominant. Approximately 52.3% had normalization of the liver lunction test in the 6-month period post discharge. Patients with persistent ALB had significantly higher mean body mass index (BMI) and serum low-density lipoprotein (LDL), higher rates of MAFLD and CLD, higher mean liver stiffness measurement and continuous attenuated parameter score on FibroScan, and higher rates of liver injury on univariate analysis. Multivariate analysis was not statistically significant.

Conclusions

Approximately 47.7% of COVID-19 patients were found to have persistent ALB up to 6 months following the acute infection, and it was associated with raised BMI, elevated serum LDL, increased rates of MAFLD and CLD, and higher rates of liver injury on univariate analysis, but not on multivariate analysis.

Ultrasound imaging findings in primary biliary cholangitis

BACKGROUND

Our study aimed to analyze the characteristics of ultrasound images corresponding to each histological stage of primary biliary cholangitis (PBC).

METHODS

We prospectively analyzed 75 confirmed cases of PBC and used liver biopsy as the gold standard to determine the disease stage.

RESULTS

The typical ultrasound images of patients with PBC were characterized by a thickening of the portal vein wall (PVW) and periportal hypoechoic band (PHB) width with increasing histological stages, and significant increases in the left hepatic lobe diameter (LHLD) in stage II (by 64.0%) and stage III (by 69.2%). PHB width (r = 0.857, p < 0.001), PVW thickness (r = 0.488, p < 0.001), and spleen area (r = 0.8774, p < 0.001) were positively correlated with the histological stage. Significant changes were noted in the liver surface, echo texture, and edge between different stages. The areas under the receiver operating characteristic curve of composite indicators were 0.965 for predicting progressive PBC(≥ stage 2), and 0.926 for predicting advanced PBC(≥ stage 3).

CONCLUSIONS

The ultrasound imaging characteristics of patients with PBC varied according to the histological staging. LHLD, PVW thickness, and PHB width were significantly correlated with the histological stage. A combination of high- and low-frequency ultrasound imaging can provide relevant cues regarding the degree of PBC progression and important clinical reference values. The application of all the ultrasound image findings as the composite indicators can better predict progressive and advanced PBC, providing important clinical reference values.

Chinese herbal formula ruangan granule enhances the efficacy of entecavir to reverse advanced liver fibrosis/early cirrhosis in patients with chronic HBV infection: A multicenter, randomized clinical trial

BACKGROUND

Nucleotide analogs treatment can reverse liver fibrosis in chronic hepatitis B (CHB). However, it has limited effect on fibrosis resolution in patients with CHB, particularly in preventing progression to hepatocellular carcinoma (HCC). Ruangan granule (RG), a Chinese herbal formula, has proven to produce a therapeutic effect against liver fibrosis in animal experiment. Thus, we aimed to evaluate the effect of our Chinese herbal formula (RG) combined with entecavir (ETV) to reverse advanced liver fibrosis/early cirrhosis from CHB.

METHODS

A total of 240 CHB patients with histologically confirmed advanced liver fibrosis/early cirrhosis from 12 centers were randomly and blindly allocated to consume either ETV (0.5 mg/day) plus RG (2 times/day) or control (ETV) for 48 weeks (wk) treatment. Changes in histopathology, serology and imageology were observed. Liver fibrosis reversion, defined as a reduction in the Knodell HAI score by ≥ 2 points and Ishak score by ≥ 1 grade, was assessed.

RESULTS

The rate of fibrosis regression and inflammation remission after 48 wk of treatment in histopathology was significantly higher in the ETV + RG group (38.73% vs. 23.94%, P = 0.031). The ultrasonic semiquantitative scores decreased by ≥ 2 points and were 41 (28.87%) and 15 (21.13%) in the ETV+RG and ETV groups, respectively (P = 0.026). The ETV+RG group had a significantly lower Fibrosis-4 score (FIB-4) index (P = 0.028). There was a significant difference between the ETV+RG and ETV groups in the liver function normalization rate (P < 0.01). Moreover, ETV plus RG combination treatment further reduced the risk of HCC in median 55-month follow-up (P < 0.01).

CONCLUSIONS

This study illustrates that the Chinese herbal formula RG with ETV can improve advanced liver fibrosis/early cirrhosis regression in patients with CHB, further reducing the risk of HCC.

Image Human Thorax Using Ultrasound Traveltime Tomography with Supervised Descent Method

The change of acoustic velocity in the human thorax reflects the functional status of the respiratory system. Imaging the thorax’s acoustic velocity distribution can be used to monitor the respiratory system. In this paper, the feasibility of imaging the human thorax using ultrasound traveltime tomography with a supervised descent method (SDM) is studied. The forward modeling is computed using the shortest path ray tracing (SPR) method. The training model is composed of homogeneous acoustic velocity background and a high-velocity rectangular block moving in the domain of interest (DoI). The average descent direction is learned from the training set. Numerical experiments are conducted to verify the method’s feasibility. Normal thorax model experiment proves that SDM traveltime tomography can efficiently reconstruct thorax acoustic velocity distribution. Numerical experiments based on synthetic thorax model of pleural effusion and pneumothorax show that SDM traveltime tomography has good generalization ability and can detect the change of acoustic velocity in human thorax. This method might be helpful for the diagnosis and evaluation of respiratory diseases.

Tenofovir vs. Entecavir on Outcomes of Hepatitis B Virus-Related Hepatocellular Carcinoma after Radiofrequency Ablation

For patients with hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) treated with curative radiofrequency ablation (RFA), the effect of entecavir (ETV) vs. tenofovir disoproxil fumarate (TDF) on recurrence-free survival (RFS) and overall survival (OS) remains unclear. We aimed to compare the outcomes of patients receiving ETV or TDF after RFA. This study consecutively collected patients who were treated with ETV (n = 202) or TDF (n = 102) for chronic hepatitis B (CHB) after curative RFA of HCC from December 2015 to January 2021 at Sun Yat-sen University Cancer Center. There were 130 patients in the ETV group and 77 patients in the TDF group after we performed 1-to-n propensity score matching. Kaplan−Meier and Cox regression analyses were performed to validate possible risk factors for RFS and OS. In addition, we estimated the curative effect of ETV and TDF for HBV-related hepatitis by recording the change in serum HBV DNA and ALBI grade after RFA. During the study period (median 34.1 (interquartile range: 19.6−47.4 months) months), 123 (40.5%) patients suffered HCC recurrence, and 15 (4.9%) died. In the full cohort, the probability of HCC recurrence (41.6% vs. 37.3%, p = 0.49) and overall survival (95% vs. 95.1%, p = 0.39) at 5 years were similar between the ETV and TDF groups. In the matched cohort, HCC recurrence (40.8% vs. 40.3%, p = 0.35) and overall survival (96.9% vs. 93.5%, p = 0.12) at 5 years were similar between the ETV and TDF groups. Furthermore, the early RFS (<2 years) did not differ significantly between the two groups in the full and matched cohorts (p = 0.26, p = 0.13). Compared with the ALBI grade before RFA, the ALBI grade of 80 patients (41%) remained stable or improved in the ETV group and 64 patients (64%) in the TDF group (p < 0.001). The mean time of serum HBV DNA reduction to 0 was 9.13 (95% CI: 5.92−12.33) and 2.75 (95% CI: 2.01−3.49) months in the ETV and TDF groups, respectively (p = 0.015). The RFS and OS of patients after curative RFA for HCC were not significantly different between the ETV and TDF groups. TDF therapy was associated with a better effect of protecting liver function and reducing the load of HBV. Further validation studies are needed.

Texture Analysis of Gray-Scale Ultrasound Images for Staging of Hepatic Fibrosis

Purpose

Materials and Methods

Results

Conclusion

Chronic genotype 1 hepatitis C along with cirrhosis drives a persistent imprint in virus-specific CD8+ T cells after direct-acting antiviral therapies

Chronic hepatitis C virus (HCV) infection impairs HCV CD8⁺ T-cell responses, while it could influence immune responses towards unrelated viruses/vaccines (e.g. cytomegalovirus, CMV, and influenza, Flu). The aim of our study was to delineate whether restoration of these virus-specific CD8⁺ T cells occurs after direct-acting antiviral (DAA) therapies and particularly in patients with cirrhosis. We performed longitudinal analysis (baseline, week 4, follow-up [FU] 12 and FU48) of virus-specific CD8⁺ T cells by multicolour flow cytometry in HCV-cirrhotic patients undergoing DAA therapy (n = 26) after in vitro expansion with immunodominant HCV, CMV and Flu epitopes restricted by HLA-A*02. HCV noncirrhotic patients (n = 9) and healthy individuals (n = 10) served as controls. We found that the proliferative capacity of HCV-specific CD8⁺ T cells increased from baseline up to FU48 in a significant proportion of cirrhotic and noncirrhotic patients. Nevertheless, these cells remained poor cytokine producers in both patient groups, regardless of the down-regulation of inhibitory co-regulatory receptors in HCV-cirrhotic patients at FU48. Likewise, high expression levels of these exhaustion markers were detected in CMV-/Flu-specific CD8⁺ T cells in HCV-cirrhotic patients at all time points, albeit without affecting their proliferative capacity or cytokine production. We conclude that DAA therapies induce restoration of the proliferative capacity of HCV-specific CD8⁺ T cells. However, these cells remain phenotypically and functionally impaired. Contrarily, the 'exhausted' phenotype in CMV-/Flu-specific CD8⁺ T cells in HCV-cirrhotic patients did not associate with their functions. Larger studier with longer follow-up may elucidate whether this complex interplay influences the outcome of cirrhotic patients.

Ultrasound Backscatter Envelope Statistics Parametric Imaging for Liver Fibrosis Characterization: A Review

Early detection and diagnosis of liver fibrosis is of critical importance. Currently the gold standard for diagnosing liver fibrosis is biopsy. However, liver biopsy is invasive and associated with sampling errors and can lead to complications such as bleeding. Therefore, developing noninvasive imaging techniques for assessing liver fibrosis is of clinical value. Ultrasound has become the first-line tool for the management of chronic liver diseases. However, the commonly used B-mode ultrasound is qualitative and can cause interobserver or intraobserver difference. Ultrasound backscatter envelope statistics parametric imaging is an important group of quantitative ultrasound techniques that have been applied to characterizing different kinds of tissue. However, a state-of-the-art review of ultrasound backscatter envelope statistics parametric imaging for liver fibrosis characterization has not been conducted. In this paper, we focused on the development of ultrasound backscatter envelope statistics parametric imaging techniques for assessing liver fibrosis from 1998 to September 2019. We classified these techniques into six categories: constant false alarm rate, fiber structure extraction technique, acoustic structure quantification, quantile-quantile probability plot, the multi-Rayleigh model, and the Nakagami model. We presented the theoretical background and algorithms for liver fibrosis assessment by ultrasound backscatter envelope statistics parametric imaging. Then, the specific applications of ultrasound backscatter envelope statistics parametric imaging techniques to liver fibrosis evaluation were reviewed and analyzed. Finally, the pros and cons of each technique were discussed, and the future development was suggested.

Cirrhosis Hampers Early and Rapid Normalization of Natural Killer Cell Phenotype and Function in Hepatitis C Patients Undergoing Interferon-Free Therapy

Background: Chronic hepatitis C virus (HCV) infection impairs natural killer (NK) cell phenotype and function. Whether restoration of NK cells occurs after successful interferon (IFN)-free therapies remains a controversial issue. Aim: To analyze how HCV-related liver cirrhosis impacts changes in NK cells prior and post-IFN-free therapies. Methods: NK cell analysis by multicolor flow cytometry was performed in HCV-infected patients with (n = 17) and without (n = 14) cirrhosis at baseline, week 4 during therapy, and weeks 12 and 48 after the end of therapy (FU12 and FU48, respectively). Non-HCV cirrhotic patients (n = 12) and healthy individuals (n = 12) served as controls. Results: At baseline, HCV cirrhotic patients presented an altered distribution of NK subsets (CD56dim and CD56bright) with higher expression of NKp46, HLA-DR, NKp30, KIR2DL2/L3, NKG2A, and CD85j receptors compared to healthy controls. All frequencies normalized by FU48, except for CD85j+ cells. Likewise, substantial alterations were detected in NK cell function assessed by (i) signal transducer and activator of transcription 1 (STAT1) and phosphorylated levels of STAT1 and STAT4, (ii) degranulation (CD107a), (iii) cytotoxicity [tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)], and (iv) cytokine production [IFN-γ and tumor necrosis factor-α (TNF-α)]. Of note, NK cell function at FU48 remained partially impaired. In contrast, non-cirrhotics showed normal baseline frequencies of HLA-DR-, NKG2A-, and CD85j-expressing NK cells. Importantly, altered baseline frequencies of NK cell subsets and NKp46+ CD56dim cells, as well as NK cell function, were rapidly and completely restored. Conclusions: NK cell phenotype alterations persist after HCV eradication in cirrhotic patients, while their function is only partially restored, compromising immune restoration and immunosurveillance.

Doppler ultrasonography: A non-invasive method used to diagnose and follow up patients with chronic hepatitis C

BACKGROUND AND AIM

This study aimed to investigate the association between the findings of Doppler ultrasonography and transient elastography using FibroScan and to determine the cut-off points, sensitivity, and specificity of resistance indices, and pulsatility of the hepatic vessels to predict significant hepatic fibrosis.

METHODS

This is a transversal, observational, and analytical study that includes 30 patients with chronic hepatitis C who were admitted at a public referral hospital. Transient elastography and ultrasonographic data were collected, and the linear association between these methods was evaluated using the Pearson test. Various Doppler velocimetric indices were compared according to the presence/absence of significant (≥ F2) fibrosis.

RESULTS

There was a moderate-strong linear association between the FibroScan data and the Doppler velocimetric indices and splenic index in the hepatic vessels; the mean values of the indices differed between groups with absent/mild (F0/F1) and significant (≥ F2) hepatic fibrosis. There was an association between the monophasic and biphasic wave pattern of the suprahepatic veins and the stratification of hepatic fibrosis estimated by the values of kilopascal in FibroScan.

CONCLUSION

Doppler ultrasonography is a non-invasive method used to evaluate liver fibrosis, and it presents acceptable sensitivity/specificity for the prediction of fibrosis ≥ F2 in patients with chronic hepatitis C.

Semi-Quantitative Ultrasonographic Evaluation of NAFLD

Nonalcoholic fatty liver disease (NAFLD) embraces histopathological entities ranging from the relatively benign simple steatosis to the progressive form nonalcoholic steatohepatitis (NASH), which is associated with fibrosis and an increased risk of progression to cirrhosis and hepatocellular carcinoma. NAFLD is the most common liver disease and is associated with extrahepatic comorbidities including a major cardiovascular disease burden. The non-invasive diagnosis of NAFLD and the identification of subjects at risk of progressive liver disease and cardio-metabolic complications are key in implementing personalized treatment schedules and follow-up strategies. In this review, we highlight the potential role of ultrasound semiquantitative scores for detecting and assessing steatosis severity, progression of NAFLD, and cardio-metabolic risk. Ultrasonographic scores of fatty liver severity act as sensors of cardio-metabolic health and may assist in selecting patients to submit to second-line non-invasive imaging techniques and/or liver biopsy.

Fibroscan Reliably Rules Out Advanced Liver Fibrosis and Significant Portal Hypertension in Alcoholic Patients

BACKGROUND/GOALS

To date, there is no consensus on optimal cut-off values and timing of transient elastography (TE, Fibroscan) for fibrosis staging and prediction of portal hypertension in alcoholic liver disease. We evaluated the accuracy of Fibroscan for the diagnosis of fibrosis and clinically significant portal hypertension in alcoholic patients.

STUDY

Heavy drinkers admitted to our standardized alcohol withdrawal program were evaluated by Fibroscan, by transjugular hepatic venous pressure gradient (HVPG) measurement and liver biopsy if significant fibrosis was suspected and by upper gastrointestinal endoscopy. All investigations were performed within 3 days of admission. Patients who had remained abstinent for 2 weeks underwent a second Fibroscan.

RESULTS

A total of 118 patients were included. Fibroscan correlated well with histology and HVPG. Negative predictive value of 92% and 93% for ruling out severe fibrosis (≥F3) and cirrhosis, and optimal cut-offs at ≥11.7, ≥15.2, and ≥21.2 kPa for F2, F3, and F4, respectively, were found. In abstinent patients, a mean decrease of 2.7 kPa improved concordance between Fibroscan and histology. A TE value of 30.6 kPa predicted a HVPG>10 mm Hg with 94% specificity and showed a good negative predictive value of 84% for ruling out the presence of varices at endoscopy. Steatosis, alcoholic hepatitis, sinusoidal fibrosis, cholestasis, and high transaminases did not influence TE values.

CONCLUSIONS

Fibroscan is an accurate non-invasive method for the diagnosis of fibrosis in alcoholic patients. TE values below 11 and 30 kPa likely rule out significant fibrosis and varices, respectively.

Simplified follow-up of patients with mild chronic hepatitis C in areas with limited access to antiviral therapy

BACKGROUND AND AIMS

In some areas of the world, antiviral therapy for chronic hepatitis C (CHC) is not available for all patients. The optimal interval for liver stiffness measures (LSM) and noninvasive scores to assess fibrosis progression has not been studied. We evaluated the usefulness of consecutive LSM, APRI, FIB-4 and Forns scores to predict disease progression.

METHODS

Patients with CHC and at least two annual LSM within 3 years were followed for a minimum of 5 years. Noninvasive scores were assessed. Evolution of LSM and scores were expressed as change/year (Delta).

RESULTS

623 non-cirrhotic patients were included. Median baseline LSM was 6.6 kPa (IQR 5.4-8.4). During a median follow-up of 6 years, 61(9.7%) patients developed cirrhosis. Baseline LSM ≥ F2 and Forns ≥ 6.9 were the main predictors of cirrhosis (C-index 0.97). The addition of Delta variables did not improve its prediction. In patients with mild fibrosis (F0-1), progression to ≥F2 occurred in 80 (23%) within the first 3 years. Baseline BMI ≥ 24 kg/m² and LSM ≥ 5.9 kPa were associated to progression.

CONCLUSIONS

Baseline LSM and Forns are highly predictive of cirrhosis development. In patients with mild CHC, BMI < 24 and LSM < 5.9, the likelihood of progression is very low, allowing for a significant spacing of noninvasive assessments over time.

The effect of vitamin D pathway genes and deferasirox pharmacogenetics on liver iron in thalassaemia major patients

Monitoring and treating iron overload is crucial in transfusion-dependent thalassaemia patients. Liver stiffness measurement by transient elastography and T2* magnetic resonance imaging represent non-invasive ways to evaluate the adequacy of the iron chelation treatment. We explored the role of single nucleotide polymorphisms involved in vitamin D metabolism, transport and activity, and in deferasirox metabolism on liver iron burden parameters. One-hundred and five beta-thalassaemia patients, treated with deferasirox, have been enrolled. Drug plasma C_trough and AUC were measured by a HPLC-UV method. Allelic discrimination was performed by real-time PCR. Age, UGT1A1-364 CT/TT and CYP27B1 -1260 GT/TT positively predicted liver stiffness values. Deferasirox dose and serum ferritin negatively predicted T2* data, whereas age and CYP2D6 1457 GG genotype positively influenced these values. The discoveries of this research may be useful for personalized medicine and the proposed method could be applied in patients with hereditary hemochromatosis and myelodysplastic syndromes.

Evaluation of texture features at staging liver fibrosis based on phase contrast X-ray imaging

BACKGROUND

The purpose of this study is to explore the potential of phase contrast imaging to detect fibrotic progress in its early stage; to investigate the feasibility of texture features for quantified diagnosis of liver fibrosis; and to evaluate the performance of back propagation (BP) neural net classifier for characterization and classification of liver fibrosis.

METHODS

Fibrous mouse liver samples were imaged by X-ray phase contrast imaging, nine texture measures based on gray-level co-occurrence matrix were calculated and the feasibility of texture features in the characterization and discrimination of liver fibrosis at early stages was investigated. Furthermore, 36 or 18 features were applied to the input of BP classifier; the classification performance was evaluated using receiver operating characteristic curve.

RESULTS

The phase contrast images displayed a vary degree of texture pattern from normal to severe fibrosis stages. The BP classifier could distinguish liver fibrosis among normal, mild, moderate and severe stages; the average accuracy was 95.1% for 36 features, and 91.1% for 18 features.

CONCLUSION

The study shows that early stages of liver fibrosis can be discriminated by the morphological features on the phase contrast images. BP network model based on combination of texture features is demonstrated effective for staging liver fibrosis.

Hepatitis C virus early kinetics and resistance-associated substitution dynamics during antiviral therapy with direct-acting antivirals

The emergence of resistance-associated substitutions (RASs) can compromise the high efficacy of direct-acting antivirals (DAAs). Little is known about RASs selection at very early time points during DAA treatment. Therefore, we analyzed the potential emergence of RASs immediately after therapy initiation. Samples of 71 patients treated with different DAAs were collected at baseline, during therapy (hours 4 and 8; days 1-7; weeks 2-4) or until target not detected. HCV-RNA levels were determined by qPCR, and RASs were detected by deep sequencing. Sixty-three (89%) patients achieved a sustained virological response (SVR), 7 (10%) relapsed, and 1 (1%) experienced a breakthrough. Almost all non-SVR (7/8, 88%) showed RASs either at baseline or relapse. High-frequency RASs detected at baseline (Y93H and L159F+C316N) remained detectable at early time points during therapy and reappeared as most prevalent substitutions at relapse. Conversely, emergent RASs at relapse (Q80R, D168E/V, R155K and L31V) were not observed during the first hours-days, before HCV-RNA became undetectable. HCV-RNA decay and genetic evolution of the quasispecies followed a similar pattern during the first hours of therapy in SVR and non-SVR patients. In conclusion, the absence of early RASs selection and the similar dynamics of HCV kinetics and quasispecies in SVR and non-SVR patients after therapy initiation suggest that RASs selection may occur at later stages in the remaining reservoir, where viral populations persist hidden at very low replication levels. Nevertheless, we cannot completely exclude very early selection, when RASs are present below the sensitivity limit of deep sequencing.

The severity of NAFLD is associated with the risk of urolithiasis

BACKGROUND AND AIMS

Population-based studies suggest a strong association between the presence of nonalcoholic fatty liver disease (NAFLD) and an increased risk of urolithiasis. However, the available information on the association of the severity of NAFLD with urolithiasis is limited. We hypothesised a link between the severity of NAFLD and the risk of urolithiasis.

METHODS

We recruited 1527 adult patients with NAFLD who completed a comprehensive health checkup. The severity of NAFLD was measured with AST to platelet ratio (APRI score). Logistic regression analysis was used to detect the association of APRI score with the risk of urolithiasis among NAFLD patients. ROC analysis was used to assess the diagnostic value of APRI score for identifying urolithiasis among NAFLD patients.

RESULTS

Multivariate analysis showed three independent risk factors for urolithiasis: obesity (OR 2.06 95%CI 1.35-3.13), APRI score (OR 1.29 95%CI 1.05-1.59), and serum uric acid (OR 1.07 95%CI 1.05-1.09), suggesting an independent association between the noninvasive staging of liver fibrosis and the risk of urolithiasis in NAFLD patients. A three-variable model (obesity, APRI score, and serum uric acid) with an AUROC of 0.73 (95% CI 0.70-0.75) was significant in identifying urolithiasis.

CONCLUSIONS

The severity of NAFLD is associated with the risk of urolithiasis among NAFLD patients. Moreover, a three-variable model (obesity, APRI score, serum uric acid) could serve as a useful tool for identifying individuals at high risk for urolithiasis in these patients.

Multiparametric ultrasomics of significant liver fibrosis: A machine learning-based analysis

Objective

To assess significant liver fibrosis by multiparametric ultrasomics data using machine learning.

Materials and Methods

This prospective study consisted of 144 patients with chronic hepatitis B. Ultrasomics—high-throughput quantitative data from ultrasound imaging of liver fibrosis—were generated using conventional radiomics, original radiofrequency (ORF) and contrast-enhanced micro-flow (CEMF) features. Three categories of features were explored using pairwise correlation and hierarchical clustering. Features were selected using diagnostic tests for fibrosis, activity and steatosis stage, with the histopathological results as the reference. The fibrosis staging performance of ultrasomics models with combinations of the selected features was evaluated with machine-learning algorithms by calculating the area under the receiver-operator characteristic curve (AUC).

Results

ORF and CEMF features had better predictive power than conventional radiomics for liver fibrosis stage (both p < 0.01). CEMF features exhibited the highest diagnostic value for activity stage (both p < 0.05), and ORF had the best diagnostic value for steatosis stage (both p < 0.01). The machine-learning classifiers of adaptive boosting, random forest and support vector machine were found to be optimal algorithms with better (all mean AUCs = 0.85) and more stable performance (coefficient of variation = 0.01–0.02) for fibrosis staging than decision tree, logistic regression and neural network (mean AUC = 0.61–0.72, CV = 0.07–0.08). The multiparametric ultrasomics model achieved much better performance (mean AUC values of 0.78–0.85) than the features from a single modality in discriminating significant fibrosis (≥ F2).

Conclusion

Machine-learning-based analysis of multiparametric ultrasomics can help improve the discrimination of significant fibrosis compared with mono or dual modalities.

Key Points

• Multiparametric ultrasomics has achieved much better performance in the discrimination of significant fibrosis (≥ F2) than the single modality of conventional radiomics, original radiofrequency and contrast-enhanced micro-flow.

• Adaptive boosting, random forest and support vector machine are the optimal algorithms for machine learning.

Electronic supplementary material

The online version of this article (10.1007/s00330-018-5680-z) contains supplementary material, which is available to authorized users.

Long-Term Outcomes of Patients With HCV-Associated Cryoglobulinemic Vasculitis After Virologic Cure

Patients with hepatitis C virus-associated cryoglobulinemic vasculitis (HCV-CV) have high rates of clinical remission after treatment with direct-acting antivirals (DAAs), but circulating cryoglobulins persist, and vascular disorders reappear in some patients shortly after DAA treatment ends. We performed a prospective study to assess the long-term clinical and immune system effects of HCV eradication with DAAs in 46 patients with HCV-CV and 42 asymptomatic patients with circulating cryoglobulins. A median of 24 months after DAA treatment (range, 17-41 months), 66% of patients with HCV-CV and 70% of asymptomatic patients with circulating cryoglobulins had an immunologic response, with comparable reductions in cryocrit from 2.6% to 0% (P < .05). However, 20% of patients still had positive test results for cryoglobulins after DAA therapy. Among patients with HCV-CV, 42 (91%) had a clinical response, in that their Birmingham Vasculitis Activity Score (version 3) decreased from 7 to 0 (P < .01). Nevertheless, within 2 years after a sustained viral response to DAA therapy, 5 patients with HCV-CV (11%, 4 with cirrhosis) had relapses of vasculitis that included severe organ damage and death.

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

Purpose

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

Methods

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

Results

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

Conclusion

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

Hepatic Steatosis Assessment with Ultrasound Small-Window Entropy Imaging

Nonalcoholic fatty liver disease is a type of hepatic steatosis that is not only associated with critical metabolic risk factors but can also result in advanced liver diseases. Ultrasound parametric imaging, which is based on statistical models, assesses fatty liver changes, using quantitative visualization of hepatic-steatosis-caused variations in the statistical properties of backscattered signals. One constraint with using statistical models in ultrasound imaging is that ultrasound data must conform to the distribution employed. Small-window entropy imaging was recently proposed as a non-model-based parametric imaging technique with physical meanings of backscattered statistics. In this study, we explored the feasibility of using small-window entropy imaging in the assessment of fatty liver disease and evaluated its performance through comparisons with parametric imaging based on the Nakagami distribution model (currently the most frequently used statistical model). Liver donors (n = 53) and patients (n = 142) were recruited to evaluate hepatic fat fractions (HFFs), using magnetic resonance spectroscopy and to evaluate the stages of fatty liver disease (normal, mild, moderate and severe), using liver biopsy with histopathology. Livers were scanned using a 3-MHz ultrasound to construct B-mode, small-window entropy and Nakagami images to correlate with HFF analyses and fatty liver stages. The diagnostic values of the imaging methods were evaluated using receiver operating characteristic curves. The results demonstrated that the entropy value obtained using small-window entropy imaging correlated well with log10(HFF), with a correlation coefficient r = 0.74, which was higher than those obtained for the B-scan and Nakagami images. Moreover, small-window entropy imaging also resulted in the highest area under the receiver operating characteristic curve (0.80 for stages equal to or more severe than mild; 0.90 for equal to or more severe than moderate; 0.89 for severe), which indicated that non-model-based entropy imaging-using the small-window technique-performs more favorably than other techniques in fatty liver assessment.

Utility of shear-wave elastography to differentiate low from advanced degrees of liver fibrosis in patients with hepatitis C virus infection of native and transplant livers

OBJECTIVE

To determine the accuracy of shear-wave elastography (SWE) to differentiate low from advanced degrees of liver fibrosis in hepatitis C patients.

MATERIAL & METHOD

Consented native/transplant hepatitis C patients underwent SWE using a C1-6 MHz transducer before ultrasound (US)-guided liver biopsy. Five interpretable SWE samples were obtained from the right lobe of the liver immediately before US-guided random biopsy of the right lobe. Average kilopascal (kPa) values were compared to the meta-analysis of histological data in viral hepatitis (METAVIR) fibrosis grading. SWE values were correlated with the degree of inflammation and fatty infiltration.

RESULTS

Study population consisted of 115 patients (63 with transplant, and 52 with native liver) including 29 women and 86 men, with a mean ± SD age of 56 ± 8.7 years. Mean ± SD SWE values were 7.9 ± 3 kPa in 83 patients with METAVIR scores of 0-2 and 13.2 ± 5.9 kPa in 32 patients with METAVIR scores of 3 or 4 (P < .001). Area under curve (AUC) of a Receiver Operating Characteristics curve for advanced degrees of fibrosis was 0.81 (95% CI: 0.71, 0.90) (P < .001). AUCs of transplant versus native livers (0.78 [CI:0.62, 0.94] versus 0.85 [CI: 0.73, 0.96]), degree of inflammation (0.81 [CI: 0.65, 0.97] versus 0.72 [0.56, 0.88]), or degree of fat deposition (0.81 [CI:0.70, 0.92] versus 0.80 [CI:0.61, 1]) were not statistically different (P > .05). for kPa threshold of SWE value of 10.67 kPa to differentiate advanced from low degree of fibrosis had a sensitivity of 59% (CI: 41%-76%) and specificity of 90% (CI: 82%-96%).

CONCLUSION

Liver stiffness evaluated by SWE can differentiate low from advanced liver fibrosis.

Anti-viral therapy can be delayed or avoided in a significant proportion of HBeAg-negative Caucasian patients in the Grey Zone

BACKGROUND

Grey Zone (GZ) is an ill-defined situation including patients falling between inactive carrier (IC) state and HBeAg-negative chronic hepatitis B (HBeAg-negative CHB).

AIMS

To assess the long-term outcomes of GZ patients compared to IC in the absence of treatment.

METHODS

Retrospective analysis of 287 IC and GZ HBeAg-negative patients. Patients were classified into 4 groups at baseline: HBV-DNA <2000 IU/mL and ALT <40 U/L (IC), HBV-DNA <2000 IU/mL and ALT 40-80 U/L (GZ-1), HBV-DNA 2000-20 000 IU/mL and ALT <40 U/L (GZ-2) or ALT 40-80 U/L (GZ-3). Data were also analysed using AASLD ALT criteria.

RESULTS

After a median follow-up of 8.2 (5-19) years, HBsAg loss occurred in about 15% ICs or GZ patients. Transition into IC state occurred in 40% of GZ patients. DNA fluctuations >2000 IU/mL correlated inversely with transition into IC and HBsAg loss. HBsAg levels were significantly lower in ICs than in GZ patients (338 IU/mL [20-3269] vs 5763 IU/mL [2172-17 754]; P < 0.05). Among the latter group, there was an increasing gradient of HBsAg levels from GZ-1 to GZ-3 patients (P < 0.05). HBeAg-negative CHB occurred in only 18 (6.3%) GZ patients. No patient developed cirrhosis nor advanced fibrosis. ALT/HBV-DNA fluctuations and HBeAg-negative CHB development were more frequent in genotype B/C patients, whereas HBsAg loss occurred only in genotype A/D patients.

CONCLUSIONS

Most Caucasian GZ patients present excellent long-term outcomes in the absence of treatment, with a high rate of HBsAg loss and low rate of progression to HBeAg-negative CHB. HBV-genotyping and HBsAg levels could help to predict outcomes and better classify GZ patients.

Usefulness of virtual touch quantification for staging liver fibrosis in patients with hepatitis C, and factors affecting liver stiffness measurement failure compared with liver biopsy

AIM

The assessment of liver fibrosis in patients with hepatitis C is important to predict carcinogenesis. In this study, we evaluated the usefulness of virtual touch quantification (VTQ) for staging liver fibrosis, and investigated factors causing discrepancies between the estimated fibrosis stage using VTQ and the pathological fibrosis stage.

METHODS

Patients with hepatitis C (n = 302) were assessed using VTQ and underwent pathological liver investigation within 1 week before and after VTQ. A receiver operator characteristic (ROC) curve was obtained for VTQ, fibrosis-4 (FIB-4) index, and aspartate aminotransferase-to-platelet ratio index (APRI), and each area under the ROC curve (AUROC) was compared to predict fibrosis stage. We used univariate and multivariate analyses to investigate the factors related to the discrepancy between the estimated fibrosis stage using VTQ and the pathological fibrosis stage.

RESULTS

At any stage, VTQ was the most accurate for staging liver fibrosis. The VTQ cut-off values were 1.33 m/s (AUROC = 0.822) for ≥F2, 1.51 m/s (AUROC = 0.836) for ≥F3, and 1.92 m/s (AUROC = 0.890) for F4. Skin liver capsule distance (SCD) was the most relevant factor for the discrepancy between the estimated fibrosis stage using VTQ and the pathological fibrosis stage. The SCD cut-off value was 17.5 mm.

CONCLUSIONS

Virtual touch quantification is a non-invasive, simple method that is more accurate for staging liver fibrosis than the FIB-4 index and APRI. However, when the SCD is longer than 17.5 mm, there may be measurement failures.

Effect of oral antiviral treatment on long-term outcomes of radiofrequency ablation therapy for hepatitis B virus-related hepatocellular carcinoma

OBJECTIVES

This study aimed to investigate the effect of oral antiviral treatment on the prognosis of hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) after radiofrequency (RF) ablation.

METHODS

Between January 2003 and December 2010, 228 patients without a history of antiviral treatment were treated with RF ablation for a single HBV-related HCC. We divided the patients into two groups, patients who received (n=125) or did not receive antiviral treatment (n=103), based on whether oral antiviral treatment was administered after RF ablation. The median duration of antiviral treatment was 60.1 months. HCC recurrence and overall survival were compared in the two groups in the full cohort and the propensity score-matched cohort.

RESULTS

In the matched cohort, the probability of HCC recurrence at 5 years was 43.8% for the non-antiviral treatment group and 14.7% for the antiviral treatment group (p<0.001). The probability of overall survival at 5 years was 77.2% for the non-antiviral treatment group and 93.5% for the antiviral treatment group (p=0.002). Multivariable analysis showed that risk factors for HCC recurrence included large tumor size (hazard ratio (HR)=1.30, p=0.022), HBV DNA serum level (HR=1.11, p=0.005), and serum AFP level ≥20 ng/mL (HR=1.66, p=0.005). Overall survival was associated with larger tumor size (HR=1.86, p=0.001) and Child-Pugh Class B (HR=2.13, p=0.019). Oral antiviral treatment after RF ablation was significantly associated with a lower risk of tumor recurrence and death (HR=0.33, p<0.001, and HR=0.44, p=0.004).

CONCLUSION

Use of oral antiviral treatment after curative RF ablation was associated with favorable outcomes in terms of tumor recurrence and overall survival in patients with HBV-related HCC.

Effect of ultrasound frequency on the Nakagami statistics of human liver tissues

The analysis of the backscattered statistics using the Nakagami parameter is an emerging ultrasound technique for assessing hepatic steatosis and fibrosis. Previous studies indicated that the echo amplitude distribution of a normal liver follows the Rayleigh distribution (the Nakagami parameter m is close to 1). However, using different frequencies may change the backscattered statistics of normal livers. This study explored the frequency dependence of the backscattered statistics in human livers and then discussed the sources of ultrasound scattering in the liver. A total of 30 healthy participants were enrolled to undergo a standard care ultrasound examination on the liver, which is a natural model containing diffuse and coherent scatterers. The liver of each volunteer was scanned from the right intercostal view to obtain image raw data at different central frequencies ranging from 2 to 3.5 MHz. Phantoms with diffuse scatterers only were also made to perform ultrasound scanning using the same protocol for comparisons with clinical data. The Nakagami parameter-frequency correlation was evaluated using Pearson correlation analysis. The median and interquartile range of the Nakagami parameter obtained from livers was 1.00 (0.98-1.05) for 2 MHz, 0.93 (0.89-0.98) for 2.3 MHz, 0.87 (0.84-0.92) for 2.5 MHz, 0.82 (0.77-0.88) for 3.3 MHz, and 0.81 (0.76-0.88) for 3.5 MHz. The Nakagami parameter decreased with the increasing central frequency (r = -0.67, p < 0.0001). However, the effect of ultrasound frequency on the statistical distribution of the backscattered envelopes was not found in the phantom results (r = -0.147, p = 0.0727). The current results demonstrated that the backscattered statistics of normal livers is frequency-dependent. Moreover, the coherent scatterers may be the primary factor to dominate the frequency dependence of the backscattered statistics in a liver.

Acoustic Radiation Force Impulse Imaging for Assessing Liver Fibrosis Preoperatively in Infants With Biliary Atresia: Comparison With Liver Fibrosis Biopsy Pathology

OBJECTIVES

The purpose of this study was to investigate the diagnostic performance of acoustic radiation force impulse (ARFI) in assessing liver fibrosis preoperatively in infants with biliary atresia (BA).

METHODS

A total of 50 consecutive infants with BA and 50 healthy infants who underwent ARFI examination were recruited. Siemens Acuson S2000 in Virtual Touch Quantification mode (Siemens Medical Solutions, Mountain View, CA) was used to measure shear wave speeds (SWSs). All infants with BA underwent a liver biopsy within 3 days after ARFI imaging. The liver fibrosis stages of specimens were defined according to the Batts-Ludwig scoring system. The correlation analysis was performed between SWSs and pathological findings. Cut-off values were determined using receiver operating characteristic (ROC) curves.

RESULTS

The mean SWS in the BA group was significantly higher than controls (mean ± standard deviation): 1.89 ± 0.45 versus 1.12 ± 0.06 m/s; P < .001). A significant correlation was found between the SWSs and fibrosis stages (r = 0.719, P < .001). The cut-off value for predicting significant fibrosis (F ≥ 2), severe fibrosis (F ≥ 3), and cirrhosis (F = 4) was 1.53, 1.80 and 2.16 m/s, respectively, and the area under the ROC curve was 0.823, 0.884 and 0.917, respectively.

CONCLUSIONS

Acoustic radiation force impulse imaging showed significant correlation with the severity of liver fibrosis by comparing it with liver fibrosis biopsy pathology. It may be an effective method for liver fibrosis assessment, prognosis prediction, and clinical management in infants with BA.

Point Shear Wave Elastography in Assessment of Hepatic Fibrosis: Diagnostic Accuracy in Subjects With Native and Transplanted Livers Referred for Percutaneous Biopsy

The objective of this study was to prospectively evaluate the use of point shear wave elastography for the assessment of liver fibrosis and to determine the usefulness and optimal location for obtaining elastography measurements in native and transplanted livers. Point shear wave elastography measurements were obtained from 100 consecutive patients presenting for percutaneous liver biopsy. Measurements were acquired within both the superior right hepatic lobe (segments VII/VIII) via an intercostal approach and the inferior right hepatic lobe (segments V/VI) via a subcostal approach. Analysis of variance was used to assess statistical differences between the degree of fibrosis on percutaneous liver biopsy and elastography measurements. No statistical difference was present when comparing elastography measurements in patients with hepatic steatosis compared with patients without steatosis (P = 0.2759). There was no difference in the accuracy of elastography measurements in native livers versus transplanted livers (P = 0.221). Point shear wave elastography can accurately differentiate between patients with no-to-mild hepatic fibrosis (F0-F1) and moderate-to-severe hepatic fibrosis (≥F2) with sensitivity of 72% and specificity of 69%. Point shear wave elastography can be used as a noninvasive method to assess fibrosis in patients with native or transplanted livers. In addition, measurements can be combined or taken separately from either the superior or inferior right hepatic lobe. The presence of hepatic steatosis does not affect the accuracy of point shear wave elastography. However, shear wave elastography values in patients with body mass index greater than 40 should be interpreted with caution.

Virologic, Clinical, and Immune Response Outcomes of Patients With Hepatitis C Virus-Associated Cryoglobulinemia Treated With Direct-Acting Antivirals

BACKGROUND & AIMS

Cryoglobulins (circulating immune complexes of polyclonal IgG, monoclonal IgM, and rheumatoid factor) are detected in the circulation of 40% to 60% of patients with chronic hepatitis C virus infection, and cryoglobulinemic vasculitis (CV) is observed in approximately 10% of patients. We aimed to assess the clinical and immune effects of direct-acting antiviral treatment.

METHODS

We performed a prospective study of 64 patients with HCV infection with circulating cryoglobulins receiving direct-acting antiviral therapy at a single center in Barcelona, Spain, from January 2014 through April 2016. Patients were classified as having CV (n = 35) or asymptomatic circulating cryoglobulins (ACC, n = 29). Clinical response was considered complete if a patient's Birmingham Vasculitis Activity Score (version 3) was 0, or if all affected organs improved 12 weeks after the end of therapy. A complete immunologic response (CIR) was defined as no detection of circulating cryoglobulins and normalized levels of complement and/or rheumatoid factor.

RESULTS

Clinical manifestations of CV included purpura (65%), weakness (70%), arthralgia (31%), myalgia (20%), peripheral neuropathy (50%), and renal involvement (20%). At baseline, patients with CV had significantly higher levels of rheumatoid factor and lower levels of C4 complement than patients with ACC, whereas cryocrits were similar between groups (3.2% vs 2.6%). Overall, 60 patients (94%) had a sustained viral response 12 weeks after therapy. Among patients with CV, the median Birmingham Vasculitis Activity Score (version 3) decreased from 9 (range, 2-31) to 3 (range, 0-12) (P < .001). Twenty-five patients with CV (71%) achieved a complete clinical response. Immune-suppressive therapy was reduced for 4 of 13 patients and withdrawn for 6 of 13. Overall, 48% of patients achieved a CIR. A low baseline cryocrit level (<2.7%) was the only factor associated with CIR (odds ratio, 9.8; 95% confidence interval, 2.2-44; P = .03).

CONCLUSIONS

Viral eradication was associated with clinical improvement in most patients with CV. Markers of immune activation, including circulating cryoglobulins, persisted in 52% of patients with CV or ACC, despite a sustained viral response 12 weeks after therapy. A longer follow-up period after viral eradication might be necessary to ensure a normal immune response.

Computer-aided Characterization and Diagnosis of Diffuse Liver Diseases Based on Ultrasound Imaging: A Review

Diffuse liver diseases, such as hepatitis, fatty liver, and cirrhosis, are becoming a leading cause of fatality and disability all over the world. Early detection and diagnosis of these diseases is extremely important to save lives and improve effectiveness of treatment. Ultrasound imaging, a noninvasive diagnostic technique, is the most commonly used modality for examining liver abnormalities. However, the accuracy of ultrasound-based diagnosis depends highly on expertise of radiologists. Computer-aided diagnosis systems based on ultrasound imaging assist in fast diagnosis, provide a reliable "second opinion" for experts, and act as an effective tool to measure response of treatment on patients undergoing clinical trials. In this review, we first describe appearance of liver abnormalities in ultrasound images and state the practical issues encountered in characterization of diffuse liver diseases that can be addressed by software algorithms. We then discuss computer-aided diagnosis in general with features and classifiers relevant to diffuse liver diseases. In later sections of this paper, we review the published studies and describe the key findings of those studies. A concise tabular summary comparing image database, features extraction, feature selection, and classification algorithms presented in the published studies is also exhibited. Finally, we conclude with a summary of key findings and directions for further improvements in the areas of accuracy and objectiveness of computer-aided diagnosis.

Echocardiography as a Screening Test for Myocardial Scarring in Children with Hypertrophic Cardiomyopathy

Introduction. Hypertrophic cardiomyopathy (HCM) is burdened with morbidity and mortality including tachyarrhythmias and sudden cardiac death. These complications are attributed in part to the formation of proarrhythmic scars in the myocardium. The presence of extensive LGE is a risk factor for adverse outcomes in HCM. Late gadolinium enhancement (LGE) cardiac magnetic resonance imaging (cMRI) is the standard for the noninvasive evaluation of myocardial scars. However, echocardiography represents an attractive screening tool for myocardial scarring. The aim of this study was to compare the suitability of echocardiography to detect myocardial scars to the standard of cMRI-LGE. Methods. The cMRI studies and echocardiograms from 56 consecutive children with HCM were independently evaluated for the presence of cMRI-LGE and echocardiographic evidence of scarring by expert readers. Results. Echocardiography had a high sensitivity (93%) and negative predictive value (94%) in comparison to LGE. The false positive rate was high, leading to a low specificity (37%) and a low positive predictive value (35%). Conclusions. Given the poor specificity and positive predictive value, echocardiography is not a suitable screening test for the presence of myocardial scarring in children with HCM. However, children without echocardiographic evidence of myocardial scarring may not need to undergo cardiac magnetic resonance imaging to “rule in” LGE.

Elastography of shear wave speed imaging for the evaluation of liver fibrosis: A meta-analysis

AIM

A meta-analysis was carried out to assess the accuracies of shear wave speed imaging (SWSI) in predicting significant fibrosis (stages F2-4) and cirrhosis (stage F4).

METHODS

A review was performed of relevant studies published until October 2015. A bivariate binomial model was used to combine the sensitivity, specificity, and the area under the summary receiver operating characteristic (AUC), and 95% confidence intervals were derived to indicate the diagnostic accuracy of imaging modalities.

RESULTS

In total, 10 studies with 2182 patients were included in the analysis. The sensitivity, specificity, and AUC (with 95% confidence intervals) of SWSI were: 0.84 (0.81-0.87), 0.83 (0.77-0.88), and 0.88 (0.85-0.90) for significant fibrosis, respectively; and 0.80 (0.66-0.89), 0.93 (0.88-0.96), and 0.95 (0.92-0.96) for cirrhosis, respectively. When SWSI was compared with well-evaluated transient elastography, the AUCs for the prediction of significant fibrosis were 0.93 and 0.86, respectively. The AUCs for the prediction of cirrhosis were both 0.94.

CONCLUSION

Shear wave speed imaging is a trustworthy tool for staging hepatic fibrosis, with a high combination of sensitivity and specificity. Compared with transient elastography, SWSI showed better diagnostic performance for the prediction of significant fibrosis.

Acoustic structure quantification by using ultrasound Nakagami imaging for assessing liver fibrosis

Acoustic structure quantification (ASQ) is a recently developed technique widely used for detecting liver fibrosis. Ultrasound Nakagami parametric imaging based on the Nakagami distribution has been widely used to model echo amplitude distribution for tissue characterization. We explored the feasibility of using ultrasound Nakagami imaging as a model-based ASQ technique for assessing liver fibrosis. Standard ultrasound examinations were performed on 19 healthy volunteers and 91 patients with chronic hepatitis B and C (n = 110). Liver biopsy and ultrasound Nakagami imaging analysis were conducted to compare the METAVIR score and Nakagami parameter. The diagnostic value of ultrasound Nakagami imaging was evaluated using receiver operating characteristic (ROC) curves. The Nakagami parameter obtained through ultrasound Nakagami imaging decreased with an increase in the METAVIR score (p < 0.0001), representing an increase in the extent of pre-Rayleigh statistics for echo amplitude distribution. The area under the ROC curve (AUROC) was 0.88 for the diagnosis of any degree of fibrosis (≥F1), whereas it was 0.84, 0.69, and 0.67 for ≥F2, ≥F3, and ≥F4, respectively. Ultrasound Nakagami imaging is a model-based ASQ technique that can be beneficial for the clinical diagnosis of early liver fibrosis.

Ultrasound window-modulated compounding Nakagami imaging: Resolution improvement and computational acceleration for liver characterization

Ultrasound Nakagami imaging is an attractive method for visualizing changes in envelope statistics. Window-modulated compounding (WMC) Nakagami imaging was reported to improve image smoothness. The sliding window technique is typically used for constructing ultrasound parametric and Nakagami images. Using a large window overlap ratio may improve the WMC Nakagami image resolution but reduces computational efficiency. Therefore, the objectives of this study include: (i) exploring the effects of the window overlap ratio on the resolution and smoothness of WMC Nakagami images; (ii) proposing a fast algorithm that is based on the convolution operator (FACO) to accelerate WMC Nakagami imaging. Computer simulations and preliminary clinical tests on liver fibrosis samples (n=48) were performed to validate the FACO-based WMC Nakagami imaging. The results demonstrated that the width of the autocorrelation function and the parameter distribution of the WMC Nakagami image reduce with the increase in the window overlap ratio. One-pixel shifting (i.e., sliding the window on the image data in steps of one pixel for parametric imaging) as the maximum overlap ratio significantly improves the WMC Nakagami image quality. Concurrently, the proposed FACO method combined with a computational platform that optimizes the matrix computation can accelerate WMC Nakagami imaging, allowing the detection of liver fibrosis-induced changes in envelope statistics. FACO-accelerated WMC Nakagami imaging is a new-generation Nakagami imaging technique with an improved image quality and fast computation.

Simultaneous SPECT imaging of multi-targets to assist in identifying hepatic lesions

Molecular imaging technique is an attractive tool to detect liver disease at early stage. This study aims to develop a simultaneous dual-isotope single photon emission computed tomography (SPECT)/CT imaging method to assist diagnosis of hepatic tumor and liver fibrosis. Animal models of liver fibrosis and orthotopic human hepatocellular carcinoma (HCC) were established. The tracers of ¹³¹I-NGA and ^99mTc-3P-RGD₂ were selected to target asialoglycoprotein receptor (ASGPR) on the hepatocytes and integrin α_vβ₃ receptor in tumor or fibrotic liver, respectively. SPECT imaging and biodistribution study were carried out to verify the feasibility and superiority. As expected, ^99mTc-3P-RGD₂ had the ability to evaluate liver fibrosis and detect tumor lesions. ¹³¹I-NGA showed that it was effective in assessing the anatomy and function of the liver. In synchronized dual-isotope SPECT/CT imaging, clear fusion images can be got within 30 minutes for diagnosing liver fibrosis and liver cancer. This new developed imaging approach enables the acquisition of different physiological information for diagnosing liver fibrosis, liver cancer and evaluating residual functional liver volume simultaneously. So synchronized dual-isotope SPECT/CT imaging with ^99mTc-3P-RGD₂ and ¹³¹I-NGA is an effective approach to detect liver disease, especially liver fibrosis and liver cancer.

Novel 3D Magnetic Resonance Elastography for the Noninvasive Diagnosis of Advanced Fibrosis in NAFLD: A Prospective Study

OBJECTIVES

Recent studies show two-dimensional (2D)-magnetic resonance elastography (MRE) is accurate in diagnosing advanced fibrosis (stages 3 and 4) in nonalcoholic fatty liver disease (NAFLD) patients. Three-dimensional (3D)-MRE is a more advanced version of the technology that can image shear-wave fields in 3D of the entire liver. The aim of this study was to prospectively compare the diagnostic accuracy of 3D-MRE and 2D-MRE for diagnosing advanced fibrosis in patients with biopsy-proven NAFLD.

METHODS

This cross-sectional analysis of a prospective study included 100 consecutive patients (56% women) with biopsy-proven NAFLD who also underwent MRE. Area under the receiver operating characteristic (AUROC) analysis was performed to assess the accuracy of 2D- and 3D-MRE in diagnosing advanced fibrosis.

RESULTS

The mean (±s.d.) of age and body mass index were 50.2 (±13.6) years and 32.1 (±5.0) kg/m(2), respectively. The AUROC for diagnosing advanced fibrosis was 0.981 for 3D-MRE at 40 Hz, 0.927 for 3D-MRE at 60 Hz (standard shear-wave frequency), and 0.921 for 2D-MRE at 60 Hz (standard shear-wave frequency). At a threshold of 2.43 kPa, 3D-MRE at 40 Hz had sensitivity 1.0, specificity 0.94, positive predictive value 0.72, and negative predictive value 1.0 for diagnosing advanced fibrosis. 3D-MRE at 40 Hz had significantly higher AUROC (P<0.05) than 2D-MRE at 60 Hz for diagnosing advanced fibrosis.

CONCLUSIONS

Utilizing a prospective study design, we demonstrate that 3D MRE at 40 Hz has the highest diagnostic accuracy in diagnosing NAFLD advanced fibrosis. Both 2D- and 3D-MRE at 60 Hz, the standard shear-wave frequency, are also highly accurate in diagnosing NAFLD advanced fibrosis.

Primary biliary cirrhosis degree assessment by acoustic radiation force impulse imaging and hepatic fibrosis indicators

AIM: To evaluate the assessment of primary biliary cirrhosis degree by acoustic radiation force impulse imaging (ARFI) and hepatic fibrosis indicators.

METHODS: One hundred and twenty patients who developed liver cirrhosis secondary to primary biliary cirrhosis were selected as the observation group, with the degree of patient liver cirrhosis graded by Child-Pugh (CP) score. Sixty healthy individuals were selected as the control group. The four indicators of hepatic fibrosis were detected in all research objects, including hyaluronic acid (HA), laminin (LN), type III collagen (PC III), and type IV collagen (IV-C). The liver parenchyma hardness value (LS) was then measured by ARFI technique. LS and the four indicators of liver fibrosis (HA, LN, PC III, and IV-C) were observed in different grade CP scores. The diagnostic value of LS and the four indicators of liver fibrosis in determining liver cirrhosis degree with PBC, whether used alone or in combination, were analyzed by receiver operating characteristic (ROC) curve.

RESULTS: LS and the four indicators of liver fibrosis within the three classes (A, B, and C) of CP scores in the observation group were higher than in the control group, with C class > B class > A class; the differences were statistically significant (P < 0.01). Although AUC values of LS within the three classes of CP scores were higher than in the four indicators of liver fibrosis, sensitivity and specificity were unstable. The ROC curves of LS combined with the four indicators of liver fibrosis revealed that: AUC and sensitivity in all indicators combined in the A class of CP score were higher than in LS alone, albeit with slightly decreased specificity; AUC and specificity in all indicators combined in the B class of CP score were higher than in LS alone, with unchanged sensitivity; AUC values (0.967), sensitivity (97.4%), and specificity (90%) of all indicators combined in the C class of CP score were higher than in LS alone (0.936, 92.1%, 83.3%).

CONCLUSION: The diagnostic value of PBC cirrhosis degree in liver cirrhosis degree assessment by ARFI combined with the four indicators of serum liver fibrosis is of satisfactory effectiveness and has important clinical application value.

Liver stiffness assessed by transient elastography in patients with β thalassaemia major

RATIONALE FOR THE STUDY

This cross-sectional multicenter study was conducted to investigate any difference in liver stiffness measurements (LSM), evaluated by transient elastography, between patients affected by β thalassaemia major, with and without hepatitis C virus (HCV) infection, and healthy blood donors (controls). Secondary aim was to assess any correlation between transient elastography and serum ferritin, liver magnetic resonance imaging (MRI) T2* or superconductive quantum interference device (SQUID) liver susceptometry values.

MATERIALS AND METHODS

The study involved three centers. Transient elastography and MRI T2* examinations were performed in all centers. SQUID liver susceptometry was performed in center1 and center2. T-test for independent data or Mann-Whitney U test was used to analyse differences between two groups. Univariate Pearson's r coefficient was used to test correlations between liver stiffness measurements and all other variables.

RESULTS

In a study with 119 patients and 183 controls, patients who had never been infected with HCV showed significantly higher LSMs than controls [5.7 (95% CI, 5.2-6.2) kPa vs. 4.3 (95% CI, 4.1-4.4) kPa, p < 0.0001]. A moderate correlation between LSMs and ferritin values, adjusted for gender and age, was found in patients (r = 0.49, p < 0.0001) but not in controls (r = -0.22, p = 0.6). No correlation between LSMs and MRI T2* or SQUID liver susceptometry values was observed. In conclusion, compared to controls β thalassaemia major patients had a significant increase in LSMs independently from HCV infection.

Association of sustained virologic response with reduced progression to liver cirrhosis in elderly patients with chronic hepatitis C

Objective

We studied the effect of sustained virologic response (SVR) after treatment with pegylated-interferon (PEG-IFN) plus ribavirin on the development of liver cirrhosis in elderly patients with chronic hepatitis C (CHC).

Patients and methods

This retrospective study enrolled 145 elderly CHC patients (aged ≥65 years) who were treatment-naïve and were treated with PEG-IFN plus ribavirin for 6 months between January 2005 and December 2011. Abdominal sonography was performed and liver biochemistry was studied at baseline, at the end of treatment, and every 3–6 months thereafter. The development of liver cirrhosis and related complications was evaluated at the follow-ups. The aspartate aminotransferase-to-platelet ratio index was used as a noninvasive maker for fibrosis.

Results

The mean patient age was 69.1±3.3 years, and the average follow-up time was 5.5 years (standard deviation: 2.5 years, range: 1.1–12.3 years). Ninety-five patients (65.5%) achieved SVR, and 26 (17.9%) discontinued treatment. Twenty-seven patients (18.6%) developed liver cirrhosis after treatment. Patients without SVR had significantly greater risk of liver cirrhosis than those with SVR (hazard ratio [HR]: 3.39, 95% confidence interval [CI]: 1.312–8.761, P=0.012). The difference in 3-year cumulative incidence of liver cirrhosis was 24.8% greater for patients without SVR (35.2%, 95% CI: 13.0–57.5, P=0.012) compared with those with SVR (10.4%, 95% CI: 3.1–17.7). There was a trend of a higher baseline aspartate aminotransferase-to-platelet ratio index score in patients who progressed to liver cirrhosis compared with those who did not progress (2.1±1.2 vs 1.6±1.3, P=0.055), but the difference failed to reach significance by Cox regression (adjusted HR: 1.285, 95% CI: 0.921–1.791, P=0.14).

Conclusion

An SVR following PEG-IFN combination treatment can reduce the risk of liver cirrhosis in elderly CHC patients.

Evaluation of Transient Elastography, Acoustic Radiation Force Impulse Imaging (ARFI), and Enhanced Liver Function (ELF) Score for Detection of Fibrosis in Morbidly Obese Patients

BACKGROUND

Liver fibrosis induced by non-alcoholic fatty liver disease causes peri-interventional complications in morbidly obese patients. We determined the performance of transient elastography (TE), acoustic radiation force impulse (ARFI) imaging, and enhanced liver fibrosis (ELF) score for fibrosis detection in bariatric patients.

PATIENTS AND METHODS

41 patients (median BMI 47 kg/m2) underwent 14-day low-energy diets to improve conditions prior to bariatric surgery (day 0). TE (M and XL probe), ARFI, and ELF score were performed on days -15 and -1 and compared with intraoperative liver biopsies (NAS staging).

RESULTS

Valid TE and ARFI results at day -15 and -1 were obtained in 49%/88% and 51%/90% of cases, respectively. High skin-to-liver-capsule distances correlated with invalid TE measurements. Fibrosis of liver biopsies was staged as F1 and F3 in n = 40 and n = 1 individuals. However, variations (median/range at d-15/-1) of TE (4.6/2.6-75 and 6.7/2.9-21.3 kPa) and ARFI (2.1/0.7-3.7 and 2.0/0.7-3.8 m/s) were high and associated with overestimation of fibrosis. The ELF score correctly classified 87.5% of patients.

CONCLUSION

In bariatric patients, performance of TE and ARFI was poor and did not improve after weight loss. The ELF score correctly classified the majority of cases and should be further evaluated.

The Role of Ultrasound Elasticity Imaging in Predicting Ileal Fibrosis in Crohn's Disease Patients

BACKGOUND

Bowel wall fibrosis is associated with a complicated disease behavior in patients with Crohn's disease (CD). The quantitative assessment of fibrosis severity in CD-affected bowel can help clinical decision making. Our aim was to evaluate the feasibility, reliability, and reproducibility of ultrasound elasticity imaging (UEI) toward the assessment of ileal fibrosis in CD patients.

METHODS

Twenty-three consecutive patients with ileal or ileocolonic CD, elected for surgical resection of the terminal ileum, underwent bowel ultrasound and UEI. Twenty inflammatory CD patients without complications were enrolled as controls. Bowel wall stiffness was evaluated with UEI by means of color scale and quantitative strain ratio measurement. The severity of bowel wall fibrosis and inflammation were evaluated on histological sections by semiquantitative and quantitative image analysis and used as a reference standard.

RESULTS

The UEI strain ratio measurement was significantly correlated with the severity of bowel fibrosis at both semiquantitative and quantitative histological image analysis: it was characterized by an excellent discriminatory ability for severe bowel fibrosis (area under the receiver operating characteristic curve: 0.917; 95% confidence interval, 0.788-1.000). UEI strain ratio measurements were characterized by an excellent interrater agreement. At multivariate analysis, bowel wall fibrosis proved the only independent determinant of the strain ratio. The ileal strain ratio of inflammatory CD patients was significantly lower than in operated CD patients with severe fibrosis.

CONCLUSIONS

UEI can be used to assess ileal fibrosis in CD patients.

Assessment of liver fibrosis in chronic hepatitis B using acoustic structure quantification: quantitative morphological ultrasound

OBJECTIVES

To prospectively investigate the usefulness of acoustic structure quantification (ASQ) for noninvasive assessment of liver fibrosis in patients with chronic hepatitis B (CHB).

METHODS

Consecutive patients with CHB scheduled for liver biopsy or partial liver resection underwent standardized ASQ examinations. The ASQ parameter, named focal disturbance (FD) ratio, were compared with METAVIR scores. The analysis was based on receiver operating characteristic (ROC) curves and multiple regression analysis.

RESULTS

A total of 114 patients were enrolled in the final analysis. The area under the ROC curve for the FD ratio was 0.84 for significant fibrosis (≥ F2), 0.86 for severe fibrosis (≥ F3), and 0.83 for cirrhosis (= F4). The optimal cutoff values for the FD ratio were 0.25, 0.30 and 0.50 for fibrosis stages ≥ F2, ≥ F3 and = F4, respectively. The prevalence of a difference of at least two stages between the FD ratio and the histological stage was 12.3 % (14 of 114). The fibrosis stage (P < 0.001), degree of steatosis (P < 0.001) were independent factors associated with the FD ratio.

CONCLUSIONS

FD ratio should be an effective noninvasive imaging biomarker for the assessment of liver fibrosis in patients with CHB.

KEY POINTS

• Focal disturbance (FD) ratio increased with the increasing histological fibrosis stages. • FD ratio showed promising diagnostic accuracy in assessing liver fibrosis. • Degree of fibrosis and steatosis were independent factors associated with FD ratio.

Impact factors and the optimal parameter of acoustic structure quantification in the assessment of liver fibrosis

The aims of the present study are to assess the impact factors on acoustic structure quantification (ASQ) ultrasound and find the optimal parameter for the assessment of liver fibrosis. Twenty healthy volunteers underwent ASQ examinations to evaluate impact factors in ASQ image acquisition and analysis. An additional 113 patients with liver diseases underwent standardized ASQ examinations, and the results were compared with histologic staging of liver fibrosis. We found that the right liver displayed lower values of ASQ parameters than the left (p = 0.000-0.021). Receive gain experienced no significant impact except gain 70 (p = 0.193-1.000). With regard to different diameter of involved vessels in regions of interest, the group ≤2.0 mm differed significantly with the group 2.1-5.0 mm (p = 0.000-0.033) and the group >5.0 mm (p = 0.000-0.062). However, the region of interest size (p = 0.438-1.000) and depth (p = 0.072-0.764) had no statistical impact. Good intra- and inter-operator reproducibilities were found in both image acquisitions and offline image analyses. In the liver fibrosis study, the focal disturbance ratio had the highest correlation with histologic fibrosis stage (r = 0.67, p < 0.001). In conclusion, the testing position, receive gain and involved vessels were the main factors in ASQ examinations and focal disturbance ratio was the optimal parameter in the assessment of liver fibrosis.

Ultrasound imaging of the liver and bile ducts - expectations of a clinician

Since diseases of the liver and bile ducts are common, a clinician is faced by the need to implement an appropriate diagnostic process. It is necessary to apply diagnostic methods that enable appropriate assessment of the most common pathologies of the liver, i.e. fibrosis, steatosis and focal lesions, as well as initial assessment of the bile ducts. These goals can be achieved using ultrasound methods based on conventional sonography, contrast-enhanced sonography and elastography. The assessment of fatty liver and bile duct dilatation using ultrasound reaches satisfactory levels of sensitivity and specificity. The usage of contrast agents enables unambiguous differentiation between benign and malignant focal lesions, frequently allowing them to be identified accurately without the assistance of other imaging modalities. Elastography has enabled reliable assessment of liver fibrosis. Its results are comparable to those of the standard method, i.e. liver biopsy.