Noninvasive diagnosis of the degree of hepatic fibrosis using ultrasonography in patients with chronic liver disease due to hepatitis C virus

Mass Cytometry Study on Hepatic Fibrosis and Its Drug-Induced Recovery Using Mouse Peripheral Blood Mononuclear Cells

The number of patients with liver diseases has increased significantly with the progress of global industrialization. Hepatic fibrosis, one of the most common liver diseases diagnosed in many developed countries, occurs in response to chronic liver injury and is primarily driven by the development of inflammation. Earlier immunological studies have been focused on the importance of the innate immune response in the pathophysiology of steatohepatitis and fibrosis, but recently, it has also been reported that adaptive immunity, particularly B cells, plays an essential role in hepatic inflammation and fibrosis. However, despite recent data showing the importance of adaptive immunity, relatively little is known about the role of B cells in the pathogenesis of steatohepatitis fibrosis. In this study, a single-cell-based, high-dimensional mass cytometric investigation of the peripheral blood mononuclear cells collected from mice belonging to three groups [normal chow (NC), thioacetamide (TAA), and 11beta-HSD inhibitor drug] was conducted to further understand the pathogenesis of liver fibrosis through reliable noninvasive biomarkers. Firstly, major immune cell types and their population changes were qualitatively analyzed using UMAP dimensionality reduction and two-dimensional visualization technique combined with a conventional manual gating strategy. The population of B cells displayed a twofold increase in the TAA group compared to that in the NC group, which was recovered slightly after treatment with the 11beta-HSD inhibitor drug. In contrast, the populations of NK cells, effector CD4⁺ T cells, and memory CD8⁺ T cells were significantly reduced in the TAA group compared with those in the NC group. Further identification and quantification of the major immune cell types and their subsets were conducted based on automated clustering approaches [PhenoGraph (PG) and FlowSOM]. The B-cell subset corresponding to PhenoGraph cluster PG#2 (CD62L^highCD44^highLy6c^high B cells) and PG#3 (CD62L^highCD44^highLy6c^low B cell) appears to play a major role in both the development of hepatic fibrosis and recovery via treatment, whereas PG#1 (CD62L^lowCD44^highLy6c^low B cell) seems to play a dominant role in the development of hepatic fibrosis. These findings provide insights into the roles of cellular subsets of B cells during the progression of, and recovery from, hepatic fibrosis.

Gastric artery embolization: studying the effects of catheter type and injection method on microsphere distributions within a benchtop arterial model

Aims

The objective of the study is to investigate the effect of catheter type and injection method on microsphere distributions, specifically vessel targeting accuracy.

Materials and methods

The study utilized three catheter types (a standard end-hole micro-catheter, a Surefire anti-reflux catheter, and an Endobar occlusion balloon catheter) and both manual and computer-controlled injection schemes. A closed-loop, dynamically pressurized surrogate arterial system was assembled to replicate arterial flow for bariatric embolization procedures. Four vessel branches immediately distal to the injection site were targeted for embolization. Embolic microspheres were injected into the model using these  three catheter types and both manual and computer-controlled injections.

Results

Across all injection methods, the catheter effect on the proportion of microspheres to target vessels (vs. non-target vessels) was significant (p = 0.005). The catheter effect on the number of non-target vessels embolized was nearly significant (p = 0.059). Across all catheter types, the injection method effect was not statistically significant for either of two outcome measures (percent microspheres to target vessels: p = 0.265, number of non-target vessels embolized: p = 0.148).

Conclusion

Catheter type had a significant effect on targeting accuracy across all injection methods. The Endobar catheter exhibited a higher targeting accuracy in pairwise comparisons with the other two injection catheters across all injection schemes and when considering the Endobar catheter with the manifold injection method vs. each of the catheters with the manual injection method; the differences were significant in three of four analyses. The injection method effect was not statistically significant across all catheter types and when considering the Endobar catheter/Endobar manifold combination vs. Endobar catheter injections with manual and pressure-replicated methods.

Differentiating solid, non-macroscopic fat containing, enhancing renal masses using fast Fourier transform analysis of multiphase CT

OBJECTIVE

To test the feasibility of two-dimensional fast Fourier transforms (FFT)-based imaging metrics in differentiating solid, non-macroscopic fat containing, enhancing renal masses using contrast-enhanced CT images. We quantify image-based intratumoral textural variations (indicator of tumor heterogeneity) using frequency-based (FFT) imaging metrics.

METHODS

In this Institutional Review Board approved, Health Insurance Portability and Accountability Act -compliant, retrospective case-control study, we evaluated 156 patients with predominantly solid, non-macroscopic fat containing, enhancing renal masses identified between June 2009 and June 2016. 110 cases (70%) were malignant RCC, including clear cell, papillary and chromophobe subtypes and, 46 cases (30%) were benign renal masses: oncocytoma and lipid-poor angiomyolipoma. Whole lesions were manually segmented using Synapse 3D (Fujifilm, CT) and co-registered from the multiphase CT acquisitions for each tumor. Pathological diagnosis of all tumors was obtained following surgical resection. Matlab function, FFT2 was used to perform the image to frequency transformation.

RESULTS

A Wilcoxon rank sum test showed that FFT-based metrics were significantly (p < 0.005) different between 1. benign vs malignant renal masses, 2. oncocytoma vs clear cell renal cell carcinoma and 3. oncocytoma vs lipid-poor angiomyolipoma. Receiver operator characteristics analysis revealed reasonable discrimination (area under the curve >0.7, p < 0.05) within these three groups of comparisons.

CONCLUSION

In combination with other metrics, FFT-metrics may improve patient management and potentially help differentiate other renal tumors. Advances in knowledge: We report for the first time that FFT-based metrics can differentiate between some solid, non-macroscopic fat containing, enhancing renal masses using their contrast-enhanced CT data.

Nonalcoholic fatty liver with a hepatic arterial buffer response strongly associated with future metabolic disease

A change in hepatic blood flow caused by the hepatic arterial buffer response (HABR) occurs as fatty liver disease progress. The aim of this longitudinal cohort study was to investigate whether fatty liver with the HABR induces metabolic disorders. In 2009 and 2010, 494 (89.5%) participants were enrolled. The median follow‐up duration was 5.0 (interquartile range, 3.9‐6.0) years. The hazard ratios of fatty liver with the HABR for incident metabolic disorders were assessed by Cox proportional hazard models. A non–fatty liver group (non‐FL group, hepatorenal echo intensity ratio <1.12), a fatty liver without portal hypertension (FL group, hepatorenal echo intensity ratio ≥1.12 and ratio of the maximal blood velocity in the right hepatic artery to maximal blood velocity in the right portal vein <3.1) group, and a fatty liver with portal hypertension (FL‐HABR group, hepatorenal echo intensity ratio ≥1.12 and ratio of the maximal blood velocity in the right hepatic artery to maximal blood velocity in the right portal vein ≥3.1) group were defined based on echo intensity and Doppler ultrasonography. Fatty liver with and without the HABR was significantly associated with the incidence of diabetes on multivariate analysis (non‐FL versus FL group, hazard ratio, 3.36; 95% confidence interval, 1.05‐12.85; FL versus FL with the HABR group, HR, 2.68; 95% confidence interval, 1.28‐6.04). With respect to the incidence of hypertension and dyslipidemia, only FL with the HABR was a significant factor (hypertension, non‐FL versus FL, P = 0.874, FL versus FL‐HABR, P = 0.016, non‐FL versus FL‐HABR, P = 0.023; dyslipidemia, non‐FL versus FL, P = 0.311, FL versus FL‐HABR, P = 0.194, non‐FL versus FL‐HABR, P = 0.038). Conclusion: Fatty liver with the HABR is a high‐risk condition for metabolic diseases. (Hepatology Communications 2017;1:623–633)

Innovation in catheter design for intra-arterial liver cancer treatments results in favorable particle-fluid dynamics

Background

Liver tumors are increasingly treated with radioembolization. Here, we present first evidence of catheter design effect on particle-fluid dynamics and downstream branch targeting during microsphere administrations.

Materials and methods

A total of 7 experiments were performed in a bench-top model of the hepatic arterial vasculature with recreated hemodynamics. Fluorescent microspheres and clinically used holmium microspheres were administered with a standard microcatheter (SMC) and an anti-reflux catheter (ARC) positioned at the same level along the longitudinal vessel axis. Catheter-related particle flow dynamics were analyzed by reviewing video recordings of UV-light illuminated fluorescent microsphere administrations. Downstream branch distribution was analyzed by quantification of collected microspheres in separate filters for two first-order branches. Mean deviation from a perfectly homogenous distribution (DHD) was used to compare the distribution homogeneity between catheter types.

Results

The SMC administrations demonstrated a random off-centered catheter position (in 71 % of experiments), and a laminar particle flow pattern with an inhomogeneous downstream branch distribution, dependent on catheter position and injection force. The ARC administrations demonstrated a fixed centro-luminal catheter position, and a turbulent particle flow pattern with a more consistent and homogenous downstream branch distribution. Quantitative analyses confirmed a significantly more homogeneous distribution with the ARC; the mean DHD was 40.85 % (IQR 22.76 %) for the SMC and 15.54 % (IQR 6.46 %) for the ARC (p = 0.047).

Conclusion

Catheter type has a significant impact on microsphere administrations in an in-vitro hepatic arterial model. A within-patient randomized controlled trial has been initiated to investigate clinical catheter-related effects during radioembolization treatment.

Electronic supplementary material

The online version of this article (doi:10.1186/s13046-015-0188-8) contains supplementary material, which is available to authorized users.

Selective internal radiation therapy: quantifying distal penetration and distribution of resin and glass microspheres in a surrogate arterial model

PURPOSE

To experimentally investigate the effects of microsphere density and diameter on distal penetration.

MATERIALS AND METHODS

A surrogate hepatic arterial system was developed to replicate the hemodynamics (pressures, flow rates, pulsatile flow characteristics) and anatomic geometry (vessel diameters) proximal and distal to the microsphere injection point. A planar tumor model, placed distal to the injection point, allowed visualization of deposited microspheres. Bland resin and glass microspheres, with physical characteristics approximating the characteristics of commercially available products, were injected into the surrogate system. Microsphere type, injection rate, systemic flow rate, and tumor model inclination were varied among tests (glass, n = 7; resin, n = 6) with replicates for 2 conditions. After injection, 254 micrographs were obtained at previously defined locations throughout the tumor model to document microsphere distributions. Average microsphere distributions and mass measurements of microspheres collected at the tumor outlet were analyzed to quantify distal penetration for each case.

RESULTS

Across all test conditions, average penetration depths of resin microspheres were higher compared with glass microspheres (45.1 cm ± 11.8 vs 22.3 cm ± 9.9). The analysis of variance indicated that the observed difference between microsphere type (glass vs resin) was significant (P = .005, df = 1,2). The observed distance means did not differ significantly across flow rate or inclination angle.

CONCLUSIONS

Penetration depths of resin microspheres were significantly higher than penetration depths of glass microspheres in the surrogate hepatic arterial system.

Clinically severe portal hypertension: role of multi-detector row CT features in diagnosis

BACKGROUND AND AIM

To explore the CT signs which permit estimation of clinically severe portal hypertension (PH) [≥ 12 of hepatic vein pressure gradient (HVPG)].

METHODS

One-hundred and seven consecutive patients who underwent HVPG measurement in the PH group and 52 controls were included. The diameters of main portal vein (øMPV), superior mesenteric vein (øSMV), splenic vein (øSV), and left gastric vein, øMPV/øSV, øSMV/øSV, as well as estimated spleen volumes were evaluated on the CT scan. The grade of varix and ascites were also evaluated semi-quantitatively. We explored the statistically significant CT features related to severe PH and performed a logistic regression analysis for an estimation model for severe PH.

RESULTS

øMPV/øSV and øSMV/øSV tended to gradually increase as the PH became severer, and the difference between severe and not severe groups was statistically significant (p = 0.015 and 0.038, respectively). According to the regression analysis, øSMV/øSV and the grade of esophageal varix and ascites were finally included as related variables for predicting severe PH. The odds ratio (OR) of øSMV/øSV was 4.596, and large esophageal varix (OR 4.135) and mild (OR 3.051) and large amount of ascites (OR 21.781) were statistically significantly related to severe PH.

CONCLUSION

Changing diameters of portal system, the grades of esophageal varices and ascites on multi-detector row computed tomography might be indicative features for clinically severe PH.

Quantifying tissue mechanical properties using photoplethysmography

Photoplethysmography (PPG) is a non-invasive optical method that can be used to detect blood volume changes in the microvascular bed of tissue. The PPG signal comprises two components; a pulsatile waveform (AC) attributed to changes in the interrogated blood volume with each heartbeat, and a slowly varying baseline (DC) combining low frequency fluctuations mainly due to respiration and sympathetic nervous system activity. In this report, we investigate the AC pulsatile waveform of the PPG pulse for ultimate use in extracting information regarding the biomechanical properties of tissue and vasculature. By analyzing the rise time of the pulse in the diastole period, we show that PPG is capable of measuring changes in the Young's Modulus of tissue mimicking phantoms with a resolution of 4 KPa in the range of 12 to 61 KPa. In addition, the shape of the pulse can potentially be used to diagnose vascular complications by differentiating upstream from downstream complications. A Windkessel model was used to model changes in the biomechanical properties of the circulation and to test the proposed concept. The modeling data confirmed the response seen in vitro and showed the same trends in the PPG rise and fall times with changes in compliance and vascular resistance.

Biomarkers of liver fibrosis

Liver fibrosis is the final common pathway for almost all causes of chronic liver injury. Liver fibrosis is now known to be a dynamic process having significant potential for resolution. Therefore, fibrosis prediction is an essential part of the assessment and management of patients with chronic liver disease. As such, there is strong demand for reliable liver biomarkers that provide insight into disease etiology, diagnosis, therapy, and prognosis in lieu of more invasive approaches such as liver biopsy. Current diagnostic strategies range from use of serum biomarkers to more advanced imaging techniques including transient elastography and magnetic resonance imaging. In addition to these modalities, there are other approaches including the use of novel, but yet to be validated, biomarkers. In this chapter, we discuss the biomarkers of liver fibrosis including the use of invasive and noninvasive biomarkers and disease-specific biomarkers in various chronic liver diseases.

Real-time tissue elastography for evaluation of hepatic fibrosis and portal hypertension in nonalcoholic fatty liver diseases

The aim of this study was to prospectively measure liver stiffness with real-time tissue elastography in patients with nonalcoholic fatty liver diseases (NAFLD) and to compare the result with the clinical assessment of fibrosis using histological stage. One hundred and eighty-one prospectively enrolled patients underwent real-time tissue elastography, with the first 106 being analyzed as the training set and the remaining 75 being evaluated as the validation set. Hepatic and splenic elastic ratios were calculated and compared with stage of histological fibrosis. Portal hypertension (PH) was assessed. Real-time tissue elastography cut-off values by stage in the training set were 2.47 for F1, 2.67 for F2, 3.02 for F3, and 3.36 for F4. Using these cut-off values, the diagnostic accuracy of hepatic fibrosis in the validation set was 82.6%-96.0% in all stages. Only portal fibrosis correlated with the hepatic elastic ratio by multivariate analysis. The area under the receiver operating characteristic curve of elastic ratio better correlated than serum fibrosis markers in both early and advanced fibrosis stages. Patients with PH, defined by splenic elasticity, had early fibrosis. Patients with severe PH were found only in the group with cirrhosis.

CONCLUSION

Real-time tissue elastography is useful in evaluating hepatic fibrosis and PH in patients with NAFLD.

Acoustic liver biopsy in patients with hepatitis C and advanced liver fibrosis using endoscopic ultrasound

BACKGROUND

Transabdominal ultrasound cannot be used to quantitate fibrosis in patients with advanced liver fibrosis due to variability in the abdominal wall thickness and composition. This variability can be eliminated by using endoscopic ultrasound.

AIM

The purpose of this study was to determine the amount of fibrosis in the liver of hepatitis C patients with advanced fibrosis using endoscopic ultrasound.

METHODS

Endoscopic ultrasound images of the liver were recorded by keeping the gain, contrast, frequency, magnification and acoustic power constant on the ultrasound processor. Videotaped images of the liver were digitized on Image-Pro Plus software. Using adobe Photoshop, a histogram was produced to quantitate the luminosity of the five areas of interest per image. Quantification of the ultrasound images were done by two independent investigators blinded to the Ishak liver fibrosis score. The mean luminosity of the ultrasound images were compared with the Ishak fibrosis score. The study was performed in seven patients (mean age 54 years; 3 male, 4 female) with hepatitis C and advanced liver fibrosis.

RESULTS

The correlation between the two independent investigators for the ultrasound images was 0.93. The correlation between the mean luminosity on ultrasound images to the Ishak fibrosis score was r = 0.77, r = 0.72 and r = 0.73 for the most hyperechoic area of interest, total hyperechoic area and for the entire liver, respectively.

CONCLUSION

A new technique was developed that uses endoscopic ultrasound to evaluate the degree of fibrosis in patients with advanced liver fibrosis. There is a good correlation between the luminosity on endoscopic ultrasound and the Ishak fibrosis score.

Splenic elasticity measured with real-time tissue elastography is a marker of portal hypertension

PURPOSE

To prospectively correlate spleen elasticity and degree of portal hypertension estimated with the hepatic venous pressure gradient (HVPG) and to evaluate splenic elasticity as a predictor of gastroesophageal varices.

MATERIALS AND METHODS

The institutional review board approved this study, and patients provided written informed consent. In a pilot study of 60 patients with chronic liver damage, the authors measured liver and spleen elasticity with real-time tissue elastography (RTE), obtained serum markers related to fibrosis, examined hepatic and splenic blood flow with duplex Doppler ultrasonography, estimated HVPG, and performed upper gastrointestinal endoscopy. Then, with use of thresholds determined in the pilot study, the authors conducted a validation trial with another 210 patients, performing all studies except the measurement of HPVG. The relationship between HVPG and the other parameters was analyzed. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) in the diagnosis of gastroesophageal varices were calculated by using cutoff values obtained from receiver operating characteristic curves.

RESULTS

Among the parameters associated with HVPG, correlation was closest with splenic elasticity (R = 0.854, P < .0001). When 8.24 was selected as the cutoff of splenic elasticity for predicting HVPG of more than 10 mm Hg, the accuracy of diagnosing gastroesophageal varix was 90% (sensitivity, 96%; specificity, 85%; PPV, 83%; NPV, 97%). The results of the validation trial showed that the 8.24 cutoff for splenic elasticity was associated with a diagnostic accuracy of 94.8% (sensitivity, 98%; specificity, 93.8%; PPV, 82.1%; NPV, 99.4%) for gastroesophageal varices.

CONCLUSION

Splenic elasticity determined with RTE is the most closely associated parameter for evaluating HVPG and is useful as a clinical marker of portal hypertension and a predictive marker of gastroesophageal varices.

A brief review on molecular, genetic and imaging techniques for HCV fibrosis evaluation

Background

Chronic HCV is one of the major causes of morbidity and mortality in the present day world. The assessment of disease progression not only provides useful information for diagnosis and therapeutic supervision judgment but also for monitoring disease. Different invasive and non invasive methods are applied to diagnose the disease from initial to end stage (mild fibrosis to cirrhosis). Although, liver biopsy is still considered as gold standard to identify liver histological stages, an assessment of the disease development based on non-invasive clinical findings is also emerging and this may replace the need of biopsy in near future. This review gives brief insight on non-invasive methods currently available for predicting liver fibrosis in HCV with their current pros and cons to make easier for a clinician to choose better marker to assess liver fibrosis in HCV infected patients.

Methods

More than 200 studies regarding invasive and noninvasive markers available for HCV liver disease diagnosis were thoroughly reviewed. We examined year wise results of these markers based on their sensitivity, specificity, PPV, NPV and AUROCs.

Results

We found that in all non-invasive serum markers for HCV, FibroTest, Forn's Index, Fibrometer and HepaScore have high five-year predictive value but with low AUROCs (0.60~0.85) and are not comparable to liver biopsy (AUROC = 0.97). Even though from its beginning, Fibroscan is proved to be best with high AUROCs (> 0.90) in all studies, no single noninvasive marker is able to differentiate all fibrosis stages from end stage cirrhosis. Meanwhile, specific genetic markers may not only discriminate fibrotic and cirrhotic liver but also differentiate individual fibrosis stages.

Conclusions

There is a need of marker which accurately determines the stage based on simplest routine laboratory test. Genetic marker in combination of imaging technique may be the better non invasive diagnostic method in future.

Liver contrast enhanced ultrasound perfusion imaging in the evaluation of chronic hepatitis C fibrosis: preliminary results

We wanted to determine whether liver contrast-enhanced ultrasound (CEUS)-derived peak signal intensity (PSI) and peak signal intensity/time (PIT) predict liver fibrosis in chronic hepatitis C (CHC). Forty-nine patients with CHC (METAVIR classification) and 10 control subjects were included in the study. After a bolus of 2.4 mL SonoVue (Bracco Imaging, Milan, Italy) solution was injected into a peripheral vein, the right lobe of the liver containing the right portal vein was scanned in a transverse section. Two-dimensional sonography was performed using the Philips iU22 ultrasound system (Philips Healthcare, Best, the Netherlands). A 1.0-5.0-MHz (C5-1) wideband convex transducer was used, applying the following settings in all cases. Regions of interest were manually drawn over the right liver lobe and over the portal vein (PV). Liver parenchyma PSI (LPpsi) and PIT (LPpit), portal vein PSI (PVpsi) and PIT (PVpit) were automatically calculated. δPSI was defined as the difference between PVpsi and LPpsi. A significant correlation was observed between PA(PSI) and fibrosis scores. When patients were stratified according to their LPpsi, a significant difference was achieved only between patients with fibrosis score 0-1 vs. 2-3 and 2 vs. 4. Statistically significant differences between all fibrosis scores, except 0 vs. 1 and 3 vs. 4 were observed when δPSI was used to stratify patients. Overall diagnostic accuracy of LPpsi and δPSI measurement for severe fibrosis by area under the receiving operator characteristic curve analysis was, respectively, 0.87 and 0.88. We suggest that liver CEUS perfusion could have the potential to be used as a complementary tool for the evaluation of liver fibrosis. However, further large-scale studies are required to accurately assess its accuracy in the evaluation of liver fibrosis.

Value of duplex doppler ultrasonography in non-invasive assessment of children with chronic liver disease

AIM: To investigate the value of duplex Doppler ultrasonography (US) in the assessment of the hemodynamics of the portal and hepatic veins in a cohort of children with chronic liver disease (CLD) and to detect any relationship between the US changes, etiology and severity (or stage) of CLD.

METHODS: We prospectively enrolled 25 children with biopsy-proven CLD. Thirteen had cirrhosis (aged 8.9 ± 2.0 years) and 12 had chronic hepatitis (aged 9.3 ± 2.3 years). Gray scale and color-coded duplex Doppler US were performed for all, as well as 30 healthy age and sex-matched controls. Findings were correlated with clinical, laboratory and histopathological characteristics.

RESULTS: Prominent caudate lobe was detected in 100% of cirrhotics, but none of the chronic hepatitis or controls. Thickened lesser omentum and loss of the triphasic waveform of the hepatic vein were present in 69.2% and 53.8% of cirrhotics vs 33.3% and 8.3% of chronic hepatitis respectively. Portal vein flow velocity was significantly lower (P < 0.0001) and the congestion index was significantly higher (P < 0.005) in both patient groups compared to controls. Child-Pugh’s staging showed a positive correlation with both abnormal hepatic vein waveform and direction of portal blood flow; and a negative correlation with both hepatic and portal vein flow velocities. No correlation with the etiology of CLD could be detected.

CONCLUSION: Duplex Doppler added to grayscale US can detect significant morphologic and portal hemodynamic changes that correlate with the severity (stage) of CLD, but not with etiology.

Systematic review: non-invasive methods of fibrosis analysis in chronic hepatitis C

BACKGROUND

Accurate determination of the presence and degree of liver fibrosis is essential for prognosis and for planning treatment of patients with chronic hepatitis C virus (HCV). Non-invasive methods of assessing fibrosis have been developed to reduce the need for biopsy.

AIM

To perform a review of these non-invasive measures and their ability to replace biopsy for assessing hepatic fibrosis in patients with chronic HCV.

METHODS

A systematic review of PUBMED and EMBASE was performed through 2008 using the following search terms: HCV, liver, elastography, hepatitis, Fibroscan, SPECT, noninvasive liver fibrosis, ultrasonography, Doppler, MRI, Fibrotest, Fibrosure, Actitest, APRI, Forns and breath tests, alone or in combination.

RESULTS

We identified 151 studies: 87 using biochemical, 57 imaging and seven breath tests either alone or in combination.

CONCLUSIONS

Great strides are being made in the development of accurate non-invasive methods for determination of fibrosis. Although no single non-invasive test or model developed to date can match that information obtained from actual histology (i.e. inflammation, fibrosis, steatosis), combinations of two modalities of non-invasive methods can reliably differentiate between minimal and significant fibrosis, and thereby avoid liver biopsy in a significant percentage of patients.

Can imaging modalities diagnose and stage hepatic fibrosis and cirrhosis accurately?

The accurate diagnosis and staging of hepatic fibrosis is crucial for prognosis and treatment of liver disease. The current gold standard, liver biopsy, cannot be used for population-based screening, and has well known drawbacks if used for monitoring of disease progression or treatment success. Our objective was to assess performance and promise of radiologic modalities and techniques as alternative, noninvasive assessment of hepatic fibrosis. A systematic review was conducted. Six hundred twenty-eight studies were identified via electronic search. One hundred fifty-three papers were reviewed. Most described techniques that could differentiate between cirrhosis or severe fibrosis and normal liver. Accurate staging of fibrosis or diagnosis of mild fibrosis was often not achievable. Ultrasonography is the most common modality used in the diagnosis and staging of hepatic fibrosis. Elastographic measurements, either ultrasonography-based or magnetic resonance-based, and magnetic resonance diffusion weighted imaging, show the most promise for accurate staging of hepatic fibrosis. Most currently available imaging techniques can detect cirrhosis or significant fibrosis reasonably accurately. However, to date only magnetic resonance elastography has been able to stage fibrosis or diagnose mild disease. Utrasonographic elastography and magnetic resonance diffusion weighted appear next most promising.

A non-invasive algorithm accurately predicts advanced fibrosis in hepatitis C: a comparison using histology with internal-external validation

BACKGROUND/AIMS

Biochemical tests and ultrasonography (US) are useful in the non-invasive assessment of liver fibrosis in patients with chronic hepatitis C (CH-C); however histology remains the reference standard. This multicenter, cross-sectional cohort study evaluated the accuracy of APRI (AST-to-platelet-ratio-index) and liver surface ultrasound nodularity (LSN), singularly and sequentially combined in an algorithm, in diagnosing advanced fibrosis (i.e. METAVIR F3,F4), to derive a prediction rule to confirm or exclude F3,F4.

METHODS

Four hundred and thirty consecutive CH-C patients with elevated ALT, grouped into a first cohort (training set), and an internal and an external validation cohort, were studied. APRI and LSN were compared to liver biopsy and sequentially combined in order to obtain a predictive rule for advanced fibrosis METAVIR F3,F4.

RESULTS

LSN was negative and APRI < or = 1 in 185/430 patients, whereas LSN was positive and APRI>2 in 46/430 cases, with a 94% diagnostic accuracy for presence/absence of F3, F4, respectively. In a further 60/430 patients, F3,F4 was detected with an accuracy of 83%. In the remaining cases no classification was possible.

CONCLUSIONS

An algorithm based on APRI and LSN confirms or excludes F3,F4 in 54% of CH-C patients with elevated ALT and suggests a highly probable diagnosis in a further one-sixth of patients, thus rendering liver biopsy unnecessary in these patients.

Hepatitis C virus reinfection in liver transplant patients: evaluation of liver damage progression with echo-color Doppler

Liver transplant recipients are a model of rapid progression of hepatitis C virus (HCV)-related liver disease, from normal to cirrhosis. The aim of the study was the analysis of the relationship between portohepatic hemodynamics and modification in liver histology during the progression of HCV liver disease after transplant. Patients transplanted for HCV cirrhosis were considered for the study. At least every 6-12 months, the portal blood flow velocity, hepatic and splenic pulsatility indices, and a portal hypertensive index (obtained from the combination of the portal blood velocity and splenic pulsatility index) were measured with echo-Doppler. Liver biopsy was performed whenever necessary. The time course of echo-Doppler parameters during the histological progression of the liver disease was analyzed. Posttransplant patients without HCV were included as controls. Forty-nine patients with histology-proven relapse of HCV hepatitis were included in the study. At the onset of recurrent hepatitis, the portal blood flow velocity significantly decreased (P < 0.001), and the splenic pulsatility index increased (P = 0.020), whereas the hepatic pulsatility index remained unchanged. In the following years, in addition to a further slight decrease in the portal blood velocity (P = 0.027), a progressive increase in the hepatic and splenic pulsatility indices was also detected (P = 0.009 and P < 0.0001, respectively). The portal hypertensive index steadily increased with the progression of the disease and was related to the degree of liver fibrosis. In conclusion, the information obtainable from splanchnic Doppler parameters can be used to monitor the progression of liver fibrosis in transplant patients with HCV reinfection.

Ultrasonography in differentiation between chronic viral hepatitis and compensated early stage cirrhosis

AIM

To assess the value of gray scale (GS) and colour Doppler ultrasonography (CDU) in differentiating the progression of chronic viral hepatitis (CVH) and compensated liver cirrhosis (CIR).

METHODS

Seventy-two patients and 32 normal individuals who were used as controls were studied. Forty-four patients suffered from CVH and 28 from CIR. All patients were underwent to liver biopsy. Multiple qualitative and quantitative variables were studied in liver, portal vein (PV), hepatic artery (HA) and spleen with GS and CDU. On the basis of the obtained CDU data, several known indexes were calculated. In addition, alternative indices [PV diameter (D)/time average mean velocity (VTAM), HA/PV VTAM ratio] were calculated and studied.

RESULTS

ROC analysis showed that PV congestion index, PV D/VTAM and HA/PV VTAM indices had the best sensitivity and specificity in discriminating CVH from CIR. Stepwise discriminant analysis showed that 88.9% of the originally grouped cases could be correctly classified by the three qualitative and four quantitative variables selected as statistically significant predictors. Among the CVH patients who underwent to biopsy, statistically significant changes were found in those at fibrosis stage 5 compared to fibrosis stages 1-4.

CONCLUSION

Simple GS and CDU parameters discriminate CVH from CIR. The alternative Doppler indexes can accurately differentiate chronic virus hepatitis from cirrhosis. These indexes can be used in monitoring chronic virus hepatitis and avoiding unnecessary biopsies.

Acoustic liver biopsy using endoscopic ultrasound

BACKGROUND

Transabdominal ultrasound cannot be used to quantitate fibrosis in patients with cirrhosis because of variability in the abdominal wall thickness and variability in the components of the abdominal wall (fat versus muscle). Endoscopic ultrasound through the gastric wall is always at a constant distance, approximately 3 mm, away from the liver when the transducer is just below the gastroesophageal junction, thereby eliminating this variability.

PURPOSE

To differentiate between cirrhotic and noncirrhotic liver using endoluminal ultrasound.

METHODS

Eleven patients without known liver disease and eight patients with cirrhosis underwent endoscopic ultrasound using an Olympus linear ultrasound scope. The gain, contrast, frequency, and acoustic power were kept constant on the Aloka ultrasound processor. Videotaped images of the liver were recorded and then digitized on Image-Pro Plus software. The brightness of the image was adjusted to a standard brightness for each image and an area of interest was chosen using Photoshop 7.0. Vessels and artifacts were eliminated digitally and a histogram was produced using Photoshop to quantitate the pixel density for the area of interest from 0 (black) to 255 (white). Approximately 250,000 pixels were evaluated for each subject. The mean +/- standard deviation (SD) pixel density of the noncirrhotic subjects was evaluated against the cirrhotic patients using a Student unpaired t-test.

RESULTS

The mean echogenecity in patients with cirrhosis was 116.85 and the mean echogenecity in patients without cirrhosis was 92.75 (P < 0.002). The mean standard deviation of the pixel density in patients with cirrhosis was 19.08 and the mean standard deviation of the pixel density in patients without cirrhosis was 13.25 (P < 0.0004). Using these criteria the subjects with cirrhosis were segregated from the noncirrhotic subjects (normal subjects and the subjects with steatosis) with 100% sensitivity and 100% specificity.

CONCLUSION

A new method of evaluating the liver parenchyma (acoustic liver biopsy) that takes advantage of the proximity of the endoscopic ultrasound transducer to the liver and uses commercial image analysis technology that is inexpensive and widely available was developed. This is a preliminary study of this new technology, which demonstrates that endoscopic ultrasound, can be standardized in order to image, analyze, and compare the mean echogenecity and mean standard deviation of the pixel density in the liver in order to distinguish cirrhotic patients from patients without cirrhosis.

Portalsystemic hemodynamic changes in chronic severe hepatitis B: An ultrasonographic study

AIM: To evaluate portalsystemic hemodynamic changes in chronic severe hepatitis B.

METHODS: Hemodynamic parameters included portal vein diameter (PVD), portal vein peak velocity (PVPV), portal vein volume (PVV), spleen length (SPL), spleen vein diameter (SPVD), spleen vein volume (SPVV) and umbilical vein recanalization. They were measured by Color Doppler ultrasonography in 36 patients with chronic severe hepatitis B, compared with 51 normal controls, 61 patients with chronic hepatitis B, 46 patients with compensable cirrhosis, and 36 patients with decompensable cirrhosis.

RESULTS: In the group of chronic severe hepatitis B, PVD (12.38 ± 1.23 mm) was significantly different from the normal control, compensable cirrhosis and decompensable cirrhosis groups (P = 0.000-0.026), but not significantly different from the chronic hepatitis group. PVPV (16.15 ± 3.82 cm/s) dropped more significantly in the chronic severe hepatitis B group than the normal control, chronic hepatitis B and compensable cirrhosis groups (P = 0.000-0.011). PVV (667.53 ± 192.83 mL/min) dropped significantly as compared with the four comparison groups (P = 0.000-0.004). SPL (120.42 ± 18.36 mm) and SPVD (7.52 ± 1.52 mm) were longer in the normal control and chronic hepatitis B groups (P = 0.000-0.009), yet they were significantly shorter than those in the decompensable cirrhosis group (P = 0.000). SPVV (242.51 ± 137.70 mL/min) was also lower than the decompensable cirrhosis group (P = 0.000). The umbilical vein recanalization rate (75%) was higher than the chronic hepatitis B and compensable cirrhosis groups. In the course of progression from chronic hepatitis to decompensable cirrhosis, PVD, SPL and SPVD gradually increased and showed significant differences between every two groups (P = 0.000-0.002).

CONCLUSION: Patients with chronic severe hepatitis B have a tendency to develop acute portal hypertension, resulting in significantly reduced portal vein perfusion. Observation of the portalsystemic hemodynamic changes may be contributed to the disease progression of chronic liver disease.

Doppler ultrasonography of hepatic artery in malignant liver tumors

Hepatic artery is dominant compared to portal vein in liver tumor vascularization. Malignant tumors have uncontrolled growth and spread onto neighbouring tissues through a tumor vascular network. Based on this we discussed the use arterial flow parameters including systolic and diastolic speed, Doppler perfusion index, and resistance index for early detection of liver metastasis. We also discussed possibility to make differential diagnosis from other disease such as arterial stenosis, liver cirrhosis, steatosis using these parameters in better diagnosis confirmation.

FibroIndex, a practical index for predicting significant fibrosis in patients with chronic hepatitis C

Diagnosis of the stage of liver fibrosis in chronic hepatitis C is essential for making a prognosis and deciding on antiviral therapy. In the present study a simple model consisting of routine laboratory tests was constructed and then validated in cross-sectional and longitudinal investigations. Consecutive treatment-naive patients with chronic hepatitis C who had undergone liver biopsy were divided into 2 cohorts: an estimation set (n = 240) and a validation set (n = 120). A longitudinal set consisted of 30 patients who had undergone a liver biopsy twice, before and after IFN treatment. The FibroIndex was derived from the platelet count, AST, and gamma globulin measurements in the estimation set. The areas under the ROC curves of the FibroIndex for predicting significant fibrosis were 0.83 and 0.82 for the validation set, better than those of the Forns index and the aminotransferase-to-platelet ratio index (APRI). Using the best cutoff values, whether significant fibrosis was present was diagnosed with high positive predictive values, and 35% of patients could avoid liver biopsy. In the longitudinal set, there was a significant decrease in the FibroIndex of 14 patients whose fibrosis stage improved, and a significant increase in that of 5 patients whose fibrosis stage deteriorated. Change in the FibroIndex correlated significantly with variation in fibrosis stage. There was no such correlation with the Forns index or the APRI.

CONCLUSION

The FibroIndex is a simple and reliable index for predicting significant fibrosis in chronic hepatitis C and could also be used as a surrogate marker during antifibrotic treatment for chronic hepatitis C.

Noninvasive evaluation of hepatic fibrosis in children with infant hepatitis syndrome

AIM: To elucidate the impact of hemodynamic para-meters on ultrasonography and serum fibrosis markers for the assessment of liver fibrosis in the children with infant hepatitis syndrome (IHS).

METHODS: Forty-one children with IHS and 46 healthy infants were examined by ultrasonography, and several hemodynamic indices such as peak systolic velocity (PSV) and resistant index (RI) of proper hepatic artery (PHA) were measured. Serum fibrosis markers including hyaluronic acid (HA), pre-collagen type-III (PC-III), collagen type IV (C-IV), and laminin (LN) were assayed by radioimmunoassays. In children with IHS, liver tissues were obtained either by ultrasound-guided liver biopsy (n = 35) or in the course of operation (n = 6). The stages of hepatic fibrosis were scored as mild (S₁ and S₂), moderate (S₃), or severe (S₄) according to liver histological diagnosis. Multiple groups comparative and Spearman correlative analyses were carried out.

RESULTS: Histopathologically, 39 children (95.1%) were found to have hepatic fibrosis, 12 of them stage S1 or S2, 12 stage S3, and 15 stage S4. PSV, RI of the PHA, and serum HA showed a consecutive increase from mild to severe hepatic fibrosis and a close positive correlation with hepatic fibrosis in IHS group (r = 0.717, 0.745 and 0.712, respectively, P = 0.001). The Doppler waveform of HV was also positively correlated with the degree of hepatic fibrosis in IHS group (n = 0.783, P < 0.001).

CONCLUSION: Combination of ultrasonic studies on the hepatic hemodynamics with the evaluation of serum HA may provide an indicator for hepatic fibrosis in patients with IHS. This may be a useful noninvasive method for the diagnosis and evaluation of the prognosis of IHS.

Accuracy of a predictive model for severe hepatic fibrosis or cirrhosis in chronic hepatitis C

AIM

To assess the accuracy of a model in diagnosing severe fibrosis/cirrhosis in chronic hepatitis C virus (HCV) infection.

METHODS

The model, based on the sequential combination of the Bonacini score (BS: ALT/AST ratio, platelet count and INR) and ultrasonography liver surface characteristics, was applied to 176 patients with chronic HCV infection. Assuming a pre-test probability of 35%, the model defined four levels of post-test probability of severe fibrosis/cirrhosis: <10% (low), 10-74% (not diagnostic), 75-90% (high) and >90% (almost absolute). The predicted probabilities were compared with the observed patientso distribution according to the histology (METAVIR).

RESULTS

Severe fibrosis/cirrhosis was found in 67 patients (38%). The model discriminated patients in three comparable groups: 34% with a very high (>90%) or low (<10%) probability of severe fibrosis, 33% with a probability ranging from 75% to 90%, and 33% with an uncertain diagnosis (i.e., a probability ranging from 10% to 74%). The observed frequency of severe fibrosis/cirrhosis was within the predefined ranges.

CONCLUSION

The model can correctly identify 67% of patients with a high (>75%) or low (<10%) probability of cirrhosis, leaving only 33% of the patients still requiring liver biopsy.

A pilot approach for quantitative assessment of liver fibrosis using ultrasound: preliminary results in 79 cases

BACKGROUND/AIMS

Ultrasound is noninvasive and useful to evaluate liver disease despite its operator dependency. This pilot study was conducted to quantitatively assess liver fibrosis using ultrasound.

METHODS

Fibrosis extraction ratios (FER) (fiber volume/total volume) of ultrasound and histological images of 8 autopsy specimens were compared. We also compared FER of ultrasound images from clinical patients (n=79) with histological fibrosis stages.

RESULTS

In the autopsy study, FER correlation coefficient between histological images and ultrasound images was 0.992. Regarding clinical patients, there was sufficient evidence to indicate differences in the distributions of FER for each fibrosis stage (Kruskal-Wallis test P<0.0001). With FER cut-off to distinguish > or =F2 from F0 and F1 defined as mean plus standard deviation of F0 and F1, sensitivity, specificity, positive predictive value, negative predictive value, and likelihood ratio were 62, 75, 78, 57%, and 2.47, respectively. Regarding HCV cohort (n=44), they were 55, 87, 89, 50%, and 4.14, respectively. Areas under receiver operating characteristic curves were 0.78, 0.79, 0.83 and 0.83 for > or =F1, > or =F2, > or =F3 and =F4, respectively. Regarding HCV cohort, they were 0.74, 0.71, 0.79 for > or =F2, > or =3 and =4, respectively.

CONCLUSIONS

The FER method has great potential for diagnosing liver fibrosis using ultrasound.

Can Doppler sonography grade the severity of hepatitis C-related liver disease?

OBJECTIVE

Many authors have claimed that Doppler sonography indexes are of value in grading and assessing diffuse liver disease. However, there is much controversy regarding the reliability and reproducibility of these techniques. We performed a prospective study to evaluate whether these methods can grade disease in a well-stratified cohort of patients with hepatitis C virus (HCV)-related liver disease.

SUBJECTS AND METHODS

Sixty-five patients with biopsy-proven HCV-related liver disease were recruited, and Doppler sonography was performed by one operator. The patients were classified into one of the following three groups on the basis of the Ishak-modified histologic activity index (HAI) fibrosis (F) and necroinflammatory (NI) scores: mild hepatitis (F < or = 2 and NI < or = 3), moderate or severe hepatitis (3 < or = F < 6 or NI > or = 4), or cirrhosis (F = 6/6). We measured the following Doppler indexes: main hepatic artery peak velocity (Vmax) and resistive index, main portal vein peak velocity (Vmax), and maximal portal vein diameter and circumference that allowed calculation of the portal vein congestive index (portal vein area and portal vein velocity). The ratio of the hepatic artery velocity (Vmax) to the portal vein velocity (Vmax) was also calculated, and the phasicity (triphasic, biphasic, or monophasic) of the hepatic veins of each patient was recorded. We also measured the maximal spleen length longitudinally.

RESULTS

A total of 65 patients with liver disease (mild hepatitis, n = 20; moderate or severe hepatitis, n = 25; cirrhosis, n = 20) with biopsy-proven HCV-related liver disease were studied. Optimal hepatic arterial traces were obtained in only 30 patients and portal vein circumference in 18 patients. No significant differences were observed in the Doppler indexes with increasing severity of liver disease. Five (29%) of 17 patients with mild hepatitis had an abnormal hepatic vein trace (i.e., biphasic or monophasic) compared with 11 (55%) of 20 patients with moderate or severe hepatitis and 12 (60%) of 20 patients with cirrhosis. The only index to show a significant intergroup difference was splenic length (analysis of variance, p < 0.001), but there was still overlap between the groups.

CONCLUSION

Doppler-derived indexes, which have previously been recommended for the assessment of severity in chronic liver disease, are difficult to reproduce reliably and therefore have a limited clinical role in the noninvasive assessment of hepatic fibrosis or inflammation.

Liver fibrosis

Liver fibrosis is the excessive accumulation of extracellular matrix proteins including collagen that occurs in most types of chronic liver diseases. Advanced liver fibrosis results in cirrhosis, liver failure, and portal hypertension and often requires liver transplantation. Our knowledge of the cellular and molecular mechanisms of liver fibrosis has greatly advanced. Activated hepatic stellate cells, portal fibroblasts, and myofibroblasts of bone marrow origin have been identified as major collagen-producing cells in the injured liver. These cells are activated by fibrogenic cytokines such as TGF-beta1, angiotensin II, and leptin. Reversibility of advanced liver fibrosis in patients has been recently documented, which has stimulated researchers to develop antifibrotic drugs. Emerging antifibrotic therapies are aimed at inhibiting the accumulation of fibrogenic cells and/or preventing the deposition of extracellular matrix proteins. Although many therapeutic interventions are effective in experimental models of liver fibrosis, their efficacy and safety in humans is unknown. This review summarizes recent progress in the study of the pathogenesis and diagnosis of liver fibrosis and discusses current antifibrotic strategies.

Liver fibrosis

Liver fibrosis is the excessive accumulation of extracellular matrix proteins including collagen that occurs in most types of chronic liver diseases. Advanced liver fibrosis results in cirrhosis, liver failure, and portal hypertension and often requires liver transplantation. Our knowledge of the cellular and molecular mechanisms of liver fibrosis has greatly advanced. Activated hepatic stellate cells, portal fibroblasts, and myofibroblasts of bone marrow origin have been identified as major collagen-producing cells in the injured liver. These cells are activated by fibrogenic cytokines such as TGF-beta1, angiotensin II, and leptin. Reversibility of advanced liver fibrosis in patients has been recently documented, which has stimulated researchers to develop antifibrotic drugs. Emerging antifibrotic therapies are aimed at inhibiting the accumulation of fibrogenic cells and/or preventing the deposition of extracellular matrix proteins. Although many therapeutic interventions are effective in experimental models of liver fibrosis, their efficacy and safety in humans is unknown. This review summarizes recent progress in the study of the pathogenesis and diagnosis of liver fibrosis and discusses current antifibrotic strategies.

Liver fibrosis

Liver fibrosis is the excessive accumulation of extracellular matrix proteins including collagen that occurs in most types of chronic liver diseases. Advanced liver fibrosis results in cirrhosis, liver failure, and portal hypertension and often requires liver transplantation. Our knowledge of the cellular and molecular mechanisms of liver fibrosis has greatly advanced. Activated hepatic stellate cells, portal fibroblasts, and myofibroblasts of bone marrow origin have been identified as major collagen-producing cells in the injured liver. These cells are activated by fibrogenic cytokines such as TGF-beta1, angiotensin II, and leptin. Reversibility of advanced liver fibrosis in patients has been recently documented, which has stimulated researchers to develop antifibrotic drugs. Emerging antifibrotic therapies are aimed at inhibiting the accumulation of fibrogenic cells and/or preventing the deposition of extracellular matrix proteins. Although many therapeutic interventions are effective in experimental models of liver fibrosis, their efficacy and safety in humans is unknown. This review summarizes recent progress in the study of the pathogenesis and diagnosis of liver fibrosis and discusses current antifibrotic strategies.

Value of Doppler sonography in assessing the progression of chronic viral hepatitis and in the diagnosis and grading of cirrhosis

OBJECTIVE

The purpose of this study was to evaluate the value of Doppler sonography in assessing the progression of chronic viral hepatitis and in the diagnosis and grading of cirrhosis.

METHODS

Abdominal sonographic and liver Doppler studies were performed in 3 groups: 36 patients with chronic viral hepatitis, 63 patients with cirrhosis, and 30 control subjects with no evidence of liver disease. A series of Doppler indices of hepatic vascularity, including portal vein velocity, portal vein pulsatility score, flow volume of the portal vein, resistive and pulsatility indices of the hepatic artery, modified hepatic index, hepatic vascular index, waveform of the hepatic vein, and focal acceleration of flow, were measured and correlated with liver and spleen size, portal and splenic vein diameter, and presence of ascites and collateral vessels. These indices were compared across the 3 study groups and within the patient groups with respect to presence of inflammation, fibrosis, and steatosis, as determined by histologic evaluation.

RESULTS

The most useful indices were portal vein velocity, the modified hepatic index, and nontriphasic flow in the hepatic vein, which were helpful in distinguishing patients from control subjects. Hepatic vascular and modified hepatic indices were useful for differential diagnosis of cirrhosis and chronic viral hepatitis. However, all measurements were limited in their ability to determine the severity of chronic hepatitis.

CONCLUSIONS

Doppler sonography is sensitive to hemodynamic alterations resulting from inflammation and fibrosis, and if sonography is the study of choice to follow the progression of hepatitis, it will not be adequate without Doppler imaging. Doppler sonography has high diagnostic accuracy in cirrhosis despite some false-positive conditions. However, it has a limited role in clinical grading.

Impairment of change in diameter of the hepatic portion of the inferior vena cava: a sonographic sign of liver fibrosis or cirrhosis

OBJECTIVE

We propose a new sonographic technique for detecting parenchymal stiffness of the liver. This technique measures the physiologic change in the diameter of the hepatic inferior vena cava (IVC). The hepatic portion of the IVC is extensively attached to the hepatic parenchyma so that changes in diameter of the venous lumen could not occur without changes in the shape of the surrounding parenchyma. Therefore, increased parenchymal stiffness due to cirrhosis or fibrosis may result in an impaired change in venous diameter.

METHODS

Thirty patients with histologically proven cirrhosis and 30 patients with normal livers were examined. A commercial ultrasound system was used in conjunction with a convex probe at a center frequency of 4.0 MHz. The major axis of the IVC was measured during normal breathing. The patients were then requested to take a deep breath to produce negative intrathoracic pressure, and the same measurement as that during normal breathing was repeated immediately.

RESULTS

In the normal liver group, the maximal diameter of the vena cava was 2.35 +/- 0.34 cm (mean +/- SD), and this was reduced by 1.30 +/- 0.67 cm (range, 0.4-2.85 cm) during deep inspiration. In the cirrhotic patient group, the maximal diameter was 1.74 +/- 0.35 cm, and this was reduced by 0.03 +/- 0.09 cm (range, 0.0-0.4 cm) (P < .0001).

CONCLUSIONS

The physiologic change in the diameter of the hepatic portion of the IVC enhanced by deep respiration may reflect the stiffness of hepatic parenchyma.

Clinical characteristics of portal hemodynamics in alcoholic liver cirrhosis

BACKGROUND

Low incidence of reversal blood flow at the portal vein has been reported by measurement in larger and extrahepatic blood vessels but not in intrahepatic blood vessels in patients with liver cirrhosis. Moreover, there is little information regarding the incidence of reversal blood on the basis of the cause of liver cirrhosis. The aim of this study was to measure the reversal blood flow in the portal vein including intrahepatic branches in patients with alcoholic and viral cirrhosis.

METHODS

The blood flow in the portal vein and existence of portosystemic shunt were studied in 52 and 27 patients with alcoholic and viral cirrhosis, respectively, by Doppler ultrasonography. The parameters of liver function test and the prevalence of ascites and esophageal varices were compared between patients with and without reversal blood flow.

RESULTS

Reversal blood flow at the portal vein was found only in patients with only alcoholic cirrhosis (17 of 52 patients) but not in any patients with viral cirrhosis (0 of 27 patients; p < 0.05). The incidence of portosystemic ascites and red color of esophageal varices was also higher in patients with alcoholic cirrhosis with reversal blood flow in the portal vein compared with patients without reversal blood flow (p < 0.05).

CONCLUSIONS

Reversal blood flow in the portal vein is a characteristic feature of alcoholic cirrhosis. The presence of reversal blood flow indicates severe liver diseases, and this feature may have prognostic importance for patients with alcoholic cirrhosis.

Liver fibrosis

Liver fibrosis is the excessive accumulation of extracellular matrix proteins including collagen that occurs in most types of chronic liver diseases. Advanced liver fibrosis results in cirrhosis, liver failure, and portal hypertension and often requires liver transplantation. Our knowledge of the cellular and molecular mechanisms of liver fibrosis has greatly advanced. Activated hepatic stellate cells, portal fibroblasts, and myofibroblasts of bone marrow origin have been identified as major collagen-producing cells in the injured liver. These cells are activated by fibrogenic cytokines such as TGF-beta1, angiotensin II, and leptin. Reversibility of advanced liver fibrosis in patients has been recently documented, which has stimulated researchers to develop antifibrotic drugs. Emerging antifibrotic therapies are aimed at inhibiting the accumulation of fibrogenic cells and/or preventing the deposition of extracellular matrix proteins. Although many therapeutic interventions are effective in experimental models of liver fibrosis, their efficacy and safety in humans is unknown. This review summarizes recent progress in the study of the pathogenesis and diagnosis of liver fibrosis and discusses current antifibrotic strategies.

Sampling variability of liver fibrosis in chronic hepatitis C

Fibrosis is a common endpoint of clinical trials in chronic hepatitis C, and liver biopsy remains the gold standard for fibrosis evaluation. However, variability in the distribution of fibrosis within the liver is a potential limitation. Our aim was to assess the heterogeneity of liver fibrosis and its influence on the accuracy of assessment of fibrosis with liver biopsy. Surgical samples of livers from patients with chronic hepatitis C were studied. Measurement of fibrosis was performed on the whole section by using both image analysis and METAVIR score (reference value). From the digitized image of the whole section, virtual biopsy specimens of increasing length were produced. Fibrosis was assessed independently on each individual virtual biopsy specimen. Results were compared with the reference value according to the length of the biopsy specimen. By using image analysis, the coefficient of variation of fibrosis measurement with 15-mm long biopsy specimens was 55%; and for biopsy specimens of 25-mm length it was 45%. By using the METAVIR scoring system, 65% of biopsies 15 mm in length were categorized correctly according to the reference value. This increased to 75% for a 25-mm liver biopsy specimen without any substantial benefit for longer biopsy specimens. Sampling variability of fibrosis is a significant limitation in the assessment of fibrosis with liver biopsy. In conclusion, this study suggests that a length of at least 25 mm is necessary to evaluate fibrosis accurately with a semiquantitative score. Sampling variability becomes a major limitation when using more accurate methods such as automated image analysis.