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

Liver fibrosis assessment in pediatric population - can ultrasound elastography be an alternative method to liver biopsy? A systematic review

Liver diseases of various etiologies are becoming increasingly common in the pediatric population. So far, the gold diagnostic standard in these disorders is liver biopsy. This procedure is invasive, painful and requires general anesthesia in this group of patients. Due to the continuous development of new research techniques, such as liver elastography, it is necessary to evaluate them in the context of their diagnostic usefulness. Ultrasound elastography, as a quick and effective method, is being used more and more often in the assessment and monitoring of liver dysfunction in both adults and children. There are several techniques of liver elastography, such as transient elastography, shear wave elastography consisting of various subtypes such as two-dimensional shear wave elastography, acoustic radiation force impulse and point shear wave elastography, which differ in terms of the measurement technique and the achieved results. The purpose of our review was to determine whether techniques of liver elastography could replace liver biopsy. Although now, based on the analyzed papers, elastography cannot replace liver biopsy, in our opinion, the role of this tool in monitoring pediatric patients with liver diseases will grow in the coming years.

Use of transient elastography to assess hepatic steatosis and fibrosis in patients with juvenile idiopathic arthritis during methotrexate treatment

OBJECTIVES

This study aimed to assess the prevalence and identify predictors of hepatic steatosis and fibrosis in patients with juvenile idiopathic arthritis (JIA) during methotrexate treatment.

METHOD

This cross-sectional study included JIA patients who had received methotrexate for > 1 year. Laboratory data including liver chemistry and lipid profiles were collected. Liver stiffness measurements (LSM) and controlled attenuation parameters (CAP) were determined by transient elastography. Significant hepatic fibrosis was defined as LSM > 7 kilopascal (kPa), and hepatic steatosis was defined as CAP > 225 decibel/meter (dB/m). Logistic regression analysis was performed to identify predictors associated with hepatic steatosis and fibrosis.

RESULTS

Of 60 patients, 66.7% were female, and the median age (IQR) was 12.8 (10.6-15.0) years. The median duration of methotrexate usage (IQR) was 45 (22-85) months, and the median cumulative dose of methotrexate (IQR) was 3768 (1806-6466) mg. The median LSM (IQR) and CAP (IQR) were 4.1 (3.4-4.6) kPa and 191.0 (170.3-223.8) dB/m, respectively. No patients had transient elastography-defined hepatic fibrosis, whereas 21.7% had hepatic steatosis. A body mass index Z-score > 1 (OR 5.71 [95%CI 1.31-24.98], p = 0.021) and higher cumulative dose of methotrexate (OR 1.02 [95%CI 1.00-1.04], p = 0.041) were associated with hepatic steatosis, whereas the cumulative dose of steroids was not (OR 1.00 [95%CI 1.00-1.01], p = 0.097).

CONCLUSIONS

Hepatic steatosis is common among JIA patients receiving methotrexate, but none had transient elastography-defined hepatic fibrosis. Overweight/obese JIA adolescents and patients with a high cumulative dose of methotrexate are at risk for hepatic steatosis. Key Points •Long-term low-dose methotrexate usage and the concomitant use of other DMARDs did not increase the risk of hepatic fibrosis in JIA patients. •The prevalence of hepatic steatosis in JIA patients receiving methotrexate was higher than in a healthy pediatric population. •Overweight/obesity and a higher cumulative dose of methotrexate were predictors of hepatic steatosis.

Non-invasive Measurement of the Viscoelasticity of the Optic Nerve and Sclera for Assessing Papilledema: A Pilot Clinical Study

OBJECTIVE

The purpose of this study was to evaluate our novel ultrasound vibro-elastography (UVE) technique for assessing patients with papilledema by non-invasively measuring shear wave speed (SWS), elasticity and viscosity properties of the optic nerve and sclera.

METHODS

Shear wave speeds were measured at three frequencies-100, 150 and 200 Hz-on the optic nerve and sclera tissues for assessing patients with papilledema resulting from idiopathic intracranial hypertension (IIH). The method was evaluated in six papilledema patients and six controls on two separate locations for each participant (i.e., optic nerve and posterior sclera). SWSs of the optic nerve and sclera were analyzed by using a 2-D speed map technique within a circular region of interest (ROI) (i.e., the diameter of the ROI was 1.5 mm × 3.0 mm at the optic nerve and sclera, respectively). Elasticity and viscosity were then analyzed using the wave speed dispersion over the three frequencies.

RESULTS

We measured values of SWS at both locations, optic nerve and sclera, of the right eye and left eye at three different frequencies in IIH patients and controls. The SWS (mean ± standard deviation [m/s]) of the right eye was significantly higher at the sclera in IIH patients compared with controls (i.e., patients vs. controls: 5.91 ± 0.54 vs. 3.86 ± 0.56, p < 0.0001 at 100 Hz), but there was no significant difference at the optic nerve (i.e., patients vs. controls: 3.62 ± 0.39 vs. 3.36 ± 0.35, p = 0.1100 at 100Hz). We observed increased elasticity (kPa) in IIH patients, indicating there are significant differences in elasticity between patients and controls at the optic nerve and sclera (i.e., right eye [patients vs. controls]: 14.42 ± 6.59 vs. 6.5 ± 5.71, p = 0.0065 [optic nerve]; 33.04 ± 10.62 vs. 9.16 ± 7.15, p < 0.0001 [sclera]). Viscosity was also (Pa·s) higher in the sclera and optic nerve of the left eye (i.e., left eye [patient vs. control]: 8.89 ± 4.37 vs. 7.27 ± 5.01, p = 0.3790 (optic nerve); 16.05 ± 10.79 vs. 8.49 ± 6.09, p < 0.0194 [sclera]).

CONCLUSION

This research illustrates the feasibility of using our UVE system to evaluate stiffness of different tissues in the eye non-invasively. It suggests that the viscoelasticity of the posterior sclera is higher than that of the optic nerve. We found that the posterior sclera is stiffer than the optic nerve in patients with papilledema resulting from IIH, making UVE a potential non-invasive technique for assessing papilledema.

Predictive value of liver and spleen stiffness measurement based on two-dimensional shear wave elastography for the portal vein pressure in patients with compensatory viral cirrhosis

Objective

This study aimed to explore the predictive value of liver and spleen stiffness measurement based on two-dimensional shear wave elastography for the portal vein pressure in patients with compensatory viral cirrhosis.

Methods

From January 2017 to August 2019, 107 patients with compensatory viral cirrhosis and 76 patients with viral hepatitis were enrolled as cirrhosis group and hepatitis group, respectively. Patient data were obtained during admission, and this study was a review and analysis of patient data. Liver stiffness measurement (LSM), spleen stiffness measurement (SSM), portal vein diameter and spleen thickness were compared between the two groups, and their diagnostic value for compensatory viral cirrhosis was analyzed. According to the hepatic vein pressure, the cirrhosis group patients were divided into non-hypertensive group (no portal hypertension, hepatic venous pressure gradient (HVPG) < 5 mmHg), mild group (mild portal hypertension, 5 mmHg ≤ HVPG ≤ 10 mmHg) and severe group (clinically significant portal hypertension group, HVPG > 10 mmHg). LSM, SSM, portal vein diameter and spleen thickness of the three groups were compared, and the correlation between SSM and hepatic vein pressure was analyzed.

Results

LSM, SSM, portal vein diameter and spleen thickness in the cirrhosis group were higher than those in hepatitis group (all P < 0.05). The area under the curve (AUC) of combined detection was larger than that of LSM, SSM and spleen thickness detection alone in liver cirrhosis diagnosis (all P < 0.05). LSM, SSM, portal vein diameter and spleen thickness increased with the increase of hepatic vein pressure in patients with liver cirrhosis (all P < 0.05). LSM, SSM, portal vein diameter and spleen thickness were all positively correlated with hepatic vein pressure (P < 0.05). ROC curve showed that AUC of combined detection was greater than that of LSM, SSM, portal vein diameter and spleen thickness alone detection in the diagnosis of clinically significant portal hypertension (all P < 0.05). The increase of LSM, SSM, portal vein diameter and spleen thickness were the influencing factors for hepatic vein pressure rising (all P < 0.05).

Conclusion

There was an increase of LSM and SSM in patients with compensatory viral cirrhosis, which were positively correlated with hepatic venous pressure, and combined index detection has diagnostic and predictive value for the change of portal venous pressure.

Usefulness of two-dimensional shear wave elastography in the assessment of non-alcoholic fatty liver disease in children and adolescents

Two-dimensional shear wave elastography (2D-SWE) evaluates liver stiffness using a non-invasive method, but studies in the paediatric population are rare. This study evaluated the role of 2D-SWE in the diagnosis and severity of paediatric non-alcoholic fatty liver disease (NAFLD). In total, 131 patients with NAFLD and 25 healthy controls were enrolled in this study. The diagnosis and severity of NAFLD were initially assessed using the ultrasound fatty liver index (US-FLI), and all participants underwent 2D-SWE. US-FLI semi-quantitatively measures the severity of NAFLD on a scale of 2-8. The assessment of liver stiffness measurement (LSM) by 2D-SWE is presented in kilopascals (kPa). The NAFLD group was characterised by significantly higher LSM (4.40 ± 0.90 kPa) than the control group (3.76 ± 0.28 kPa) (P < 0.001). 2D-SWE significantly correlated with age, height, weight, body mass index, glucose, aspartate aminotransferase, alanine aminotransferase, high-density lipoprotein cholesterol, US-FLI, and triglyceride-glucose index (P < 0.001). In the receiver operating characteristic curve analysis, the area under the curve of LSM for predicting US-FLI ≥ 2 and ≥ 6 was 0.784 (P < 0.001) and 0.819 (P < 0.001), respectively. In conclusion, we suggest that 2D-SWE can be used as a non-invasive diagnostic tool for diagnosing and assessing the severity of paediatric NAFLD.

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.

Enzyme replacement therapy for children with acid sphingomyelinase deficiency in the real world: A single center experience in Taiwan

Background

Acid sphingomyelinase deficiency (ASMD) is a lysosomal storage disease with multi-systemic involvement, with no disease-modifying treatment available. Olipudase alfa is an investigational enzyme product developed to replace the deficient acid sphingomyelinase in ASMD patients. Several clinical trials have reported promising safety and efficacy results in adult and pediatric patients. However, no data have been reported outside of the clinical trial setting yet. This study aimed to evaluate major outcomes in pediatric chronic ASMD patients receiving olipudase alfa in the real-world setting.

Materials and methods

Two children with type A/B (chronic neuropathic) ASMD have received olipudase alfa treatment since May 2021. Clinical parameters, including height, weight, complete blood count, liver function tests, lipid profiles, biomarkers, abdominal ultrasonography with shear wave elastography, chest computed tomography, nerve conduction studies, neurodevelopmental evaluations, and six-minute walk tests, were checked at baseline and every three to six months in the first year of enzyme replacement therapy (ERT) to assess its efficacy and safety.

Results

The two patients in our study started olipudase alfa treatment at the age of 5 years and 8 months and 2 years and 6 months. During the first year of treatment, both patients saw a reduction in their hepatic and splenic volumes as well as liver stiffness. Height z-score, weight z-score, lipid profiles, biomarker levels, interstitial lung disease scores, and bone mineral densities also improved over time. The six-minute walk test showed a gradual increase in walking distance in both patients. There were no obvious improvements or deterioration in neurocognitive function and peripheral nerve conduction velocities after treatment. No severe infusion-associated reactions were noted during the first year of treatment. One patient had two episodes of transient but significantly elevated liver enzymes during the dose-escalation phase. The patient was asymptomatic, and the impaired liver function resolved spontaneously within two weeks.

Conclusion

Our results provide real-world experience that olipudase alfa is safe and effective in improving major systemic clinical outcomes for pediatric chronic ASMD patients. Monitoring of liver stiffness by shear wave elastography is a noninvasive procedure that can monitor treatment efficacy during ERT.

Use of a combined transient elastography and biochemical strategy to determine liver fibrosis in pediatric intestinal failure

BACKGROUND & AIMS

Non-invasive monitoring of intestinal failure (IF) associated liver disease is an ongoing challenge in children with IF. Our objective was to develop a combined algorithm of clinical, transient elastography (TE) and biochemical parameters to identify liver fibrosis in this population.

METHODS

A retrospective cohort study of IF patients followed by our intestinal rehabilitation program between November 2015 to October 2019. Patients with a liver biopsy and TE were included. Demographic and liver function tests were collected. Fibrosis on liver biopsies was graded using the modified Scheuer score. Decision tree based algorithms classified low (F0-F1) versus high (F2-F4) fibrosis scores based on a combination of TE, biochemical and demographic parameters, using 6-fold classification error, sensitivity and specificity cross-validation (CV) scores.

RESULTS

42 patients (74% male, median age 7.6 (4.6; 42.7) months) were evaluated. Median length of PN therapy was 182 (121; 556) days. High fibrosis was present in 40.5% with a median TE of 12.1 (6.7; 12.9) kPa in high fibrosis children. An algorithm, based on cut-off values for TE of 11.3 kPa and AST of 40 U/L, and grouping of the underlying etiology resulted in a correct classification of 88.1% of the pathology scores; with sensitivity 0.82 (95% CI 0.57; 0.96), specificity 0.92 (95% CI 0.74; 0.99), positive predictive value 0.88 (95% CI 0.64; 0.96) and negative predictive value 0.88 (95% CI 0.73; 0.96). The CV classification error was 28.6%, CV sensitivity 72.2% and CV specificity 75.5%.

CONCLUSIONS

This algorithm shows promising results that could simplify non-invasive monitoring of liver fibrosis in children with IF. Validation in additional IF cohorts is needed.

Liver Disease Assessment in Children with Fontan and Glenn Surgeries for Univentricular Hearts—The Role of Elastography and Biochemical Fibrosis Markers

Background: Children born with single-ventricle hearts require surgery in order to survive. Liver fibrosis is a known complication of Fontan surgery for univentricular hearts. Methods: In this study on 13 post-Fontan and 21 post-Glenn patients, we used elastography (shearwave and transient elastography) as well as serum biochemical fibrosis markers to evaluate the degree of liver fibrosis in comparison to 32 controls. Results: The mean Emedian and Vmedian values determined by shear wave elastography in the Fontan Group were significantly higher than the controls (4.85 kPa vs. 3.91 kPa and 1.25 m/s vs. 1.12 m/s, respectively). Fontan patients had significantly increased Fibrotest, Actitest, AST-to-Platelet Ratio index, ALT and GammaGT levels compared to controls. For post-Glenn patients, the mean Emedian and Vmedian values were similar to healthy controls, whereas the Fibrotest, Actitest and AST-to-Platelet Ratio index were significantly increased. Using transient elastography, we found significantly higher values for Emedian and Vmedian in Fontan patients compared to Glenn patients. Conclusions: Elastography and biochemical fibrosis markers are valuable non-invasive tools for screening and monitoring liver fibrosis in patients with Fontan and Glenn interventions.

Ultrasound elastography in children - nice to have for scientific studies or arrived in clinical routine?

Ultrasound elastography (USE) is a modality that in addition to fundamental B-mode, Doppler, and contrast-enhanced sonography is suitable to make qualitative and quantitative statements about the stiffness of tissues. Introduced more than 20 years ago in adults, USE becomes now a diagnostic tool also in children. The aim of this paper is to describe current available techniques for USE in children. The significance for routine use in children is shown, and further interesting applications are reported.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

IMPACT

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

Noninvasive Pediatric Liver Fibrosis Measurement: Two-Dimensional Shear Wave Elastography Compared With Transient Elastography

OBJECTIVES

Although transient elastography (TE) is the primary noninvasive method for assessing liver fibrosis, its use remains to be validated in children. This study aims to evaluate the agreement between two-dimensional ultrasound shear wave elastography (2D-SWE) and TE to assess pediatric liver stiffness method.

METHODS

During the 18-month study, we prospectively included 101 consecutive children (median age: 8.5 years, range: 1 month to 17 years) who required TE for medical reasons, and in whom 2D-SWE measurement was performed within a 3-month follow-up during a routine ultrasound. Liver elasticity values were classified according to the Metavir score using published pediatric norms for TE and according to the manufacturer's reference values for 2D-SWE. The Spearman's correlation coefficient was used to assess the relationship between the elasticity measured by the two techniques. Concordance was described by the Bland-Altman method.

RESULTS

A strong correlation (rho = 0.70, p < 0.001) was found between 2D-SWE and TE for the elasticity measures. The strength of correlation was higher among patients older than 6 years (rho = 0.79, p < 0.001). Concordance between liver fibrosis stages assessed by these techniques was moderate [weighted kappa = 0.46, (95% CI: 0.35-0.57)]. When considering stages over F2, 2D-SWE diagnostic performances showed a sensitivity of 85% (95% CI: 74-92) and a specificity of 57% (95% CI: 42-70) compared with TE.

CONCLUSION

Measurements of the liver stiffness using 2D-SWE and TE are strongly correlated. The moderate concordance between these techniques for assessing the liver fibrosis stage provides evidence against alternating between these methods during follow-up of patients with the chronic liver diseases.

Pediatric percentiles for transient elastography measurements - effects of age, sex, weight status and pubertal stage

BACKGROUND AND AIMS

Transient Elastography is a non-invasive, cost-efficient, non-ionizing, observer-independent and reliable method to detect liver fibrosis using Liver Stiffness Measurement (LSM) and the degree of fat accumulation in the liver using Controlled Attenuation Parameter (CAP). This study aims to derive reference values for both measures from healthy children and adolescents. Further, we aim to assess the potential influence of age, sex, puberty, and BMI-SDS on CAP and LSM.

METHODS

Within the LIFE Child study, amongst others, anthropometric data and pubertal status were assessed. Transient Elastography (TE) was performed using the FibroScan^® device in a population-based cohort at 982 study visits of 482 healthy children aged between 10 and 18 years. Percentiles for LSM and CAP were estimated, and the effects of age, sex, puberty and weight status were assessed through hierarchical regression models.

RESULTS

There was a strong age dependency for LSM with higher values for older children, most pronounced in the upper percentiles in boys. Contrarily, CAP was relatively stable across the age span without considerable difference between boys and girls. We found a significant positive correlation between BMI-SDS and both CAP and LSM for BMI-SDS >1.28. For BMI-SDS < 1.28, the association was also positive but reached statistical significance only for CAP. Further, the association between BMI-SDS and CAP was significantly stronger in younger than in older children. There was no association between pubertal status and CAP. For LSM, we found that children with a high BMI-SDS but not children with normal weight had significantly higher LSM values in Tanner stage 4.

CONCLUSIONS

Age, sex, pubertal status and weight status should be considered when interpreting LSM and CAP in pediatric patients to facilitate and improve early detection of abnormal liver function, which is associated with common pathologies, such as NAFLD.

A tailored passive driver for liver MRE in pediatric patients

Objectives

Magnetic resonance elastography (MRE) is increasingly used in the pediatric population for diagnosis and staging of liver fibrosis. However, the MR-compatible driver and sequences are usually those used for adult patients. Our feasibility study aimed to adapt the standardized adult MRE passive driver and vibrational parameters to a pediatric population.

Methods

We designed an elliptic passive driver shaped on a torus equipped with an elastic membrane and adapted to children's morphologies. As a first step, eight children (aged 8-18 years) were enrolled in a prospective pilot study aiming to determine the threshold vibrational amplitude for MRE using a custom passive driver, based on phase aliasing assessment and the occurrence of signal void artifacts on magnitude MR images. In the second step, the practicality and the consistency of the custom driver were assessed in a further 11 pediatric patients (aged 7-18 years). In the third step, we compared our custom driver vs. the commercial driver on six adult volunteers, in terms of the reliable region of interest area within the acquired MRE slices, the shear wave maps' quality, and measured stiffness values obtained.

Results

Based on pediatric patient data, the threshold vibrational amplitude expressed as percentage of maximum output was found to be 0.4 and 1.1 times the body weight (kg) at 40 and 60 Hz frequencies, respectively. In comparison to the commercial passive driver, the custom driver improved threefold the contact with the body surface, also enabling a more comfortable examination as self-assessed by the volunteers.

Conclusions

Our custom driver was more comfortable for the volunteers and was able to generate more homogenous shear waves, yielding larger usable hepatic area, and more reliable stiffness values.

Recent advances in the use of ultrasound and related techniques in diagnosing and predicting outcomes in biliary atresia

PURPOSE OF REVIEW

Biliary atresia (BA) is the leading cause of chronic liver disease and the most common indication for pediatric liver transplantation. The use of ultrasound (US) and related techniques continues to evolve to help diagnose BA as well as potentially to help predict outcomes after treatment with the Kasai portoenterostomy (KP).

RECENT FINDINGS

There are no US findings that are definitive for BA; however, signs which are consistent with BA include gallbladder abnormalities, the triangular cord sign, presence of hepatic subcapsular flow, and hilar lymphadenopathy. Elastography techniques to measure liver stiffness may also increase the diagnostic accuracy of detecting BA, particularly in older infants or without other US findings. In addition, both US and elastography are still being studied as potential methods to predict outcomes after KP such as the development of portal hypertension and the need for liver transplant.

SUMMARY

US findings in the diagnosis of BA are well characterized. Future studies will help determine the utility of elastography in diagnosing BA, as well as both US and elastography in monitoring and predicting disease outcomes after KP.

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.

Feasibility and Reliability of Two-Dimensional Shear-Wave Elastography of the Liver of Clinically Healthy Cats

Given the broad overlap of normal and abnormal liver tissue in the subjective evaluation of the liver in conventional B-mode ultrasonography, there is a need for a non-invasive and quantitative method for the diagnosis of liver disease. Novel two-dimensional shear-wave elastography (2-D SWE) can measure tissue stiffness by propagation of the shear wave induced using acoustic radiation force impulse in real time. To the best of our knowledge, two-dimensional shear-wave measurement of the liver in cats has not been reported to date. This study assessed the feasibility, reliability, normal values, and related influencing factors of 2-D SWE for assessment of the feline liver without anesthesia and breath-holding. Two-dimensional shear-wave ultrasonography was performed by two evaluators at the right and left sides of the liver. Twenty-nine client-owned clinically healthy adult cats were included. The means and standard deviations for the shear-wave speed and stiffness in the right liver were 1.52 ± 0.13 m/s and 6.94 ± 1.26 kPa, respectively, and those for the left liver were 1.61 ± 0.15 m/s and 7.90 ± 1.47 kPa, respectively. Shear-wave speed (P = 0.005) and stiffness (P = 0.002) were significantly lower in the right liver when compared to the left. The intraclass correlation value for liver stiffness was 0.835 and 0.901 for the right and left liver, respectively, indicating high interobserver agreement. Age, weight, body condition score (BCS), gabapentin administration, and measurement depths were not significantly correlated with liver stiffness or elastography measurements (P > 0.05). Our findings suggest that 2-D SWE measurements of the liver are not influenced significantly by age, weight, or BCS and can be reliably performed without anesthesia and breath-holding in cats. The values determined here can help form the basis for reference elastography values for evaluation of the feline liver.