Paediatric chronic liver diseases: how to investigate and follow up? Role of imaging in the diagnosis of fibrosis

Fontan-Associated Liver Disease: A Review

Fontan-associated liver disease (FALD) is a chronic complication of the Fontan procedure, a palliative surgery for patients with congenital heart disease that results in a single-ventricle circulation. The success of the Fontan procedure has led to a growing population of post-Fontan patients living well into adulthood. For this population, FALD is a major cause of morbidity and mortality. It encompasses a spectrum of hepatic abnormalities, ranging from mild fibrosis to cirrhosis and hepatocellular carcinoma. The pathophysiology of FALD is multifactorial, involving hemodynamic and inflammatory factors. The diagnosis and monitoring of FALD present many challenges. Conventional noninvasive tests that use liver stiffness as a surrogate marker of fibrosis are unreliable in FALD, where liver stiffness is also a result of congestion due to the Fontan circulation. Even invasive tissue sampling is inconsistent due to the patchy distribution of fibrosis. FALD is also associated with both benign and malignant liver lesions, which may exhibit similar imaging features. There is therefore a need for validated diagnostic and surveillance protocols to address these challenges. The definitive treatment of end-stage FALD is also a subject of controversy. Both isolated heart transplantation and combined heart-liver transplantation have been employed, with the latter becoming increasingly preferred in the US. This article reviews the current literature on the epidemiology, pathophysiology, diagnosis, and management of FALD, and highlights knowledge gaps that require further research.

Comparison of Fibroscan, Shear Wave Elastography, and Shear Wave Dispersion Measurements in Evaluating Fibrosis and Necroinflammation in Patients Who Underwent Liver Biopsy

OBJECTIVE

Our aim was to predict these stages of hepatic fibrosis and necroinflammation using measurements from two-dimensional shear wave elastography (2D-SWE), transient elastography (Fibroscan, TE), and shear wave dispersion (SWD).

MATERIALS AND METHODS

In this prospectively designed study, chronic liver patients with nonspecific etiology whose biopsy was performed for up to 1 week were included. Two-dimensional SWE, SWD, and TE measurements were performed. The METAVIR and F-ISHAK classification was used for histopathological evaluation.

RESULTS

Two-dimensional SWE and TE were considered significant for detecting hepatic fibrosis. In distinguishing ≥F2, for 2D-SWE, area under the receiver operating characteristics (AUROC) was 0.86 (confidence interval [CI], 0.75-0.96) for the cutoff value of 8.05 kPa ( P = 0.003); for TE, AUROC was 0.79 (CI, 0.65-0.94) for the cutoff value of 10.4 kPa ( P < 0.001). No significance was found for TE in distinguishing ≥F3 ( P = 0.132). However, for 2D-SWE, a cutoff value of 10.45 kPa ( P < 0.001), with AUROC = 0.87 (CI, 0.78-0.97) was determined for ≥F3. Shear wave dispersion was able to determine the presence of necroinflammation ( P = 0.016) and a cutoff value of 15.25 (meter/second)/kiloHertz ([m/s]/kHz) ( P = 0.006) and AUROC of 0.71 (CI, 0.57-0.85) were calculated for distinguishing ≥A2. In addition, a cutoff value of 17.25 (m/s)/kHz ( P = 0.023) and AUROC = 0.72 (CI, 0.51-0.93) were found to detect severe necroinflammation. The cutoff value for SWD was 15.25 (m/s)/kHz ( P = 0.013) for detecting ≥A2 in the reversible stage of fibrosis (F0, F1, and F2), and AUROC = 0.72 (CI, 0.56-0.88).

CONCLUSIONS

Two-dimensional SWE and TE measurements were significant in detecting the irreversible stage and the stage that should be treated in hepatic fibrosis noninvasively. Shear wave dispersion measurements were significant in detecting necroinflammation noninvasively.

Real-Time Shear Wave Elastography for Determining the Ideal Site of Liver Biopsy in Diffuse Liver Disease

Objectives  The objective of the study was to identify accurate site of liver biopsy under ultrasound and elastography guidance and compare the shear wave elastography (SWE) and transient elastography (TE) diagnostic accuracy with histopathological correlation. Methods  This was a prospective single-center study where patients scheduled for nonfocal liver biopsy were divided into two groups (group U: ultrasound; group E elastography) by sequential nonrandom selection of patients. Elastography was performed before the biopsy and biopsies from the maximum stiffness segment were taken. Results  There was no significant difference of intersegmental liver stiffness with mean velocity; however, biopsy segment velocities show significant difference with mean liver stiffness suggestive of heterogenous distribution of fibrosis. The rho ( r ; Spearman's correlation) value between biopsy segments and mean velocities shows excellent correlation. The diagnostic performance of TE was good for fibrosis stages F2, F3, and F4, while SWE was fair for the diagnosis of fibrosis stages F1 and F2 and fairly equal for the diagnosis stages F2 and F3. Area under the curve (AUC) values in differentiating mild (F1) or no fibrosis from significant fibrosis (≥F2) were 95.5 with cutoff value of at least 1.94 m/s. Conclusions  The diagnostic performance of SWE is comparable with TE in liver fibrosis staging and monitoring. Fibrosis is heterogeneously distributed in different segments of the right lobe liver. Therefore, elastography at the time of biopsy may help in defining the accurate site for biopsy and improve histopathological yield in detecting liver fibrosis in patients with chronic liver disease. Advances in Knowledge  Elastography-guided biopsy is helpful to determine the ideal site of biopsy.

Liver cirrhosis in children - the role of imaging in the diagnostic pathway

Liver cirrhosis in children is a rare disease with multifactorial causes that are distinct from those in adults. Underlying reasons include cholestatic, viral, autoimmune, hereditary, metabolic and cardiac disorders. Early detection of fibrosis is important as clinical stabilization or even reversal of fibrosis can be achieved in some disorders with adequate treatment. This article focuses on the longitudinal evaluation of children with chronic liver disease with noninvasive imaging tools, which play an important role in detecting cirrhosis, defining underlying causes, grading fibrosis and monitoring patients during follow-up. Ultrasound is the primary imaging modality and it is used in a multiparametric fashion. Magnetic resonance imaging and computed tomography are usually applied second line for refined tissue characterization, clarification of nodular lesions and full delineation of abdominal vessels, including portosystemic communications.

Fontan-associated liver disease: Diagnosis, surveillance, and management

The Fontan operation is a lifesaving procedure for patients with functional single-ventricle congenital heart disease, where hypoplastic left heart syndrome is the most frequent anomaly. Hemodynamic changes following Fontan circulation creation are now increasingly recognized to cause multiorgan affection, where the development of a chronic liver disease, Fontan-associated liver disease (FALD), is one of the most important morbidities. Virtually, all patients with a Fontan circulation develop liver congestion, resulting in fibrosis and cirrhosis, and most patients experience childhood onset. FALD is a distinctive type of congestive hepatopathy, and its pathogenesis is thought to be a multifactorial process driven by increased nonpulsatile central venous pressure and decreased cardiac output, both of which are inherent in the Fontan circulation. In the advanced stage of liver injury, complications of portal hypertension often occur, and there is a risk of developing secondary liver cancer, reported at young age. However, FALD develops with few clinical symptoms, a surprisingly variable degree of severity in liver disease, and with little relation to poor cardiac function. The disease mechanisms and modifying factors of its development are still not fully understood. As one of the more important noncardiac complications of the Fontan circulation, FALD needs to be diagnosed in a timely manner with a structured monitoring scheme of disease development, early detection of malignancy, and determination of the optimal time point for transplantation. There is also a clear need for consensus on the best surveillance strategy for FALD. In this regard, imaging plays an important role together with clinical scoring systems, biochemical workups, and histology. Patients operated on with a Fontan circulation are generally followed up in cardiology units. Ultimately, the resulting multiorgan affection requires a multidisciplinary team of healthcare personnel to address the different organ complications. This article discusses the current concepts, diagnosis, and management of FALD, with special emphasis on the role of different imaging techniques in the diagnosis and monitoring of disease progression, as well as current recommendations for liver disease surveillance.

Surgical management of extrahepatic portal vein obstruction in children: advantages of MesoRex shunt compared with distal splenorenal shunt

PURPOSE

To review surgical management of extrahepatic portal vein obstruction (EHPVO) at Red Cross War Memorial Children's Hospital and compare MesoRex shunt (MRS) with distal splenorenal shunt (DSRS).

METHODS

This is a single-centre retrospective review documenting pre- and post-operative data in 21 children. Twenty-two shunts were performed, 15 MRS and 7 DSRS, over an 18-year period. Patients were followed up for a mean of 11 years (range 2-18). Data analysis included demographics, albumin, prothrombin time (PT), partial thromboplastin time (PTT), International normalised ratio (INR), fibrinogen, total bilirubin, liver enzymes and platelets before the operation and 2 years after shunt surgery.

RESULTS

One MRS thrombosed immediately post-surgery and the child was salvaged with DSRS. Variceal bleeding was controlled in both groups. Significant improvements were seen amongst MRS cohort in serum albumin, PT, PTT, and platelets and there was a mild improvement in serum fibrinogen. The DSRS cohort showed only a significant improvement in the platelet count. Neonatal umbilic vein catheterization (UVC) was a major risk for Rex vein obliteration.

CONCLUSION

In EHPVO, MRS is superior to DSRS and improves liver synthetic function. DSRS does control variceal bleeding but should only be considered when MRS is not technically feasible or as a salvage procedure when MRS fails.

Efficacy and Safety of Endoscopic Primary Prophylaxis of Bleeding in Children With High-Risk Gastroesophageal Varices

OBJECTIVES

Primary prophylaxis of bleeding is debated in children with gastroesophageal varices; one of the reasons is the limited number of studies concerning its efficacy and safety. We report our experience with endoscopic primary prophylaxis.

METHODS

From 2006 to 2019, 145 children (median age, 3.5 years; cirrhosis, n = 116) with high-risk gastroesophageal varices underwent primary prophylaxis (banding, n = 114; sclerotherapy n = 31, primarily in smaller children).

RESULTS

We observed the eradication of varices in 93% of children after a mean of 6 months, at least one recurrence of varices in 45% after eradication, and gastrointestinal bleeding in 17% of children. Irrespective of the cause of portal hypertension, grade 3 esophageal varices, presence of gastric varices along the cardia and a lower composite score of endoscopic severity were associated with a worse probability of eradication, a longer time to eradication and a lower risk of a first recurrence and of bleeding following the procedure, respectively. Ten-year probabilities of overall survival and of bleeding-free survival were 95% and 75%, respectively.

CONCLUSIONS

Endoscopic primary prophylaxis of variceal bleeding is reasonably effective and safe in children with high-risk gastroesophageal varices. Worse results are observed in children with more advanced endoscopic features. This pleads for endoscopic screening in children with portal hypertension and early detection of varices warranting primary prophylaxis.

[Postoperative Imaging Findings of Biliary Atresia]

The Kasai portoenterostomy is the first-line treatment for the restoration of the flow of bile to the small intestine in patients with biliary atresia. Various complications can occur after Kasai portoenterostomy, including ascending cholangitis, biliary cirrhosis, and portal hypertension. Of these potential complications, ascending cholangitis in the most common. In cases of patients having uncontrolled complications due to progressive liver cirrhosis, portal hypertension, or progressive hyperbilirubinemia, liver transplantation is the indicated as treatment plan. Lifelong follow-up, particularly involving imaging studies, is important for the identification of various complications arising from biliary atresia after Kasai portoenterostomy. Additionally, imaging studies play a crucial role in the evaluation of potential liver donors and recipients. US is a key imaging modality utilized in the management of patients who undergo Kasai portoenterostomy, while CT and MRI are imperative to obtaining an accurate diagnosis.

Technical feasibility and correlations between shear-wave elastography and histology in kidney fibrosis in children

BACKGROUND

Ultrasound elastography has been suggested for assessing organ fibrosis.

OBJECTIVE

To study the feasibility of shear-wave elastography in children with kidney disease and the correlation between elasticity and kidney fibrosis in order to reduce the indications for kidney biopsy and its complications.

MATERIALS AND METHODS

Four operators measured kidney elasticity in children with kidney diseases or transplants, all of whom also had a renal biopsy. We assessed the feasibility and the intraobserver variability of the elasticity measurements for each probe used and each kidney explored. Then we tested the correlation between elasticity measurements and the presence of fibrosis.

RESULTS

Overall, we analyzed 95 children and adolescents, 31 of whom had renal transplant. Measurements with the convex probe were possible in 100% of cases. Linear probe analysis was only possible for 20% of native kidneys and 50% of transplants. Intraobserver variabilities ranged from moderate to high, depending on the probe and kidney studied. Elasticity was higher with the linear probe than with the convex probe (P<0.001 for left kidney and P=0.03 for right kidney). Measurements did not differ from one kidney to another in the same child. Elasticity and fibrosis were both higher in transplant patients (P=0.02 with convex probe; P=0.01 with linear probe; P=0.04 overall). There was no correlation between elasticity and fibrosis.

CONCLUSION

Of the devices used in this work, kidney elastography was more accurately analyzed with a convex probe. Our study did not identify any correlation between elasticity and kidney fibrosis.

Surveillance of Fontan-associated liver disease: current standards and a proposal from the European Society of Paediatric Radiology Abdominal Task Force

Since Francis Fontan first introduced the eponymous technique, the Fontan procedure, this type of surgical palliation has allowed thousands of children affected by specific heart malformations to reach adulthood. Nevertheless, abdominal, thoracic, lymphatic and neurologic complications are the price that is paid by these patients. Our review focuses on Fontan-associated liver disease; the purpose is to summarize the current understanding of its physiopathology, the aim of follow-up and the specific radiologic follow-up performed in Europe. Finally, we as members of the Abdominal Task Force of the European Society of Paediatric Radiology propose a consensus-based imaging follow-up algorithm.

pCLIF-SOFA is a reliable outcome prognostication score of critically ill children with cirrhosis: an ESPNIC multicentre study

Background and aims

Data on outcome of critically ill children with cirrhosis are scarce. We aimed to evaluate the prognostic accuracy of sequential organs scoring systems in children with cirrhosis admitted to Paediatric Intensive Care Units (PICU).

Methods

We performed a multicentre retrospective analysis of children with cirrhosis admitted into four European PICUs between 2011 and 2016. Investigators were members of the ESPNIC liver failure and support working group. Paediatric End-Stage Liver Disease (PELD) and paediatric chronic liver failure sequential organ failure assessment score (pCLIF-SOFA) diagnostic accuracy for 28- and 60-day liver transplantation, 28-day mortality and 60-day composite outcome (ie. death or liver transplantation) were tested.

Results

One-hundred-and-thirty children were included. The main causes for PICU admission were acute-on-chronic liver failure (ACLF), gastrointestinal bleeding and sepsis. Twenty-nine percent died and 22.3% were transplanted by day-60 after PICU admission. On multivariable analysis, pCLIF-SOFA was the only predictor of mortality at day-28 and of composite outcome. Both pCLIF-SOFA and ACLF were independently associated with emergent liver transplantation. The pCLIF-SOFA score higher than 9 well predicted a 28-day mortality with a sensitivity of 87.8% and a specificity of 77.3%. A pCLIF-SOFA score higher than 7 was independently associated with liver transplantation on day-60. Stage 3 AKI assessed with KDIGO classification was significantly associated with 28-day mortality.

Conclusions

Half of critically ill cirrhotic children admitted to PICU either died or were transplanted within the initial 28-day period. On admission pCLIF-SOFA score accurately identify patients transplanted at day-28 and day-60 to those alive without LT and is associated with 28-day mortality and composite outcome at day-60.

Accuracy of real-time shear wave elastography in staging hepatic fibrosis: a meta-analysis

Background

Chronic liver disease (CLD) is an important cause of morbidity and mortality and can lead to hepatic fibrosis. This study was conducted to evaluate the diagnostic value of real-time shear wave elastography (SWE) in the assessment of hepatic fibrosis.

Methods

A systematic search of databases was performed for publications on SWE during the period between 2010 and 2017. The identified studies were analyzed using Meta-disc 1.4 software to integrate and analyze the data.

Results

Eleven studies comprising 1560 patients were included for analysis. The pooled sensitivity, specificity and diagnostic odds ratio were 0.85 (95% CI: 0.82–0.87), 0.79 (95% CI: 0.76–0.82) and 30.81 (95% CI: 16.55–57.34), respectively for patients with a Metavir-score of ≥ F2; 0.87 (95% CI: 0.84–0.91), 0.84 (95% CI: 0.82–0.87), 41.45 (95% CI:18.25–94.45), respectively for patients with ≥ F3; 0.88(95% CI: 0.83–0.91), 0.91 (95% CI: 0.89–0.92), 67.18 (95% CI:30.02–150.31), respectively for patients with ≥ F4. The areas under the receiver operating characteristic curve of the three groups were 0.9147, 0.9223 and 0.9520, respectively.

Conclusions

Our work demonstrates that SWE is highly accurate for detecting and staging hepatic fibrosis.

Predisposing Conditions to Pediatric Hepatocellular Carcinoma and Association With Outcomes: Single-center Experience

OBJECTIVES

Hepatocellular carcinoma (HCC) has been linked to chronic viral or metabolic liver disease and other conditions. The characteristics of children with HCC have not been fully elucidated and outcomes in children with predisposing liver disease are not well defined.

METHODS

Patients ≤21 years old with HCC managed at our institution and through external consultation between 1996 and 2016 were included. Demographics, clinical history, and pathology were tabulated. Fisher exact test and Wilcoxon test were employed for subgroup comparison, and survival differences were evaluated by Kaplan-Meier method.

RESULTS

Sixty-one cases of HCC were identified. Seven of 16 patients (44%) at our institution and 18 of 45 consult patients (40%) had a predisposing condition: cryptogenic cirrhosis/steatosis (9), genetic (7), biliary pathology (4), viral hepatitis (1), and other (4). Thirteen of 27 patients with de novo HCC had fibrolamellar HCC. Clinical characteristics were grouped by presence or absence of predisposing conditions: age at diagnosis (7.2 vs 10.2 years, P < 0.05), metastatic disease at presentation (15% vs 44%, P = n.s), and tumor size >4 cm (20% vs 100%, P < 0.05). In patients treated at our institution, 5 of 7 with predisposing conditions received liver transplant and achieved complete remission, whereas only 3 of 9 patients with de novo HCC received curative surgery and this group had decreased median overall survival (P < 0.05).

CONCLUSIONS

The majority of children with HCC did not have predisposing liver or associated disease. These patients were diagnosed later with more advanced stage disease and had significantly decreased overall survival.

Predicting gastroesophageal varices through spleen magnetic resonance elastography in pediatric liver fibrosis

BACKGROUND

A recent retrospective study confirmed that hepatic stiffness and splenic stiffness measured with magnetic resonance elastography (MRE) are strongly associated with the presence of esophageal varices. In addition, strong correlations have been reported between splenic stiffness values measured with MRE and hepatic venous pressure gradients in animal models. However, most studies have been conducted on adult populations, and previous pediatric MRE studies have only demonstrated the feasibility of MRE in pediatric populations, while the actual clinical application of spleen MRE has been limited.

AIM

To assess the utility of splenic stiffness measurements by MRE to predict gastroesophageal varices in children.

METHODS

We retrospectively reviewed abdominal MRE images taken on a 3T system in pediatric patients. Patients who had undergone Kasai operations for biliary atresia were selected for the Kasai group, and patients with normal livers and spleens were selected for the control group. Two-dimensional spin-echo echo-planar MRE acquisition centered on the liver, with a pneumatic driver at 60 Hz and a low amplitude, was performed to obtain hepatic and splenic stiffness values. Laboratory results for aspartate aminotransferase to platelet ratio index (APRI) were evaluated within six months of MRE, and the normalized spleen size ratio was determined with the upper normal size limit. All Kasai group patients underwent gastroesophageal endoscopy during routine follow-up. The Mann-Whitney U test, Kendall's tau b correlation and diagnostic performance analysis using the area under the curve (AUC) were performed for statistical analysis.

RESULTS

The median spleen MRE value was 5.5 kPa in the control group (n = 9, age 9-18 years, range 4.7-6.4 kPa) and 8.6 kPa in the Kasai group (n = 22, age 4-18 years, range 5.0-17.8 kPa). In the Kasai group, the APRI, spleen size ratio and spleen MRE values were higher in patients with portal hypertension (n = 11) than in patients without (n = 11) (all P < 0.001) and in patients with gastroesophageal varices (n = 6) than in patients without (n = 16) (all P < 0.05), even though their liver MRE values were not different. The APRI (τ = 0.477, P = 0.007), spleen size ratio (τ = 0.401, P = 0.024) and spleen MRE values (τ = 0.426, P = 0.016) also correlated with varices grades. The AUC in predicting gastroesophageal varices was 0.844 at a cut-off of 0.65 (100% sensitivity and 75% specificity) for the APRI, and 0.844 at a cut-off of 9.9 kPa (83.3% sensitivity and 81.3% specificity) for spleen MRE values.

CONCLUSION

At a cut-off of 9.9 kPa, spleen MRE values predicted gastroesophageal varices as well as the APRI and spleen size ratio in biliary atresia patients after the Kasai operation. However, liver MRE values were not useful for this purpose.

Abdominal imaging findings in adult patients with Fontan circulation

Abstract

The Fontan procedures, designed to treat paediatric patients with functional single ventricles, have markedly improved the patient’s survival into adulthood. The physiology of the Fontan circuit inevitably increases systemic venous pressure, which may lead to multi-system organ failure in the long-term follow-up. Fontan-associated liver disease (FALD) can progress to liver cirrhosis with signs of portal hypertension. Focal nodular hyperplasia-like nodules commonly develop in FALD. Imaging surveillance is often performed to monitor the progression of FALD and to detect hepatocellular carcinoma, which infrequently develops in FALD. Other abdominal abnormalities in post-Fontan patients include protein losing enteropathy and pheochromocytoma/paraganglioma. Given that these abdominal abnormalities are critical for patient management, it is important for radiologists to become familiar with the abdominal abnormalities that are common in post-Fontan patients on cross-sectional imaging.

Teaching points

• Fontan procedure for functional single ventricle has improved patient survival into adulthood.

• Radiologists should be familiar with unique imaging findings of Fontan-associated liver disease.

• Focal nodular hyperplasia-like nodules commonly develop in Fontan-associated liver disease.

• Hepatocellular carcinoma, protein-losing enteropathy, pheochromocytoma/paraganglioma may develop.

Electronic supplementary material

The online version of this article (10.1007/s13244-018-0609-2) contains supplementary material, which is available to authorized users.

Hepatic Portocholecystostomy: 97 Cases From a Single Institution

OBJECTIVES

Approximately 20% of cases of biliary atresia do not involve the gallbladder, the cystic duct, and the common bile duct. In these cases, a hepatoportocholecystostomy (HPC) may be performed instead of the classical hepatoportoenterostomy (HPE).

METHODS

We reviewed our cohort to investigate the efficacy of HPC and the associated surgical complications and clinical problems.

RESULTS

From 1984 to 2009, 97 patients underwent HPC in our institution. In the first 6 months of the postoperative period no patient presented with bacterial cholangitis. Nine patients had bile leakage, and 1 patient had a gallbladder obstruction. For these 10 patients, HPC was modified in HPE. Jaundice clearance was maintained after HPE, but 4 of the patients presented 1 or more cholangitis episodes. After 6 months, there were no cases of cholangitis recorded, 2 patients presented bile leakage and 4 patients experienced gallbladder obstruction. After 5 years of follow-up, 46% of the patients were jaundice free with their native liver and 29.4% were transplanted.

CONCLUSIONS

In patients with biliary atresia with patent extrahepatic bile ducts, hepatoportocholecystomy is a good surgical technique that can prevent cholangitis. These results are counterbalanced by specific surgical complications that need to be known and looked for in the postoperative period.

Accurate measurements of liver stiffness using shear wave elastography in children and young adults and the role of the stability index

Purpose

The purpose of this study was to evaluate the usefulness of the stability index (SI) in liver stiffness measurements using shear wave elastography (SWE) in children.

Methods

A total of 29 children and young adults (mean age, 16.1 years; range, 8 to 28 years; 11 boys and 18 girls) who underwent liver stiffness measurements using SWE under free-breathing and breath-holding conditions were included in our study. Ten SWE measurements were acquired in each of four groups: free-breathing and breath-holding, and with and without using the SI. The failure rate of acquisition of SI values over 90% was calculated in each group. To evaluate variability in the SWE measurements, the standard deviation, coefficient of variation, and percentage of unreliable measurements were compared. Intraobserver agreement and the optimal minimal number of measurements were calculated using intraclass correlation coefficients.

Results

A failure to acquire SI values over 90% was observed in 17% of the scans in the free-breathing group and in 7% of the scans in the breath-holding group. In both groups, utilizing the SI led to a significantly lower standard deviation and coefficient of variation. When using the SI, the percentage of unreliable measurements decreased from 16.7% to 8.3% in the free-breathing group and 14.8% to 0% in the breath-holding group. With the use of the SI, intraobserver agreement increased and the optimal minimal number of repeated measurements decreased in both the free-breathing and breath-holding groups.

Conclusion

Utilization of the SI in the measurement of liver SWE in children reduced measurement variability and increased reliability in both free-breathing and breath-holding conditions.

Repeatability of MR Elastography of Liver: A Meta-Analysis

Purpose To perform a meta-analysis to generate an estimate of the repeatability coefficient (RC) for magnetic resonance (MR) elastography of the liver. Materials and Methods A systematic search of databases was performed for publications on MR elastography during the 10-year period between 2006 and 2015. The identified studies were screened independently and were verified reciprocally by all authors. Two reviewers independently determined the percentage RC and effective sample size from each article. A forest plot was constructed of the percentage RC estimates from the 12 studies. Bootstrap 95% confidence intervals (CIs) were constructed for the summary percentage RCs. Results Twelve studies comprising 274 patients met the eligibility criteria and were included for analysis. A flow diagram of studies included according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was prepared for the inclusion and exclusion criteria. All studies included in the meta-analysis fulfilled four or more of the seven categories of the Quality Assessment of Diagnostic Accuracy Studies (QUADAS)-2. The estimated summary RC was 22% (95% CI: 16.1%, 28.2%). The three main sources for this heterogeneity were the trained versus untrained operator drawing contours to choose regions of interest, the time between two replicate examinations, and, finally, the field strength of the MR imaging unit. The RC estimates tended to be higher for studies that did not use a well-trained operator, those with 1.5-T field strength imaging units, and those with longer time intervals between examinations. Conclusion The meta-analysis results provide the basis for the following draft longitudinal Quantitative Imaging Biomarkers Alliance MR elastography claim: A measured change in hepatic stiffness of 22% or greater, at the same site and with use of the same equipment and acquisition sequence, indicates that a true change in stiffness has occurred with 95% confidence. ^© RSNA, 2017.

Portal hypertension in children: High-risk varices, primary prophylaxis and consequences of bleeding

BACKGROUND & AIMS

Primary prophylaxis of bleeding is debated for children with portal hypertension because of the limited number of studies on its safety and efficacy, the lack of a known endoscopic pattern carrying a high-risk of bleeding for all causes, and the assumption that the mortality of a first bleed is low. We report our experience with these issues.

METHODS

From 1989 to 2014, we managed 1300 children with portal hypertension. Endoscopic features were recorded; high-risk varices were defined as: grade 3 esophageal varices, grade 2 varices with red wale markings, or gastric varices. Two hundred forty-six children bled spontaneously and 182 underwent primary prophylaxis. The results of primary prophylaxis were reviewed as well as bleed-free survival, overall survival and life-threatening complications of bleeding.

RESULTS

High-risk varices were found in 96% of children who bled spontaneously and in 11% of children who did not bleed without primary prophylaxis (p<0.001), regardless of the cause of portal hypertension. Life-threatening complications of bleeding were recorded in 19% of children with cirrhosis and high-risk varices who bled spontaneously. Ten-year probabilities of bleed-free survival after primary prophylaxis in children with high-risk varices were 96% and 72% for non-cirrhotic causes and cirrhosis respectively. Ten-year probabilities of overall survival after primary prophylaxis were 100% and 93% in children with non-cirrhotic causes and cirrhosis respectively.

CONCLUSION

In children with portal hypertension, bleeding is linked to the high-risk endoscopic pattern reported here. Primary prophylaxis of bleeding based on this pattern is fairly effective and safe.

LAY SUMMARY

In children with liver disease, the risk of bleeding from varices in the esophagus is linked to their large size, the presence of congestion on their surface and their expansion into the stomach but not to the child's age nor to the cause of portal hypertension. Prevention of the first bleed in children with high-risk varices can be achieved by surgery or endoscopic treatment, and decreases mortality and morbidity.

Portopulmonary Hypertension in Liver Disease Presenting in Childhood

OBJECTIVE

Portopulmonary hypertension (POPH) is a known complication of cirrhosis in adults, but there is little information on its incidence and outcome in children with liver disease. We report 14 patients with POPH and present a synthesis of the medical literature.

METHODS

Diagnosis of POPH in the 14 patients was based on right-sided heart catheterization displaying mean pulmonary artery pressure (mPAP) >25 mmHg, indexed pulmonary vascular resistances >3 Wood units · m, and pulmonary wedge pressure <15 mmHg. A literature review added 84 patients.

RESULTS

In our unit, POPH was found in 0.5% of the children with portal hypertension, 0.9% of the children with end-stage liver disease awaiting transplantation, and 3 children with congenital portosystemic shunts (CPSSs). Analysis of 98 reported patients, including the 14 presented here, showed the cause of liver disease to be chronic liver disease or portal cavernoma in 76 instances (34 with a history of surgical portosystemic shunt) and CPSS in 22 instances. There was a precession with proven hypoxemia caused by hepatopulmonary syndrome in 6 patients. Median survival was 3 months in 56 untreated patients. An 80% 5-year probability of survival in 42 patients was treated by CPSS closure, pulmonary vasodilators, and/or liver transplantation. Mean pretransplant mPAP was 34 and 49 mmHg in transplant survivors and nonsurvivors, respectively.

CONCLUSIONS

POPH is a rare but extremely severe complication of childhood liver disease. Portosystemic shunts, whether congenital or acquired, likely play an important causative role. Early diagnosis is crucial and requires systematic screening by echocardiography in children at risk.

Normal values of spleen stiffness in healthy children assessed by acoustic radiation force impulse imaging (ARFI): comparison between two ultrasound transducers

BACKGROUND

Portal hypertension, a major complication of hepatic fibrosis, can affect the stiffness of the spleen.

OBJECTIVE

To suggest normal values of spleen stiffness determined by acoustic radiation force impulse imaging in healthy children and to compare measurements using two different US probes.

MATERIALS AND METHODS

In a prospective study, 60 healthy children between 1 day and 14 years of age were assigned to four age groups with 15 children in each. Measurements were performed using two transducers (convex 4C1 and linear 9L4), and 10 measurements were obtained in each child, 5 with each probe.

RESULTS

The mean splenic shear wave velocities were 2.17 m/s (SD 0.35, 95% CI 2.08-2.26) with the 4C1 probe and 2.15 m/s (SD 0.23, 95% CI 2.09-2.21) with the 9L4 probe (not significant).

CONCLUSION

We found normal values for spleen stiffness with no difference in the mean values obtained using two types of US transducers, but with higher variability using a convex compared to a linear transducer.

Cross-vendor validation of liver magnetic resonance elastography

PURPOSE

To evaluate and validate the reproducibility of MR Elastography (MRE)-derived liver stiffness values on two different MR vendor platforms performed on the same subject on the same day.

METHODS

This investigation was approved by the hospital IRB. MRE exams were performed twice in identical fashion in eight volunteers and in five clinical patients on two different 1.5 T MR scanners-once on a Philips MR scanner and immediately afterward in back-to-back fashion on a General Electric MR scanner, or vice versa. All scan parameters were kept identical on the two platforms to the best extent possible. After the MRE magnitude and phase images were obtained, the data were converted into quantitative images displaying the stiffness of the liver parenchyma. Mean liver stiffness values between the two platforms were compared using interclass correlation with a p value <0.05 considered statistically significant.

RESULTS

Interclass correlation coefficient (ICC) value of 0.994 was obtained for 13 subjects with p value <0.001 indicating a significantly positive correlation.

CONCLUSION

As MRE gains in acceptance and as its availability becomes more widespread, it is important to ascertain and confirm that liver stiffness values obtained on different MRE vendor platforms are consistent and reproducible. In this small pilot investigation, we demonstrate that liver stiffness measurement with MRE is reproducible and has very good consistency across two vendor platforms.

Systemic lupus erythematosus complicated with liver cirrhosis in a patient with Papillon-Lefèvre syndrome

We report the first case of a girl who presented with Papillon-Lefèvre syndrome (PLS) and subsequently developed systemic lupus erythematosus and liver cirrhosis. This indicates that autoimmune diseases can be a complication in patients with PLS. Cathepsin C gene mutations were not found in our patient or her mother. Thus, other genetic factors may have been involved in this patient.

Apparent diffusion coefficient value of hepatic fibrosis and inflammation in children with chronic hepatitis

PURPOSE

This study was done to prospectively evaluate the usefulness of apparent diffusion coefficient (ADC) in the diagnosis and grading of hepatic fibrosis and inflammation in children with chronic hepatitis.

MATERIALS AND METHODS

Institutional Review Board approval was obtained. This prospective study was carried out on 50 children with chronic hepatitis (mean age 8.3 ± 3.2 years; 33 boys and 17 girls) and 20 age- and sex-matched healthy control children. The children underwent diffusion-weighted magnetic resonance imaging of the liver. The ADC value of the liver was calculated. The hepatic fibrosis stages (F1-F6) and necroinflammatory activity grades (A1-A4) were calculated. The ADC values of different stages of hepatic fibrosis and grades of necroinflammatory activity were calculated.

RESULTS

The mean ADC value of the liver parenchyma was 1.53 ± 0.17 × 10(-3) mm(2)/s in children with chronic hepatitis and 1.74 ± 0.16 × 10(-3) mm(2)/s in controls. The ADC value was significantly lower in children with hepatic fibrosis compared to controls (p = 0.001). There was a significant difference (p = 0.001) in ADC between mild (F1-F3) and advanced (F4-F6) stages of fibrosis. There was a significant difference (p = 0.004) in ADC between mild (A1-A2) and advanced (A3-A4) grades of necroinflammation. The cut-off ADC values used to differentiate mild from advanced fibrosis and necroinflammation were 1.62 and 1.64 mm(2)/s with an area under the curve of 0.898 and 0.807, respectively. The ADC value negatively correlated with stages of hepatic fibrosis (r = -0.799, p = 0.001) and necroinflammatory activity grade (r = -0.468, p = 0.001).

CONCLUSIONS

We conclude that ADC value is an effective noninvasive parameter for the diagnosis and grading of hepatic fibrosis and inflammation in children with chronic hepatitis.

Paediatric ultrasonography of the liver, hepatobiliary tract and pancreas

In the field of paediatric radiology ultrasonography (US) is the most versatile imaging tool available. Children in general, by virtue of their body composition, are excellent candidates for US exams in whom abdominal anatomy and pathology can be visualised in great detail. The fact that during the US study a clinical history can be obtained strongly adds to the value of the US exam. This does require investment in time and expertise and ideally a paediatric radiologist performing the exam. In this review the role of ultrasonography (US) of the liver, biliary tract and pancreas in children is discussed.

Normal values of liver shear wave velocity in healthy children assessed by acoustic radiation force impulse imaging using a convex probe and a linear probe

Acoustic radiation force impulse (ARFI) is an image-guided ultrasound elastography method that allows quantification of liver stiffness by measurement of shear wave velocity. One purpose of the work described in this article was to determine the normal liver stiffness values of healthy children using ARFI with two different probes, 4 C1 and 9 L4. Another purpose was to evaluate the effects of site of measurement, age, gender and body mass index on liver stiffness values. This prospective study included 60 healthy children (newborn to 14 y) divided into four age groups. One thousand two hundred ARFI measurements were performed, that is, 20 measurements per patient (5 measurements in each lobe, with each probe). Means, standard deviations (SD) and confidence intervals for velocity were calculated for each hepatic lobe and each probe in each age group and for the whole group. Mean shear wave velocity measured in the right lobe was 1.19 ± 0.04 m/s (SD = 0.13) with the 4 C1 transducer and 1.15 ± 0.04 m/s (SD = 0.15) with the 9 L4 transducer. Age had a small effect on shear wave measurements. Body mass index and sex had no significant effects on ARFI values, whereas site of measurement had a significant effect, with lower ARFI values in the right hepatic lobe. ARFI is a non-invasive technique that is feasible to perform in children with both the 4 C1 and 9 L4 probes. The aforementioned velocity values obtained in the right lobe may be used as reference values for normal liver stiffness in children.

Increased hepatic stiffness as consequence of high hepatic afterload in the Fontan circulation: a vascular Doppler and elastography study

Hepatic dysfunction is a recognized complication after Fontan palliation of congenital heart disease. We sought to quantitatively measure hepatic stiffness and vascular Doppler indices using ultrasound (US) and shear wave elastography (SWE) in a Fontan cohort. Subjects were prospectively recruited for echocardiography and real-time hepatic duplex US with SWE for hepatic stiffness (kPa). Doppler peak velocities, velocity time integral, resistive, pulsatility, acceleration indices (RI, PI, AI), and flow volume were measured in celiac artery, superior mesenteric artery, and main portal vein (MPV). A subset underwent cardiac catheterizations with liver biopsy. Correlations were explored between SWE, duplex, hemodynamic, and histopathologic data. In all, 106 subjects were studied including 41 patients with Fontan physiology (age 13.8 ± 6 years, weight 45.4 ± 23 kg) and 65 controls (age 15.0 ± 8.4 years, weight 47.9 ± 22 kg). Patients with Fontan physiology had significantly higher hepatic stiffness (15.6 versus 5.5 kPa, P < 0.0001), higher celiac RI (0.78 versus 0.73, P = 0.04) superior mesenteric artery RI (0.89 versus 0.84, P = 0.005), and celiac PI (1.87 versus 1.6, P = 0.034); while MPV flow volume (287 versus 420 mL/min in controls, P = 0.007) and SMA AI (829 versus 1100, P = 0.002) were lower. Significant correlation was seen for stiffness with ventricular end-diastolic pressure (P = 0.001) and pulmonary artery wedge pressure (P = 0.009). Greater stiffness correlated with greater degrees of histopathologic fibrosis. No significant change was seen in stiffness or other duplex indices with age, gender, time since Fontan, or ventricular morphology.

CONCLUSION

Elevated hepatic afterload in Fontan, manifested by high ventricular end-diastolic pressures and pulmonary arterial wedge pressures, is associated with remarkably increased hepatic stiffness, abnormal vascular flow patterns, and fibrotic histologic changes. The MPV is dilated and carries decreased flow volume, while the celiac and superior mesenteric arterial RI is increased. SWE is feasible in this population and shows promise as a means for predicting disease severity on liver biopsy.

Magnetic resonance elastography of the liver in patients status-post fontan procedure: feasibility and preliminary results

OBJECTIVE

The purpose of this study was to evaluate the feasibility of performing magnetic resonance elastography (MRE) as a screening tool for elevated liver stiffness in patients' status-post Fontan procedure.

BACKGROUND

With greater numbers of Fontan patients surviving far into adulthood, a factor increasingly affecting long-term prognosis is the presence of hepatic congestion and fibrosis. If detected early, steps can be taken to potentially slow or halt the progression of fibrosis. MRE is a relatively new, noninvasive imaging technique, which can quantitatively measure liver stiffness and provide an estimate of the extent of fibrosis.

METHODS

A retrospective study was conducted using MRE to evaluate liver stiffness in patients with a history of Fontan procedure. An MRE was performed in the same session as a clinical cardiac MRI. The liver was interrogated at four slice locations, and a mean liver stiffness value was calculated for each patient using postprocessing software. The medical records were reviewed for demographic and clinical characteristics.

RESULTS

During the time frame of this investigation, 17 MRE exams were performed on 16 patients. All patients had elevated liver stiffness values as defined by MRE standards. The median of the individual mean liver stiffness values was 5.1 kPa (range: 3.4-8.2 kPa). This range of liver stiffness elevation would suggest the presence of mild to severe fibrosis in a patient with standard cardiovascular anatomy. We found a significant trend toward higher liver stiffness values with greater duration of Fontan circulation (rs = 0.55, P = .02).

CONCLUSION

Our preliminary findings suggest that MRE is a feasible method for evaluating the liver in Fontan patients who are undergoing surveillance cardiac MRI. Further investigation with histologic correlation is needed to determine the contributions of hepatic congestion and fibrosis to the liver stiffness in this population.

A pilot study of the characterization of hepatic tissue strain in children with cystic-fibrosis-associated liver disease (CFLD) by acoustic radiation force impulse imaging

BACKGROUND

Progressive fibrotic alterations of liver tissue represent a major complication in children with cystic fibrosis. Correct assessment of cystic-fibrosis-associated liver disease (CFLD) in clinical routine is a challenging issue. Sonographic elastography based on acoustic radiation force impulse imaging (ARFI) is a new noninvasive approach for quantitatively assessing in vivo elasticity of biological tissues in many organs.

OBJECTIVE

To characterize ARFI elastography as a diagnostic tool to assess alteration of liver tissue elasticity related to cystic fibrosis in children.

MATERIALS AND METHODS

ARFI elastography and B-mode US imaging were performed in 36 children with cystic fibrosis. The children's clinical history and laboratory parameters were documented. According to the findings on conventional US, children were assigned to distinct groups indicating severity of hepatic tissue alterations. The relationship between US findings and respective elastography values was assessed. Additionally, differences between ARFI elastography values of each US group were statistically tested.

RESULTS

Children with sonomorphologic characteristics of fibrotic tissue remodeling presented significantly increased values for tissue elasticity. Children with normal B-mode US or discrete signs of hepatic tissue alterations showed a tendency toward increased tissue stiffness indicating early tissue remodeling.

CONCLUSION

Assessment of children with CFLD by means of ARFI elastography yields adequate results when compared to conventional US. For detection of early stages of liver disease with mild fibrotic reactions of hepatic tissue, ARFI elastography might offer diagnostic advantages over conventional US. Thus, liver stiffness measured by means of elastography might represent a valuable biological parameter for evaluation and follow-up of CFLD.

Combined paediatric NAFLD fibrosis index and transient elastography to predict clinically significant fibrosis in children with fatty liver disease

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) encompasses a spectrum of disease from simple steatosis to steatohepatitis, to fibrosis and cirrhosis. The paediatric NAFLD fibrosis index (PNFI) and transient elastography (TE) are potential noninvasive markers for fibrosis. To prospectively evaluate the performance of PNFI and TE in assessing clinically significant fibrosis in children with biopsy-proven NAFLD.

METHODS

Our cohort consisted of 67 consecutive children with biopsy-proven NAFLD. The stage of fibrosis was scored according to the Nonalcoholic Steatohepatitis Clinical Research Network. Fibrosis ≥ 2 was considered clinically significant. PNFI was calculated using age, waist circumference and triglycerides. TE was performed using the Fibroscan apparatus.

RESULTS

Ten patients had fibrosis stage 2-3 and 57 patients had stage 0-1. Both PNFI and TE values were significantly higher in patients with significant fibrosis (P < 0.05). The area under the receiver operating characteristic (ROC) curve for predicting significant fibrosis of PNFI and TE were 0.747 and 1.00 respectively (P = 0.005). The combined use of PNFI and TE could predict the presence or absence of clinically significant fibrosis in 98% of children with NAFLD.

CONCLUSIONS

In children with NAFLD, the combination of PNFI and TE can be used to accurately assess the presence of clinically significant liver fibrosis. This will help to identify patients who should undergo liver biopsy because the confirmation of advanced fibrosis would lead to closer follow-up and screening for cirrhosis-related complications.

Pediatric liver MR elastography

INTRODUCTION

Many chronic pediatric liver disorders are complicated by the development of fibrosis and ultimately cirrhosis. Although hepatic fibrogenesis progresses along a common pathway irrespective of the specific etiology, fibrosis in pediatric liver diseases has different histopathological patterns than in adults. In pediatric liver disease, as in adults, management choices may depend upon the stage of fibrosis at diagnosis. With early intervention, the progression of hepatic fibrosis can be slowed or halted, and in some situations, reversed. While liver biopsy is the gold standard for diagnosing and assessing the presence and degree of fibrosis, it has several disadvantages including the potential for sampling error, the risk of complications, the relatively high cost, and general poor acceptance by pediatric patients and their parents. MR elastography (MRE) is a relatively new imaging technique with the potential for allowing a safe, rapid, cost-effective, and non-invasive evaluation of a wide variety of hepatic diseases by quantitatively evaluating the stiffness of the liver parenchyma. The purpose of this article is to present our initial clinical experience and illustrate our modified technique for the application of liver MRE in pediatric patients at our medical center.

METHODS AND MATERIALS

Pediatric MRE techniques were developed and applied to over 45 patients scanned with our new protocol.

CONCLUSION

Liver MRE is a safe, non-invasive method for assessing hepatic fibrosis in pediatric patients.

Pre- and postoperative imaging of the Rex shunt in children: what radiologists should know

OBJECTIVE

The objective of this article is to illustrate the imaging features of patients with extrahepatic portal venous obstruction who are evaluated before or after a Rex shunt surgery.

CONCLUSION

The Rex shunt is a potentially curative surgical procedure that reestablishes physiologic hepatopetal portal flow. It is typically accomplished by interposing a vascular conduit between the superior mesenteric vein to the still patent intrahepatic portal venous system. This procedure results in resolution of portal hypertension.

Hepatic fibrosis in paediatric liver disease

Liver fibrosis is the common endpoint of chronic liver disease of variable aetiology. Liver injury induces excess deposition of extracellular matrix via inflammatory pathways, which in turn results in distortion of the vascular liver architecture. The two features combine to cause portal hypertension and reduced hepatocellular function. Diagnosis of liver fibrosis is made by liver biopsy, but non invasive tests like serological markers or elastographic methods are increasingly being recognized as useful tools in the diagnosis of fibrosis. Treatment options that exceed the treatment of the underlying liver disease are still largely experimental.

Transient elastography for assessment of fibrosis in paediatric liver disease

The prognosis and management of chronic liver diseases in children largely depend on the extent and progression of liver fibrosis, which is often the most important predictor of disease outcome, and thus influences the indication for potential therapy. Unfortunately, liver biopsy continues to be the gold standard for the staging and grading of fibrosis. Liver biopsy is an invasive and painful technique with several limitations. These limitations have led to the development of alternative noninvasive methods for the accurate assessment of fibrosis and for the maintenance of an acceptable risk/benefit ratio. In the last decades, transient elastography (TE) has received increasing consideration as a means of evaluating disease progression in paediatric chronic liver disease. TE is an accurate and reproducible methodology for identifying subjects without fibrosis or significant fibrosis, or with advanced fibrosis. In this review, we provide an outline of liver fibrosis in paediatric liver diseases, including fibrogenesis, and noninvasive techniques for the diagnosis and follow-up of fibrosis, and then focus on the characteristics of TE and on its strength in the assessment of liver fibrosis, paying particular attention to studies conducted in children.

The future of pediatric US

Despite advances in other modalities, US remains an essential technology in pediatric imaging. Improvements in technology provide increasingly detailed anatomical images, and new techniques show promise in providing novel anatomical as well as physiological and structural information. Other specialties are recognizing the value of US to their patients and are increasingly performing their own examinations. Economic and social factors are also influencing the development and use of US. This review will evaluate many of these issues and demonstrate that the future of pediatric US is bright and that pediatric radiologists can and should continue to be leaders in its use and development.

Liver fibrosis in paediatric liver diseases

Numerous paediatric liver diseases from different origins may be complicated by development of liver fibrosis and progression to cirrhosis. Although fibrogenesis, which represents a major driving force for the development of liver fibrosis, has common tracts whatever the aetiology, liver fibrosis has different histopathological patterns in paediatric liver disease. In these diseases management choices may depend upon the stage of liver fibrosis. Thus, the accurate estimation of histological pattern of liver fibrosis is important for the prevention of the subsequent complications. Liver biopsy has long been considered as a gold standard diagnostic method for assessing liver fibrosis. However, due to its several disadvantages, in the last decades alternative and accurate non-invasive means to estimate fibrosis are developed. In this review, we characterised the most frequent histological patterns of liver fibrosis in paediatric liver diseases. Furthermore, we describe use of liver biopsy in diagnosis and staging of liver fibrosis, list the alternative non-invasive techniques that have an emerging role in the assessment of liver fibrosis, and propose a management algorithm.

Evaluation of liver fibrosis with T2 relaxation time in infants with cholestasis: comparison with normal controls

BACKGROUND

The degree of hepatic fibrosis in biliary atresia (BA) correlates with the prognosis of the disease and thus, early diagnosis of liver fibrosis is clinically important. Liver biopsy is the gold standard for the evaluation of liver fibrosis, but it is an invasive procedure requiring sedation in children. Therefore, it is desirable to identify a noninvasive method for diagnosis and follow-up of hepatic fibrosis.

OBJECTIVE

The purpose of this study is to evaluate the possibility of quantifying liver fibrosis in infants by T2 relaxation time measurements.

MATERIALS AND METHODS

The institutional review board approved this prospective study and parental informed consent was obtained. During MR cholangiopancreatography using a 1.5-T MR scanner in infants with neonatal cholestasis, T2 relaxation time of the liver was calculated with the mean signal intensities measured on images obtained using spin-echo sequences (TR/TE, 2,000/20, 40, 60, 80, 100, 120, 140, 160 ms). A normal control study was performed during spinal MRI in infants with anorectal malformation and normal liver enzyme profiles. A liver biopsy was obtained in the children with cholestasis. The correlation between histopathological fibrosis stage and T2 relaxation time was evaluated by Kendall's Tau-b test.

RESULTS

Twenty-five infants (male: female, 12:13; age range 0-11 months, mean 3.2 months), 14 with neonatal cholestasis (9 BA and 5 non-BA) and 11 normal controls were included in this study. Relaxation times (mean ± standard deviation [SD]) for the liver were 57.8 ms ± 8.8 in the normal control group (n=11) and 56.8 ms ± 9.6 in the BA group (n=9) without statistically significant differences (P=0.811). T2 relaxation times were not significantly different between the low stage (≤ F1) and high stage (≥ F2) fibrosis (mean 57.8 vs 56.8; P=0.934).

CONCLUSION

T2 relaxation of a normal infant liver at 1.5-T had a mean value of 57.8 ms, which is comparable with adult data (46-57 ms). However, T2 relaxation time was not different in patients with BA and did not correlate with stage of fibrosis.

Management of portal hypertension in children

Management of portal hypertension in children has evolved over the past several decades. Portal hypertension can result from intrahepatic or extrahepatic causes. Management should be tailored to the child based on the etiology of the portal hypertension and on the functionality of the liver. The most serious complication of portal hypertension is gastroesophageal variceal bleeding, which has a mortality of up to 30%. Initial treatment of bleeding focuses on stabilizing the patient. Further treatment measures may include endoscopic, medical, or surgical interventions as appropriate for the child, depending on the cause of the portal hypertension. β-Blockers have not been proven to effectively prevent primary or secondary variceal bleeding in children. Sclerotherapy and variceal band ligation can be used to stop active bleeding and can prevent bleeding from occurring. Transjugular intrahepatic portosystemic shunts and surgical shunts may be reserved for those who are not candidates for transplant or have refractory bleeding despite medical or endoscopic treatment.