Spleen stiffness measurement by transient elastography to diagnose portal hypertension in children

Role of splenic hepatic elastography ratio in differentiating non-cirrhotic portal fibrosis and chronic liver disease in children and adolescents

BACKGROUND

Differentiation of Non-cirrhotic Portal Fibrosis (NCPF) from chronic liver disease (CLD) in children and adolescents with portal hypertension (PHT) is challenging especially in cases where liver stiffness measurement (LSM) and hepatic venous pressure gradient are higher. This objective of the current study was to evaluate the diagnostic accuracy of the splenic stiffness measurement (SSM)/LSM ratio in the diagnosis of NCPF.

METHODS

From January 2019 to December 2023, consecutive children and adolescents of 6 months to 18 years of age with PHT (CLD and NCPF) were prospectively enrolled. Transient elastography (TE) for SSM and LSM, upper gastrointestinal endoscopy (UGIE), liver biopsy/trans-jugular liver biopsy, abdominal imaging, and laboratory evaluation were done. The relationship of TE parameters for diagnosis of NCPF and CLD was evaluated. Receiver-operating characteristic (ROC) statistics were applied using R Studio-4.2.2 statistical software.

RESULTS

One hundred and forty seven with CLD and 27 patients with NCPF were evaluated. Median age was 10.0 (IQR 2.4-14.0) years; 68.4% were males. The AUROC of SSM/LSM ratio was better (0.992, 95%CI 0.982-1.0001) than LSM (0.945, 95%CI0.913-0.977) and SSM (0.626, 95%CI0.258-0.489) for the diagnosis of NCPF. SSM/LSM ratio cut-off of 3.67 predicted NCPF with an excellent sensitivity (100%), specificity (95.9%), and diagnostic accuracy (95.91%). The AUROC of SSM/LSM ratio was excellent and outperformed other TE parameters in the subgroups, i.e., LSM between 10 and 20 kPa (0.982, 95%CI 0.947-1.000), without clinically significant varices (CSV) (1.000, 95%CI 1.000-1.000) and with CSV (0.993, 95%CI 0.983-1.000). Diagnostic performance of SSM/LSM Ratio was better than LSM for discriminating NCPF from CLD using McNemar test (p = 0.01).

CONCLUSION

The SSM/LSM ratio is an excellent tool in differentiating NCPF from CLD.

Cholestasis after Kasai operation predicts portal hypertension in native liver survivors of biliary atresia: a multicenter study

PURPOSE

This study evaluated portal hypertension (PHT) and its predictors among native liver survivors (NLS) of biliary atresia (BA) after Kasai portoenterostomy (KPE).

METHODS

This was a multicenter study using prospectively collected data. The subjects were patients who remained transplant-free for 5 years after KPE. Their status of PHT was evaluated and variables that predicted PHT were determined by regression analysis and receiver operating characteristic (ROC) curve.

RESULTS

Six centers from East Asia participated in this study and 320 subjects with KPE between 1980 to 2018 were analyzed. The mean follow-up period was 10.6 ± 6.2 years. At the 5th year after KPE, PHT was found in 37.8% of the subjects (n = 121). Patients with KPE done before day 41 of life had the lowest percentage of PHT compared to operation at older age. At 12 months after KPE, PHT + ve subjects had a higher bilirubin level (27.1 ± 11.7 vs 12.3 ± 7.9 µmol/L, p = 0.000) and persistent jaundice conferred a higher risk for PHT (OR = 12.9 [9.2-15.4], p = 0.000). ROC analysis demonstrated that a bilirubin level above 38 µmol/L at 12 months after KPE predicted PHT development (sensitivity: 78%, specificity: 60%, AUROC: 0.75).

CONCLUSIONS

In BA, early KPE protects against the development of PHT among NLSs. Patients with persistent cholestasis at one year after KPE are at a higher risk of this complication. They should receive a more vigilant follow-up.

LEVEL OF EVIDENCE

Level III.

Transient elastography and von Willebrand factor as predictors of portal hypertension and decompensation in children

Background & Aims

Von Willebrand factor antigen (vWFAg), a protein measured to test the level of vWF released from the vascular endothelium has gained much attention as a marker for portal hypertension (PHT) severity. The objectives of this study were to investigate the use of vWFAg as a biomarker along with liver and spleen stiffness measurements by transient elastography as potential predictors of clinically significant varices (CSV), variceal bleeding (VB) and decompensation in children with PHT.

Methods

This observational prospective cohort study included 117 children (median age 10 [IQR 6-14] years) who underwent oesophagogastroduodenoscopy between January'2012 to November'2021 and a validation group of 33 children who underwent the same procedure between December'2021 to March'2023. Measurements of vWFAg and glycoprotein Ib binding activity of VWF (GPIbR) were available in 97 patients in the study group and in all patients in the validation group.Results: vWFAg and GPIbR were significantly higher in children with CSV (223 IU/dl and 166 IU/dl; p = 0.015 and p = 0.04, respectively) and VB (218 IU/dl and 174 IU/dl; p = 0.077 and p = 0.03, respectively) than in those without CSV or VB, respectively. Ninety-six patients had liver and spleen stiffness measurements. Spleen stiffness was significantly higher in patients with CSV compared to those without CSV (p = 0.003). In a chronic liver disease subgroup, a predictive scoring tool based on vWFAg, GPIbR, platelet count, and spleen/liver stiffness measurements could predict CSV with an AUROC of 0.76 (p = 0.04).

Conclusions

This study suggests the predictive value of vWF for CSV and VB increases when combined with spleen stiffness, with AUROCs of 0.88 and 0.82, respectively. Hence, a combination of biomarkers could assist clinicians in diagnosing CSV, preventing unnecessary invasive procedures.

Impacts and implications

Surveillance endoscopies in children with portal hypertension (PHT) have their own risks and non-invasive markers, such as von Willebrand factor antigen, glycoprotein Ib binding activity of VWF (GPIbR), and transient elastography could be used to predict clinically significant varices, variceal bleeding and disease compensation in children with PHT. Such non-invasive markers for PHT and varices are lacking in the paediatric population. The results show that von Willebrand factor and GPIbR along with transient elastography can be used to formulate a scoring system which can be used as a clinical tool by paediatric hepatologists to monitor the progression of PHT and risk of bleeding, and hence to stratify the performance of invasive endoscopic procedures under general anaesthesia. However, there is a need to validate the scoring system in children with portal vein thrombosis and for hepatic decompensation in a multi-centre registry in the future.

Ultrasound Elastography in Children

Ultrasound elastography is a novel ultrasound technique, being extensively researched in children in the last decade. It measures tissue elasticity with the observation of tissue response after an external stimulus. From research to clinical practice, ultrasound elastography has evolved significantly in liver fibrosis evaluation in children; however, several other applications of the technique are available in both clinical practice and research environments. Practically, in children any organ can be assessed, including the brain in early ages, along with muscle and connective tissue elasticity evaluation, spleen, kidney, skin, lymphatic tissue, etc. The elastography method, age, body mass index and technical points should be considered when performing ultrasound elastography. This review highlights its vast potential as a diagnostic tool in the pediatric population, where ultrasound is a dominant imaging tool; however, the indications and exam protocol for its clinical use in several fields in pediatrics have yet to be elucidated.

Splenic Stiffness Is the Best Predictor of Clinically Significant Varices in Children With Portal Hypertension

BACKGROUND AND AIMS

We studied splenic stiffness measurement (SSM) by transient elastography (TE) and portal hemodynamics parameters (PHDp) on Doppler as predictors of clinically significant varices (CSV) in children.

METHODS

All children of 6 months to 18 years of age with portal hypertension (PHT) (chronic liver disease, CLD and non-cirrhotic portal hypertension, NCPH) were enrolled. TE for spleen (SSM) and liver (liver stiffness measurement, LSM) and PHDp by Doppler ultrasonography were measured. Noninvasive indices for PHT were calculated. CSV were defined as esophageal varices ≥grade 2 and/or gastric varix. Binary logistic regression analysis (LRA) and receiver operating characteristic statistics were applied.

RESULTS

A total of 150 (120 CLD and 30 NCPH) children formed the study cohort. Prevalence of CSV was higher in NCPH than CLD [73.3% vs 53.3%, Odd's ratio (OR) 2.369, P = 0.04]. On LRA, SSM was found to be the only independent predictor of CSV in children with CLD [OR 1.19 (95% Confidence Interval (CI) 1.018-1.16), P = 0.000] as well as in NCPH [OR 1.088 (95% CI 1.018-1.16), P = 0.013]. This model improved prediction of CSV in CLD from 52.5% to 83.9% and in NCPH from 73.3% to 86.7%. In children with CLD, SSM at a cut-off ≥27.6 kPa and in NCPH, SSM at a cut-off ≥29.5 kPa predicted CSV. In children with CLD, SSM correlated with LSM ( R = 0.610, P <0.001) and with noninvasive PHT indices except aspartate aminotransferase-to-platelet ratio index.

CONCLUSION

SSM is the best noninvasive predictor of CSV in childhood CLD and NCPH and can be used as screening test for endoscopy in children with PHT.

Non-invasive assessment of fibrosis regression and portal hypertension in patients with advanced chronic hepatitis C virus (HCV)-associated liver disease and sustained virologic response (SVR): 3 years follow-up of a prospective longitudinal study

Long-term effects on cirrhosis and portal hypertension of direct antiviral agent (DAA)-based eradication of hepatitis C virus (HCV) are still under debate. We analysed dynamics of liver and spleen elastography to assess potential regression of cirrhosis and portal hypertension 3 years post-treatment. Fifty-four patients with HCV-associated cirrhosis and DAA-induced SVR were included. Liver and spleen stiffness were measured at baseline (BL), end of treatment (EOT), 24 weeks after EOT (FU24) and 1, 2 and 3 (FU144) years post-treatment by transient liver elastography (L-TE) and point shear wave elastography (pSWE) using acoustic radiation force impulse (ARFI) of the liver (L-ARFI) and spleen (S-ARFI). Biochemical, virological and clinical data were also obtained. Liver stiffness assessed by L-TE decreased between BL [median (range), 32.5(9.1-75) kPa] and EOT [21.3(6.7-73.5) kPa; p < .0001] and EOT and FU144 [16(4.1-75) kPa; p = .006]. L-ARFI values improved between EOT [2.5(1.2-4.1) m/s] and FU144 [1.7(0.9-4.1) m/s; p = .001], while spleen stiffness remained unchanged. Overall, L-TE improved in 38 of 54 (70.4%) patients at EOT and 29 of 38 (76.3%) declined further until FU144, whereas L-ARFI values decreased in 30/54 (55.6%) patients at EOT and continued to decrease in 28/30 (93.3%) patients at FU144. Low bilirubin and high albumin levels at BL were associated with improved L-ARFI values (p = .048) at EOT or regression of cirrhosis (<12.5 kPa) by L-TE at FU144 (p = .005), respectively. Liver stiffness, but not spleen stiffness, continued to decline in a considerable proportion of patients with advanced liver disease after HCV eradication.

Spleen stiffness measurement by shear wave elastography using acoustic radiation force impulse in predicting the etiology of splenomegaly

PURPOSE

To measure spleen stiffness by shear wave elastography (SWE) using acoustic radiation force impulse (ARFI) in patients with splenomegaly and to evaluate utility of elastography technique in identifying etiology of splenomegaly.

METHODS

Sixty-one treatment-naïve patients with splenomegaly were enrolled. The control group consisted of 20 healthy subjects without history of any disease including diabetes and hypertension, alcohol consumption, or biochemical or ultrasonographic findings indicating hepatic and renal diseases. B-mode ultrasonography and elastographic examinations were performed by a radiologist blinded to the participants. Spleen stiffness was measured by SWE using ARFI. Shear wave velocity (SWV) values were given in m/s.

RESULTS

Splenomegaly patients were assigned into three groups according to their etiologies as hepatoportal (n = 21), myeloproliferative (n = 23), and infectious (n = 17). Splenomegaly groups and control group were comparable regarding age and sex. Spleen size was higher in the splenomegaly groups than in the controls. Median SWV was significantly higher in the hepatoportal (3.85 m/s) and myeloproliferative (3.42 m/s) groups than in the infectious (2.66 m/s) and control (2.22 m/s) groups. The correlation between SWV and spleen size was not significant in any of the groups. The cut-off value was 3.42 (sensitivity 80.9%, specificity 56.5%) in distinguishing hepatoportal from myeloproliferative etiology; 3.02 (sensitivity 100%, specificity 100%) in distinguishing hepatoportal from infectious etiology; and 2.84 (sensitivity 91.3%, specificity 88.2%) in distinguishing myeloproliferative from infectious etiology.

CONCLUSION

Spleen stiffness measured by elastographic techniques in splenomegaly patients was higher than that in healthy subjects. SWV appeared to be beneficial in predicting the etiology of splenomegaly.

Acoustic radiation force impulse imaging: normal values of spleen stiffness in healthy children

BACKGROUND

Acoustic radiation force impulse (ARFI) imaging is a noninvasive ultrasound elastography technique for evaluating tissue stiffness. The association of liver and spleen stiffness provides additional information in the assessment of portal hypertension. The technique and normal values of spleen stiffness by point shear wave elastography (p-SWE) in pediatrics have not been well documented.

OBJECTIVE

Our aim is to describe the feasibility and normal ARFI elastography values in the spleen for healthy children and to compare measurements in two different probe positions (the axial and sagittal planes).

MATERIALS AND METHODS

Spleen p-SWE using ARFI values were measured with a 6C1 probe in 102 healthy children (age range: 8 weeks to 17 years) divided into four age groups. An average of nine (standard deviation: two) spleen stiffness measurements were taken during free breathing in each plane (axial and sagittal). The impact of age and measurement plane in the spleen was analyzed using multivariate models.

RESULTS

There was no significant difference in spleen stiffness values taken at different ages, with an average of the medians of 2.43±0.31 m/s. There was no significant difference based on probe orientation: sagittal plane (median: 2.46±0.29 m/s) and axial plane (median: 2.43±0.32 m/s) with Student's t-test P=0.18. The mean depth of measurement varied between 2.3 cm and 3.7 cm, according to age.

CONCLUSION

Normal spleen stiffness values using ARFI imaging in children do not vary with age and correspond to a median of 2.43 m/s. No significant difference was found when using different probe positions.

Splenic stiffness and platelet count to predict varices needing treatment in pediatric extrahepatic portal vein obstruction

BACKGROUND

Surveillance endoscopy to detect varices needing treatment (VNT) is important to prevent bleeding and morbidity in portal hypertension. In adult and pediatric cirrhosis, platelet count and liver stiffness measurement (LSM) are useful in selecting patients for endoscopy. Such recommendations do not exist for extrahepatic portal vein obstruction (EHPVO). Splenic stiffness measurement (SSM) has been studied in adult and pediatric EHPVO with conflicting results and methodological errors. This study evaluates the role of platelet counts and SSM to predict VNT and bleeding in pediatric EHPVO while comparing LSM and SSM between pediatric EHPVO and controls.

METHODS

One hundred and seven children (55 with EHPVO and 52 controls) were recruited. Clinical, biochemical, hematological, and radiographic parameters of all children were noted. All children with EHPVO underwent endoscopy.

RESULTS

Of the 55 children with EHPVO, 48 (87.3%) had VNT. There was no difference in the platelet counts (85,000/mm³ vs. 120,000/mm³, p = 0.58) and SSM (3.62 vs. 3.19, p = 0.05) between EHPVO children with VNT and those without. They had poor sensitivity and specificity to predict VNT. EHPVO children with bleeding had higher SSM that those without. LSM was higher among EHPVO than among controls (1.19 vs. 1.10, p = 0.003). Those with LSM higher than controls had normal liver histology.

CONCLUSION

SSM is higher in EHPVO bleeders but SSM and platelet counts are unreliable to predict VNT in pediatric EHPVO. Surveillance endoscopies may be needed in all pediatric EHPVO until better screening strategies are available.

TRIAL REGISTRATION

Not applicable.

Role of noninvasive tools for prediction of clinically evident portal hypertension in children

BACKGROUND

Noninvasive tools (NITs) for predicting varices in children with portal hypertension (PHTN) are infrequently used.

METHODS

Eighty-five consecutive, treatment-naïve children with PHTN and 97 controls were enrolled study from July 2017 to November 2018. Each case was evaluated by esophagogastroduodenoscopy (EGD) and various NITs: platelet spleen size Z (PSZ), clinical prediction rule (CPR), King's variceal prediction rule (KVaPS), Splenic stiffness (SSM) and liver stiffness measurement (LSM) by point shear wave elastrography (pSWE).

RESULTS

Had PHTN due to extra hepatic portal vein obstruction (EHPVO) and 70% due to cirrhosis [chronic liver disease (CLD)]. Sixty-five percent of PHTN cases had varices. Children with varices had lower platelet counts, lower albumin and larger spleens. SSM and LSM were significantly higher in cases as compared with controls. SSM was significantly higher in cases with varices than those without. SSM and LSM, at cutoffs of 3.8 and 3.2 kPa, respectively, discriminated PHTN cases from controls with an area under the curve (AUROC) of 0.67 (0.59-0.74). Both SSM and LSM predicted varices in CLD, but in EHPVO, only SSM predicted varices. SSM of 5.2 and 12.8 kPa, in CLD and EHPVO subgroups, respectively, had AUROC of 0.73 and 0.94 for variceal prediction. Blood-based NITs performed better in the CLD subgroup: aspartate aminotransferase platelet ratio index, CPR and KVPS predicted severity of PHTN with AUROC of 0.81, 0.92 and 0.93, respectively.

CONCLUSIONS

Blood-based NITs outperform elastography for prediction of PHTN/varices in children with CLD. SSM by pSWE is a better predictor of varices than LSM, especially in the EHPVO subgroup.

Spleen stiffness measurement as a non-invasive test to evaluate and monitor portal hypertension in children with extrahepatic portal vein obstruction

PURPOSE

The aim of the study was to test the feasibility of spleen stiffness measurement (SSM) by two-dimensional shear wave elastography (2D-SWE) and compare data on its diagnostic use with upper gastrointestinal endoscopy in children with extrahepatic portal hypertension (EHPH) before and after surgery.

METHODS

A total of 44 children were included in this study [34 children with EHPH (main group)] and 10 controls (7.57 ± 1.22 years), who underwent ultrasonography including SSM by 2D-SWE. Patients in the main group also underwent upper gastrointestinal endoscopy (UGE) and CT angiography. The main group was divided into three subgroups: Group A: patients with EHPH without large spontaneous portosystemic shunts (n = 15); Group B: patients with EHPH with large spontaneous portosystemic shunts (n = 9); Group C: patients with EHPVO and after surgical portosystemic shunts (n = 10).

RESULTS

According to UGE, children in group A had significantly higher grades of esophageal varices (EV) (2.3 ± 0.14; p < 0.001) compared to those in groups B and C. After surgical shunting procedures (in group C), the grade of EV declined to 0.37 ± 0.14. There was significant difference (p < 0.001) in the mean SS of children in group A (70 ± 4.64 kPa) compared to those in group B (37.04 ± 4.62 kPa) and group C (26.3 ± 2.9 kPa). After surgery, SS decreased but remained elevated compared with controls (26.3 ± 2.9 vs 17.85 ± 1.3 kPa; p = 0.016). The SS showed a small but significant correlation with grades of EV (r = 0.56, p = 0.002).

CONCLUSIONS

The SS measured by 2D-SWE is feasible in children with EHPH and the results reflect the presence or degree of EV, thus elastography of spleen is useful in monitoring portal hypertension before and after shunt surgeries.

Spleen and Liver Stiffness to Detect Esophageal Varices in Children with Biliary Atresia

OBJECTIVES

The aim of the study was to determine the accuracy of noninvasive parameters, such as liver (LS) and spleen stiffness (SS) to detect esophageal varices (EV) in children with biliary atresia (BA).

METHODS

Children with BA between 2000 and 2015 were recruited. All underwent esophagogastroduodenoscopy and transient elastography. Demographic data, laboratory investigations, alanine transferase-to-platelet ratio index (APRI), and Varices Prediction Rule (VPR) score were collected.

RESULTS

A total of 51 children (mean age 10.63 years, standard deviation (SD) = 6.08 years; 53% boys) were enrolled. There were differences in onset and outcome of portoenterostomy, spleen palpablility, platelet count, albumin, LS, SS, and VPR between the varice and varice-free groups (P < 0.05). In the varice group, the median LS was 18.12 (interquartile ratio, IQR 13.15-19.12) and the median SS was 46.85 (IQR 25.95-54.55) kPa. In the varice-free group, the median LS was 7.85 (IQR 5.88-16.75) and the median SS was 16.54 (IQR 11.75-21.75) kPa. Both LS and SS were higher in the varice than the varice-free group (P < 0001). The area under the receiver operating characteristic curve of LS, SS, spleen palpability, platelet count, APRI, and VPR were 0.734, 0.870, 0.817, 0.810, 0.751, and 0.794, respectively. Using a cut-off value of 12.5 kPa for LS, the sensitivity and specificity were 80 and 70%, respectively. Using a cut-off value of 28.9 kPa for SS, the sensitivity and specificity were 75 and 87%, respectively. Combination of LS and SS to diagnose varices increased the specificity to 93%.

CONCLUSIONS

SS as a single marker had the best diagnostic value to predict esophageal varices in children with BA. The combination of SS and LS furthermore, increased the diagnostic yield.

Spleen stiffness by 2-D shear wave elastography is the most accurate predictor of high-risk esophagogastric varices in children with biliary atresia

AIM

Esophagogastric variceal hemorrhage is a cause of poor prognosis in patients with biliary atresia (BA). To prevent variceal hemorrhage, simple and reliable screening methods for high-risk esophagogastric varices (HR-EGV) are needed. We evaluated the efficacy of liver stiffness (LS) and spleen stiffness (SS) as measured by 2-D shear wave elastography (2D-SWE), which was reported to be more accurate than transient elastography, for detecting HR-EGV in children with BA.

METHODS

Thirty-four children with BA were enrolled. Both LS and SS were measured by 2D-SWE. The presence of large esophageal varices or esophageal varices of any size with red wale marking and/or the presence of gastric varices along the cardia were defined as HR-EGV. Clinical data were collected and previously reported prediction indices for varices were calculated.

RESULTS

Liver stiffness and SS were obtained from all patients. Fourteen patients showed HR-EGV. Significantly different variables between patients with and without HR-EGV were as follows: spleen diameter (116 mm vs. 95 mm), clinical prediction rule (104.7 vs. 124.7), King's variceal prediction score (78.8 vs. 99.4), aspartic aminotransferase-to-platelet ratio index (2.03 vs. 0.98), LS (2.63 m/s vs. 1.87 m/s), and SS (4.44 m/s vs. 3.69 m/s). The highest area under the receiver operating characteristic curve for detecting HR-EGV was that for SS (0.900), and the cut-off SS of 4.12 m/s yielded 92.9% sensitivity and 90% specificity. The intraclass correlation coefficient for intra-observer reproducibility was 0.828.

CONCLUSIONS

Spleen stiffness from 2D-SWE offered the most accurate predictor of HR-EGV in BA children.

Diagnostic Performance of Ultrasound Elastography for Evaluating Portal Hypertension in Children: A Systematic Review and Meta-analysis

OBJECTIVES

To assess the diagnostic performance of ultrasound (US) elastography in evaluating portal hypertension in children and compare the liver and spleen stiffness values between the portal hypertension and control groups.

METHODS

Studies in the MEDLINE and Embase databases were selected that investigated the diagnostic performance of US elastography in children with portal hypertension up to December 21, 2017. Pooled sensitivity and specificity data were assessed by hierarchical logistic regression modeling.

RESULTS

Eleven studies were included in the systematic review, and a meta-analysis could be conducted in 7 of these publications to evaluate the diagnostic performance of US elastography. The summary sensitivity and specificity of this method for liver stiffness were 90% (95% confidence interval [CI], 83%-94%) and 79% (95% CI, 73%-84%), respectively, and the area under the hierarchical summary receiver operating characteristic curve was 0.92 (95% CI, 0.90-0.94). A subgroup analysis of 5 transient elastographic studies revealed similar diagnostic performance (sensitivity, 90%; specificity, 78%). In 10 of the 11 studies that investigated liver stiffness and 2 of the 3 studies that also measured spleen stiffness, patients in the portal hypertension group had a significantly higher stiffness value than the control group (P < .05).

CONCLUSIONS

Ultrasound elastography shows good performance in diagnosing portal hypertension and can identify significant differences in liver and spleen stiffness in children with this condition. This method thus has considerable potential as a noninvasive tool for screening portal hypertension-related complications in children with chronic liver disease.

Spleen Stiffness Measurement Using 2-Dimensional Shear Wave Elastography: The Predictors of Measurability and the Normal Spleen Stiffness Value

OBJECTIVES

To investigate the success rate of spleen stiffness measurement and factors that affect measurement success and to determine the spleen stiffness value of normal individuals by 2-dimensional shear wave elastography.

METHODS

The spleen and liver stiffnesses of 313 consecutive patients were measured with SWE. The body mass index, abdominal wall thickness, spleen size, and liver stiffness of the patients were evaluated to identify factors associated with successful measurement of spleen stiffness. Patients were grouped by body mass index, spleen size, and liver stiffness, and the success rates and mean spleen stiffness values of the groups were compared. Independent predictors for successful spleen stiffness measurement and their cutoff values were evaluated. The mean spleen stiffness values of patients considered to have normal spleen stiffness were investigated.

RESULTS

The overall success rate of spleen stiffness measurement was 52.9%. It was significantly higher in nonobese than in obese patients and in patients with splenomegaly and liver cirrhosis. The spleen stiffness value was higher in the splenomegaly group than the nonsplenomegaly group (P < .001) and increased as liver stiffness increased (P < .001). There was no significant difference in spleen stiffness values between the obese and nonobese groups. Abdominal wall thickness and splenic longitudinal diameter were identified as independent predictors of successful spleen stiffness measurement, and their cutoff values were 17.2 mm or less and greater than 9.4 cm, respectively. The mean spleen stiffness value ± SD of the normal patient group was 20.5 ± 5.4 kPa.

CONCLUSIONS

The success rate of spleen stiffness measurement is lower than that of liver stiffness measurement. Spleen stiffness measurement is affected by abdominal wall thickness and spleen size.

Advances in diagnosis of chronic liver diseases in pediatric patients

BACKGROUND

Chronic liver diseases (CLD) present important clinical problem in children with various age-dependent causes. Nonalcoholic fatty liver disease (NAFLD) with its increasing prevalence is a major problem with regard to its timely recognition and the need for long-term disease monitoring. At present, a perfect non-invasive method for the evaluation of liver fibrosis is not available.

METHODS

A non-systematic literature search was performed to summarize the current knowledge about transient elastography (TE) with controlled attenuation parameter (CAP) in children with CLD. Ovid MEDLINE, Ovid EMBASE, Google scholar, and The Cochrane Library databases were searched for relevant articles evaluating TE in the pediatric population.

RESULTS

Normal values of liver stiffness measurements (LSM) according to the age are given, as well as the advantages and disadvantages of the method. The utility of TE in specific liver disease in pediatric population is summarized.

CONCLUSIONS

TE with CAP is a valuable non-invasive method for the liver-damage assessment. Clinical interpretation of TE results should be made in parallel with the assessment of the patient's demographics, disease etiology, and essential laboratory parameters.

Transient Elastography Measurements of Spleen Stiffness as a Predictor of Clinically Significant Varices in Children

OBJECTIVES

Investigate the use of spleen stiffness measurements (SSMs), measured by transient elastography (TE), for the prediction of clinically significant varices (CSV) in children with portal hypertension.

METHODS

This observational cohort study included children selected for endoscopy, as per department protocol, between September 2015 and June 2016. Those included underwent single TE FibroScan for liver stiffness measurements and SSM. Clinical and laboratory data were collected and variceal prediction scores were calculated at time of elastography.

RESULTS

In total 67 children (32 boys) underwent TE. Fifty-two children (25 boys) had chronic liver disease (CLD), 15 (7 boys) portal vein thrombosis (PVT). In all children SSM was the best predictor of CSV+ve, with an optimal cut-off value of 38.0 kPa (area under the receiver operator curve [AUROC] = 0.92, sensitivity = 89%, specificity = 82%, P < 0.01). In the CLD group SSM was also the best predictor, with an optimal cut-off value of 38.05 kPa (AUROC = 0.90, sensitivity = 84%, specificity = 87%, P < 0.01). In the PVT group only SSM was predictive of CSV+ve, with an optimal cut-off value of 16.8 kPa (AUROC = 1.00, sensitivity = 100%, specificity = 100%, P < 0.001). For the prediction of GI bleeding (n = 6), liver stiffness measurement performed the best, with an optimal cut-off value of 34.3 kPa (AUROC = 0.84, sensitivity of 80%, specificity of 88%, P = 0.01).

CONCLUSIONS

SSM was the greatest predictor of CSV+ve in the whole cohort, and individual CLD and PVT groups. SSM could be used as a noninvasive screening tool for children with portal hypertension to stratify the risk of having CSV.

Noninvasive Assessment of Portal Hypertension in Advanced Chronic Liver Disease: An Update

The assessment of portal hypertension is a relevant step in the evaluation of newly diagnosed advanced chronic liver disease (ACLD). The current gold standard includes the invasive evaluation of hepatic venous pressure gradient (HVPG) and endoscopy. However, noninvasive or minimally invasive techniques to assess portal hypertension have been proposed and well established. In the present manuscript, we review clinical studies on the use of noninvasive or minimally invasive techniques to assess portal hypertension in ACLD patients.

Non-invasive Markers of Portal Hypertension: Appraisal of Adult Experience and Potential Utilisation in Children

Portal hypertension (PHT) is a significant cause of morbidity and mortality in children with chronic liver disease and portal vein obstruction. Increased portal pressure results in variceal formation along the gastrointestinal (GI) tract resulting in major bleeding. Identifying children with significant PHT who are more likely to suffer GI bleeding has been challenging and the role of surveillance upper GI endoscopy has been debated. This review analyses research done on serum biomarkers and imaging techniques as possible predictors of significant PHT. We evaluated the research performed on adult population, as well as the limited work done on children, to identify promising areas for future research. A literature search was conducted on "PubMed." Several search terms were used including "portal hypertension," "paediatric portal hypertension," "non-invasive markers of portal hypertension," "spleen stiffness," "liver stiffness," "elastography," and "endothelial damage." The articles included were selected based on their relevance to the purpose of our review. The research suggests a combination of several biomarkers, in addition to an imaging technique such as transient elastography or magnetic resonance elastography, would allow for the best prediction of significant varices. The most promising indicators would be those that are applicable in both intra- and extra-hepatic causes of PHT. Further research on these predictors in children with PHT is required to determine their potential role as selection criteria for PHT and stratification of surveillance GI endoscopies.

Cystic Fibrosis-related Liver Disease: Research Challenges and Future Perspectives

OBJECTIVES

Hepatobiliary complications are a leading cause of morbidity and mortality in cystic fibrosis (CF) patients. Knowledge of the underlying pathological aspects and optimal clinical management is, however, sorely lacking.

METHODS

We provide a summary of the lectures given by international speakers at the European Society for Paediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN) monothematic conference on cystic fibrosis-related liver disease (CFLD) held in Paris in January 2016, to discuss the status of our current knowledge of liver disease in CF patients, to define the critical areas that need to be addressed, and to resolve actions to elucidate relevant mechanisms of disease to optimise future therapeutic options.

CONCLUSIONS

The need for a universal consensus on the definition of CFLD to clarify disease stage and to identify relevant biomarkers to assess disease severity was highlighted. A deeper understanding of the pathophysiology and prognostic factors for the long-term evolution of CFLD is fundamental to move forward and has a strong bearing on identifying potential treatments. Novel experimental models and new treatment options under investigation are discussed and offer hope for the near future of CFLD.

Liver Stiffness Measured by Shear-wave Elastography for Evaluating Intrahepatic Portal Hypertension in Children

OBJECTIVES

The aim of the study was to correlate liver stiffness (LS) and hepatic venous-pressure gradient (HVPG) and to evaluate the diagnostic performance of shear-wave elastography (SWE) for predicting clinically significant portal hypertension in children with suspected liver diseases, in consideration of the reliability criteria.

METHODS

We identified 33 SWEs from 32 children who underwent HVPG measurement within 2 weeks between June 2012 and October 2015. The correlation between LS and HVPG was assessed. The diagnostic performance for predicting clinically significant portal hypertension (HVPG ≥ 10 mmHg) was assessed using the receiver-operating characteristic curve. Reliable measurement was evaluated based on the coefficient of variation (CV).

RESULTS

LS was significantly correlated with HVPG (r = 0.742, P < 0.001). The area under the receiver-operating characteristic curve for predicting clinically significant portal hypertension was 0.914, and the best cutoff value of 18.4 kPa showed sensitivity of 87.5% and specificity of 84.0%. LS measurements having CV ≤ 0.2 were significantly correlated with HVPG (r = 0.774, P < .001), whereas those having CV > 0.2 did not show a significant correlation with HVPG (r = 0.598, P = 0.089).

CONCLUSIONS

SWE had excellent diagnostic performance for predicting clinically significant portal hypertension in children with suspected liver diseases. LS measurements having CV ≤ 0.2 may possibly be used as a reliability criterion in SWE measurement.

Regression of fibrosis and portal hypertension in HCV-associated cirrhosis and sustained virologic response after interferon-free antiviral therapy

It is still controversial, whether and to what amount cirrhosis and portal hypertension are reversible in patients with hepatitis C virus (HCV)-associated cirrhosis and sustained virologic response (SVR) after interferon-free antiviral therapy. In this study, we prospectively evaluated dynamics of liver and spleen stiffness in HCV-infected patients with advanced liver disease and SVR after interferon-free treatment. A total of 54 patients with HCV-associated cirrhosis and SVR were included. Liver and spleen stiffness was measured at therapy baseline (BL), end of treatment (EOT) and 24 weeks after EOT (FU24) by transient liver elastography (L-TE) as well as by acoustic radiation force impulse of the liver (L-ARFI) and spleen (S-ARFI), as well as biochemical, virologic and clinical data. Improvement of liver and spleen stiffness was found in 44 of 50 (88%), 31 of 54 (57%) and 25 of 54 (46%) of patients assessed by L-TE, L-ARFI and S-ARFI between baseline and FU24. Liver stiffness assessed by L-TE improved between BL [median (range), 32.5 (9.1-75) kPa] and EOT [median (range), 21.3 (6.7-73.5) kPa; (P<.0001)], and between BL and FU24 [median (range), 21.2 (5.4-70) kPa; (P<.0001)]. Liver stiffness assessed by L-ARFI improved between BL [median (range), 2.7 (1.2-4.1) m/s] and FU24 [median (range), 2.4 (1.2-3.9) m/s; P=.002), while spleen stiffness remained unchanged. Our data suggest that improvement of liver stiffness may be rather due to reduced necroinflammation and may be due to a less extent to regression of cirrhosis, as dynamics of liver stiffness improvement was more pronounced between BL and EOT than BL and FU24.

Transient Elastography for Spleen Stiffness Measurement in Patients With Cirrhosis: Role in Degree of Thrombocytopenia

OBJECTIVES

The purpose of our study was to evaluate the relationship between spleen stiffness measured by transient elastography and the degree of thrombocytopenia in patients with liver cirrhosis.

METHODS

A total of 67 patients with liver cirrhosis were prospectively enrolled in the study. All patients underwent single-day hematologic and biochemical tests, sonography, and transient elastography of the liver and spleen. Thrombocytopenia was categorized as mild (platelet count, 75,000-150,000/μL), moderate (50,000-75,000/μL), and severe (<50,000/μL).

RESULTS

The degree of thrombocytopenia was significantly correlated with spleen stiffness (P = .001) and spleen size (P = .002) but not with liver stiffness (P = .086). In patients without splenomegaly, spleen stiffness values were significantly higher in patients with thrombocytopenia than in those without thrombocytopenia (P = .035). In patients with splenomegaly, spleen stiffness values were significantly higher in patients with moderate to severe thrombocytopenia than in those with a normal platelet count or mild thrombocytopenia (P = .007). Compared to liver stiffness, spleen stiffness showed a better and statistically significant correlation with platelet count and spleen size in patients with cirrhosis.

CONCLUSIONS

The degree of thrombocytopenia was directly correlated with spleen stiffness, irrespective of the presence of splenomegaly. The clinical phenomenon of unexpected thrombocytopenia may be explained by a subtle or irreversible change in spleen stiffness.

Ultrasonography: Applications in Pediatric Abdomen

Ultrasonography (US) is a valuable imaging tool for evaluation of different clinical conditions in children, in general and abdominal conditions, in particular. The interest in US derives primarily from the lack of ionizing radiation exposure, low cost, portability, real-time imaging and Doppler capabilities. In addition, US application requires no preparation or sedation, making it particularly attractive in the pediatric population. Because of these advantages, US has been adopted as the primary imaging tool for evaluation of a number of pediatric abdominal conditions that would have involved the use of ionising radiation in the past, e.g., pyloric stenosis, intussusception and various renal and bladder abnormalities, to name a few. Certain limitations, however, are inherent to US including large body habitus, excessive bowel gas, postoperative state and the learning curve. In addition, pediatric US is particularly challenging as the children are frequently unable to co-operate for breath holding and many of them are crying during the scanning. In the present review, the authors discuss the various applications of US in the evaluation of pediatric abdomen.

White Paper on P4 Concepts for Pediatric Imaging

Over the past decade, innovations in the field of pediatric imaging have been based largely on single-center and retrospective studies, which provided limited advances for the benefit of pediatric patients. To identify opportunities for potential "quantum-leap" progress in the field of pediatric imaging, the ACR-Pediatric Imaging Research (PIR) Committee has identified high-impact research directions related to the P4 concept of predictive, preventive, personalized, and participatory diagnosis and intervention. Input from 237 members of the Society for Pediatric Radiology was clustered around 10 priority areas, which are discussed in this article. Needs within each priority area have been analyzed in detail by ACR-PIR experts on these topics. By facilitating work in these priority areas, we hope to revolutionize the care of children by shifting our efforts from unilateral reaction to clinical symptoms, to interactive maintenance of child health.

Acoustic radiation force impulse quantification of spleen elasticity for assessing liver fibrosis

PURPOSE

The purpose of this study is to assess the correlation between liver fibrosis and spleen stiffness measured by ARFI in patients with chronic viral hepatitis (B or C) and to explore the possible complementary role of spleen and liver ARFI in grading liver fibrosis.

METHODS

84 subjects (51 patients, 33 healthy volunteers) were enrolled. ARFI of the spleen and the liver was performed. Patients subsequently underwent liver biopsy for grading liver fibrosis according to Knodell scoring system. Multivariate logistic regression and decision tree analysis were adopted to test the relationship between spleen and liver stiffness (independent variables) and liver fibrosis (F1< vs. ≥F3). Leave-One-Out Cross-Validation was used for validating the predictive classification models. Area under the ROC curve (AUROCC) was used as accuracy metric.

RESULTS

Spleen ARFI was able to discriminate early (F1) from severe (≥F3) liver fibrosis with an optimal cut-off of 3.05 m/s: AUROCC 0.807, cross-validated AUROCC 0.614. Liver ARFI was superior to spleen ARFI, using a cut-off of 2.11 m/s: AUROCC 0.879, cross-validated AUROCC 0.672. Neither spleen nor liver ARFI was able to differentiate healthy volunteers from F1 patients. Odds ratios derived from logistic regression were 23.1 and 9.9 for liver and spleen ARFI, respectively; resulting AUROCC was 0.905 (cross-validated 0.848). A decision tree considering the sequential use of liver and spleen ARFI with cut-off of 2.14 and 3.39 m/s, respectively, resulted in AUROCC of 0.903 (cross-validated 0.7).

CONCLUSIONS

Spleen ARFI has the potential to discriminate early from severe liver fibrosis. Spleen and liver ARFI, when combined, show a better discriminative power than liver ARFI alone.

Ultrasound Elastography and MR Elastography for Assessing Liver Fibrosis: Part 2, Diagnostic Performance, Confounders, and Future Directions

OBJECTIVE

The purpose of the article is to review the diagnostic performance of ultra-sound and MR elastography techniques for detection and staging of liver fibrosis, the main current clinical applications of elastography in the abdomen.

CONCLUSION

Technical and instrument-related factors and biologic and patient-related factors may constitute potential confounders of stiffness measurements for assessment of liver fibrosis. Future developments may expand the scope of elastography for monitoring liver fibrosis and predict complications of chronic liver disease.