Shear Wave Elastography In Children Research Articles

Diastolic Myocardial Stiffness Assessed by Shear Wave Elastography in Children With a Fontan Circulation

Diastolic Myocardial Stiffness Assessed by Shear Wave Elastography in Children With a Fontan Circulation

Evaluation of Hepatosteatosis-Induced Increase in Fibrosity by Two-Dimensional Shear Wave Elastography in Children with Obesity and Comparison with Healthy Peers.

The increase in the prevalence of obesity, nonalcoholic fatty liver disease (NAFLD), and related comorbidities in children creates a social and financial burden. In our study, we aimed to evaluate liver findings together with anthropometric and laboratory data with twodimensional shear wave elastography (2D-SWE), one of the SWE types, which is a noninvasive method for assessing tissue stiffness in children with obesity, and to obtain quantitative data that can be used in early diagnosis and follow-up. In our single-center, observational cross-sectional study, liver gray scale findings, 2D-SWE findings, anthropometric measurements, and laboratory values of 48 children with obesity and 50 healthy children aged between 5 and 18 years, both between groups and in prepubertal and pubertal subgroups, are compared. A significant difference was found in the liver stiffness indicator kilopascal (kPA) values and between aspartate aminotransferase values in the prepubertal period and alanine aminotransferase values in the pubertal period (P < .001). No significant difference was found between insulin, HOMA-IR, waist circumference, waist/height ratio, and kPA. Two-dimensional shear wave elastography can be easily applied in the pediatric population as a practical, noninvasive, reproducible, and highly compatible technique. In this regard, 2D-SWE may be useful in the early diagnosis and follow-up of hepatosteatosis and fibrosis in children with obesity and NAFLD-risky cases.

Shear Wave Elastography in Children with Portal Vein Thrombosis is not a Sensitive Predictor of Upper Gastrointestinal Bleeding: a Pilot Study

Shear Wave Elastography in Children with Portal Vein Thrombosis is not a Sensitive Predictor of Upper Gastrointestinal Bleeding: a Pilot Study

Evaluation of Gastrocnemius Spasticity With Shear-Wave Elastography in Children with Cerebral Palsy after Botulinum Toxin Injection: Defining A Proper Position for Measurement

Aim: Cerebral Palsy (CP) is the most common neuromuscular disorder in children and it is characterized by a dysfunction in movement and posture. Botulinum toxin injection is a treatment method used for muscle spasticity in patients with CP. Elastography is a new method which is used for measuring muscle stiffness. This study aims to evaluate the gastrocnemius muscle stiffness in cerebral palsy patients before and after botulinum toxin injection by using the elastography method and contribute to the establishment of a treatment algorithm with a proper position for measurement.Materials and Method: The participants of this study were chosen from the patients of our hospital’s orthopaedics and traumatology department. Among the patients on whom botulinum injection to gastrocnemius muscle was planned, 30 patients were randomly selected. Elastography of both gastrocnemius muscles were taken before the injection of botulinum toxin, in the third week and third month after the injection. Simultaneously with the elastography, Modified Ashworth Scale (MAS) values were noted. In hemiparetic patients, contralateral legs were taken as the control group.Results: The elastographic values of the medial head of gastrocnemius when the knee is in extension and ankle in passive dorsiflexion, were found to be statistically significantly related (p&amp;lt;0.05) to the MAS values before botulinum toxin injection, third week and third month post-injection.Conclusion: Stiffness due to spasticity in gastrocnemius muscle in CP patients was demonstrated through elastographic evaluation. A correlation was found between clinical MAS values. The most proper position was in which the knee is fully extended and the ankle is passively dorsiflexed. Elastographic measurements may be able to be used in these patients as a method of diagnosis in the future and it will help to assess the effectiveness of the treatment after the injection of botulinum toxin.

Factors affecting passive muscle stiffness through shear wave elastography in children with spastic cerebral palsy

Factors affecting passive muscle stiffness through shear wave elastography in children with spastic cerebral palsy

Analysis of Thyroid Gland Problems with Shear Wave Elastography in Children with Celiac Disease.

The rate of autoimmune thyroiditis in children with celiac disease (CD) is high relative to the normal population. Since the majority of these patients are also euthyroid, thyroid imaging methods are gaining significance in diagnosis and follow-up. This study examines the effectiveness of thyroid ultrasonography (US) and thyroid shear wave elastography (SWE) in diagnosing thyroid disease in children with CD. This cross-sectional controlled study analyzed thyroid US, SWE, serum thyroid function tests, and thyroid autoimmune antibodies of 106 CD patients and 103 control patients without CD. An Aplio 500 ultrasound device with a linear array transducer and elastography software was used for thyroid US and SWE measurement of all patients. Right lobe thyroid volume, left lobe thyroid volume, total thyroid volume, thyroid mean elasticity (m/s), right lobe elasticity (kPa), left lobe elasticity (kPa), and mean thyroid elasticity (kPa) levels of the CD group were higher than those of the control group (p < 0.001). The relationships between thyroid US and thyroid mean elasticity (m/s), thyroid mean elasticity (kPa), anti-thyroid peroxidase antibody, and thyroid-stimulating hormone were positive and moderate, respectively (r = 0.612, 0.612, 0.636, and 0.565, respectively; p < 0.001). In this study, SWE findings were compatible with laboratory findings, as they constituted a sensitive and useful method in the diagnosis and follow-up of autoimmune thyroid disease in children with CD.

Pancreatic shear wave elastography in children with type 1 diabetes: relation to diabetes duration, glycemic indices, fasting C-peptide and diabetic complications

BackgroundLittle is known about changes in the pancreas as the course of type 1 diabetes progresses. Recently, shear wave elastography (SWE) emerged as a tool for assessing pancreatic stiffness in chronic pancreatitis and pancreatic cancer with a few studies assessing it in diabetes.ObjectiveTo compare pancreatic SWE in children with recent-onset and long-standing type 1 diabetes to healthy controls and to correlate it with diabetes duration, glycated hemoglobin (HbA1C), functional B cell reserve (fasting C-peptide) and diabetic complications.Materials and methodsFifty children with type 1 diabetes (25 with recent-onset and 25 with long-standing type 1 diabetes) and 50 controls were enrolled. Diabetes duration, insulin therapy, fundoscopic examination of the eyes and the neuropathy disability score were assessed. Fasting C-peptide, lipids, HbA1C and urinary albumin-creatinine ratio were measured. Pancreatic SWE was measured using the General Electric Logiq P9 ultrasound system.ResultsThe mean SWE of the studied children with recent-onset type 1 diabetes was 4.81±0.62 kilopascals (Kpa), those with long-standing type 1 diabetes was 7.10±1.56Kpa and for controls was 5.57±0.27 Kpa (P<0.001). SWE was positively correlated to diabetes duration (P<0.001) and negatively correlated to fasting C-peptide (P<0.001). Regarding diabetes complications, SWE was positively correlated to frequency of severe hypoglycemia (P=0.005), HbA1C (P=0.03), low-density lipoproteins (P<0.001) and cholesterol (P<0.001) and significantly related to diabetic neuropathy (P=0.04) and nephropathy (P=0.05). Diabetes duration, fasting C-peptide, HbA1C and frequency of severe hypoglycemia were the significant independent variables related to SWE increase by multivariable regression analysis.ConclusionPancreatic SWE changes significantly with duration of type 1 diabetes, being lowest in those with recent-onset type 1 diabetes and highest in those with long-standing type 1 diabetes, particularly those with diabetic nephropathy and neuropathy.

Shear-wave elastography for the assessment of testicular involvement of hematologic malignancies in children and young adults: a feasibility study.

PurposeThis study aimed to assess the feasibility of shear-wave elastography (SWE) for assessing the testicular involvement of hematologic malignancies in children and young adults.MethodsEight patients (mean age, 11.0 years; range, 0.8 to 20 years) with biopsy-confirmed testicular involvement of hematologic malignancy between January 2018 and December 2020 were retrospectively evaluated. Multiparametric ultrasound examinations, including grayscale, color Doppler ultrasonography (CDUS), and SWE, were performed. Stiffness was measured in the involved testicular area and contralateral normal parenchyma. If there was bilateral testicular involvement, the stiffness of the involved area and the adjacent normal echoic parenchyma was measured on one testis. The Mann-Whitney U test was used to compare stiffness values.ResultsOn grayscale, the testicular lesions were noted as a solitary mass in one patient, multiple lesions in four patients, and diffuse involvement in three patients. On CDUS and SWE, all patients demonstrated increased vascularity, and the stiffness of the involved area was higher than the values of normal parenchyma (the involved area vs. normal parenchyma, 11.6 kPa [3.9-20.2 kPa] vs. 2.9 kPa [1.1-3.7 kPa], P=0.003). The ratio of stiffness between the involved area and normal parenchyma was 3.4, ranging from 1.9 to 5.1. One patient showed decreased stiffness on follow-up SWE after treatment (affected testis vs. normal testis: initial, 13.8 vs. 3.2 kPa; 1 year later, 2.2 vs. 2.4 kPa).ConclusionIncreased testicular stiffness on SWE in children and young adults with hematologic malignancies suggests the possibility of testicular involvement.

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

Ultrasound elastography has been suggested for assessing organ fibrosis. 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. 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. 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. 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.

Shear wave elastography of temporomandibular joint disc and masseter muscle stiffness in healthy children and adolescents: a preliminary study.

Shear wave elastography (SWE) are promising techniques in diagnosing temporomandibular joint (TMJ) disc and masseter muscle disorders. To investigate normative stiffness values of the TMJ disc and masseter muscle by SWE in children and adolescents. This prospective study evaluated 123 TMJ discs and masseter muscles in 123 subjects. The stiffnesses of anterior, middle, and posterior parts of the disc and the masseter muscle were measured. This study investigated differences in mean elasticity [kilopascal (kPa)] and velocity [metre/second (m/s)] values of the different disc parts and the masseter muscle in closed and open mouth positions, and the correlations of these SWE values with age, body mass index (BMI), height, and weight of the subjects. The median stiffness disc values of all participants were 28.7kPa (elasticity) and 3.07m/s (velocity) for the anterior, 29.10kPa and 3.07m/s for the middle, and 23.2kPa and 2.77m/s for the posterior parts. Posterior stiffness was significantly lower than other body regions in all subjects and across all age groups. The mean stiffness values of the muscle were 16.96 ± 9.01kPa and 2.33 ± 1.2m/s for the closed mouth, and 28.7 ± 10.2kPa and 3.23 ± 1.32m/s for the open mouth. The stiffness of the TMJ disc was significantly lower in the posterior part than in the anterior or middle parts. The mean stiffness was significantly higher in the open mouth than in the closed mouth position. Neither elasticity nor velocity were associated with age, height, weight, or BMI.

Diagnostic value of real-time shear wave elastography in children with chronic kidney disease.

To evaluate the diagnostic value of real-time shear wave elastography (SWE) in children with chronic kidney disease (CKD). Children with CKD diagnosed by the ultrasound-guided biopsy between January 2018 and May 2019 were enrolled as the case group. Age- and sex- matched healthy children were selected as the control group. The Young's Modulus (YM) of the renal cortex was measured by SWE after the traditional ultrasound examination. Variance analysis was performed to compare the values of YM between the two groups. Receiver operating characteristic curve (ROC) analysis was used to compare the values of YM, and explore the cut-offs of the YM. In the case group (n = 60, 45% male, mean age of 9.2 years), the kidney YM modulus on the left side (16.8±4.8 kPa vs. 8.3±2.1 kPa) and the right side (16.0±4.7 kPa vs. 8.3±2.4 kPa) were both higher than the control group (all P values < 0.001). With the progress of CKD, the YM value of the left and right kidneys gradually increased. ROC analysis showed that when the left and right kidney YM value was 11.7 kPa and 11.0 kPa, the diagnostic sensitivity and specificity were the highest (left: respectively 93.3% and 95.0%; right: respectively 93.3 % and 91.7%). The increase of YM in CKD is related to the progression of renal dysfunction which may provide a new method for early diagnosis of CKD, dynamic monitoring of disease progression, and evaluation of curative effect and prognosis.

Normative values of pancreas stiffness by shear wave elastography in healthy children and adolescents.

To define normal pancreas elasticity and velocity values with shear wave elastography (SWE) in healthy children and assess associations with gender, age, and body mass index (BMI). This prospective study included a total of 100 cases (male: 50; female: 50), aged 3-17years. Preschool, school, and adolescent periods of 3-6years (n = 27), 7-12years (n = 30), and 13-17years (n = 43), respectively, were created in addition to two groups representing prepubertal and postpubertal periods of 3-10years (n = 50) and 11-18years (n = 50), respectively. Demographic data regarding the gender, age, height, body weight, and BMI were recorded. Pancreatic head, corpus, and tail SWE measurements were performed with a convex transducer (3.5-5MHz). Correlations and comparisons were made for stiffness values between groups. Statistical analyses used Mann-Whitney U, Kruskal-Wallis, and Spearman's correlation tests. Medians (25-75th percentage) of age and BMI were 7 (4.25-10) years and 15 (13-17) years and 17.47 (14.94-19.23) kg/m2 and 21.22 (17.41-24) kg/m2 in the two age groups, respectively. The median (interquartile range) elasticity and velocity values for the head, corpus, and tail sections of the pancreas were measured as 9.35 (2.9) kPa and 1.76 (0.26) m/s; 9.3 (2.5) kPa and 1.74 (0.21) m/s; and 8.75 (2) kPa and 1.69 (0.15) m/s, respectively. No significant differences were identified for stiffness values between gender and pancreatic section. Pancreatic stiffness values were significantly different among two (p = 0.001) and three (p = 0.028) age groups, and presented mild positive correlations with age (r: 0.23, p: 0.002), height (r: 0.18, p: 0.01), body weight (r: 0.38, p: 0.003), and BMI (r: 0.37, p: 0.045). Normal elasticity and velocity values were defined for the pancreas with SWE in children. Pancreatic stiffness does not significantly change among pancreas parts, but it increases with the transition from childhood to adolescence.

Frequency of technical success of two-dimensional ultrasound shear wave elastography in a large pediatric and young adult cohort: a clinical effectiveness study.

There is a paucity of available literature describing the frequency of technical success of liver two-dimensional (2-D) ultrasound (US) shear wave elastography (SWE) in children and young adults. To determine the frequency of technical success of liver 2-D ultrasound (US) SWE in children and young adults based on the interquartile range (IQR)/median of 10 shear wave speed (SWS) measurements. Clinical 2-D US SWE exams performed between February 2016 and March 2018 were retrospectively identified. Patient age and gender, median/mean liver stiffness (10 SWS measurements), IQR/median, abdominal wall thickness, body mass index (BMI) and serum alanine aminotransferase (ALT) were documented. The number of technically inadequate exams was calculated using three methods: 1) IQR/median >0.3, 2) IQR/median >95th percentile for our study population and 3) statistical outlier identification using the Tukey method. The effect of age, gender, median SWS, abdominal wall thickness, BMI, US transducer and ALT on measurement variability (IQR/median) was assessed using multivariable linear regression. During the study period, 573 exams were performed. Mean age was 12.6±7.1years; 274 (47.8%) exams were in male patients. Average median liver stiffness was 1.75±0.47m/s. Based on Methods 1, 2 and 3, 29/573 (5.1%), 28/573 (4.9%, IQR/median cutoff value=0.303) and 30/573 (5.2%) exams were technically inadequate. Predictors of IQR/median included age (P=0.03), abdominal wall thickness (P=0.003), median SWS (P<0.0001) and transducer (P<0.0001). Approximately 95% of liver 2-D US SWE exams are technically successful based on IQR/median in children and young adults.

Performance of two--dimensional ultrasound shear wave elastography: reference values of normal liver stiffness in children.

Two-dimensional (2-D) shear wave elastography is a new sonographic elastography method for noninvasive measurement of liver stiffness. The aim of this study was to establish reference values of normal liver stiffness on 2-D shear wave elastography in children. Two-dimensional shear wave elastography values were measured in 202 children with no liver disease from the neonatal period to puberty, who were divided into 4 age groups: newborns and infants, preschoolers, elementary school children and adolescents. We investigated the effects of age, depth of elastography measurement, transducer, number of measurements per child, liver size and Doppler parameters of hepatic blood flow on liver elasticity values. The mean normal liver elasticity value in the study population was: 4.29±0.59 kilopascals (kPa). In neonates and infants, mean liver elasticity value was 4.63 (± 0.6) kPa, in preschoolers and elementary school children, 4.05 (± 0.57) kPa and 4.15 (± 0.52) kPa, respectively, and in adolescents, 4.39 (± 0.55) kPa. Values in neonates and infants as well as adolescents were significantly higher than in preschoolers and elementary school children (Kruskal-Wallis, P<0.001; Mann-Whitney U tests, P<0.05). There was no significant association between liver elasticity values and size of the right lobe or Doppler parameters of hepatic blood flow. Different depths and the number of elastography measurements had no effect on liver elasticity values. Two-dimensional shear wave elastography is achievable in a wide range of age in children. We established the reference values of normal liver stiffness on 2-D shear wave elastography in children.

Is there a correlation between Reimers’ hip migration percentage and stiffness of hip muscles measured by shear wave elastography in children with cerebral palsy?

The Reimers’ hip migration percentage (MP) is commonly used to examine the amount of lateral displacement of the femoral head in children with cerebral palsy (CP). Abnormal forces of the hip flexor and adductor muscles are proposed as the contributing factors of hip dislocation in children with CP. Shear wave elastography (SWE) is an ultrasound based technique which provides a quantitative measurement of the tissue stiffness. The aim of this study was to assess the correlation between the MP and the stiffness of the hip muscles. This prospective study included 50 hips of 25 children with spastic CP. All muscles were evaluated in longitudinal plane by SWE with a linear transducer that enables scanning with a frequency ranging of 9 − 4 MHz. The stiffness of the gluteus medius and maximus, adductor magnus and iliopsoas muscles was measured by SWE. The MP was measured on anteroposterior radiographs. The correlation between the Reimer's MP and the stiffness of hip flexors and adductors were analyzed. The correlations among the stiffness of the hip flexor-extensor and adductor-abductor muscle groups were also assessed. There is a moderate positive correlation between MP and the stiffness of hip flexor muscles ( r = 0.70, P < 0.05). There is a moderate positive correlation between MP and the stiffness of hip adductor muscles ( r = 0.71, P < 0.05). The correlation between the stiffness of flexor and extensors is weak ( r = 0.10, P ≥0.05). There is a weak correlation between the stiffness of abductor and adductor muscles ( r = 0.32, P ≥0.05). We suggest that increased flexor and adductor muscle stiffness would be a potential high risk factor of hip dislocation in children with CP. Measuring muscle stiffness may provide helpful information during follow-up of these patients.

Is there a correlation between Reimers’ hip migration percentage and stiffness of hip muscles measured by shear wave elastography in children with cerebral palsy?

The Reimers’ hip migration percentage (MP) is commonly used to examine the amount of lateral displacement of the femoral head in children with cerebral palsy (CP). Abnormal forces of the hip flexor and adductor muscles are proposed as the contributing factors of hip dislocation in children with CP. Shear wave elastography (SWE) is an ultrasound based technique which provides a quantitative measurement of the tissue stiffness. The aim of this study was to assess the correlation between the MP and the stiffness of the hip muscles. This prospective study included 50 hips of 25 children with spastic CP. All muscles were evaluated in longitudinal plane by SWE with a linear transducer that enables scanning with a frequency ranging of 9 − 4 MHz. The stiffness of the gluteus medius and maximus, adductor magnus and iliopsoas muscles was measured by SWE. The MP was measured on anteroposterior radiographs. The correlation between the Reimer's MP and the stiffness of hip flexors and adductors were analyzed. The correlations among the stiffness of the hip flexor-extensor and adductor-abductor muscle groups were also assessed. There is a moderate positive correlation between MP and the stiffness of hip flexor muscles ( r = 0.70, P < 0.05). There is a moderate positive correlation between MP and the stiffness of hip adductor muscles ( r = 0.71, P < 0.05). The correlation between the stiffness of flexor and extensors is weak ( r = 0.10, P ≥0.05). There is a weak correlation between the stiffness of abductor and adductor muscles ( r = 0.32, P ≥0.05). We suggest that increased flexor and adductor muscle stiffness would be a potential high risk factor of hip dislocation in children with CP. Measuring muscle stiffness may provide helpful information during follow-up of these patients.

Quantitative Assessment of Thyroid, Submandibular, and Parotid Glands Elasticity With Shear-Wave Elastography in Children

Tissue elasticity is becoming a more commonly used parameter in evaluation of parenchyma in inflammatory diseases. Considering the changes in the thyroid and salivary glands with adolescence, determination of mean elasticity ranges with a function of age is necessary to apply ultrasound elastography more widely in the pediatric population.The thyroid, submandibular, and parotid glands of 127 healthy volunteers (66 males, 61 females; mean age = 10.3 ± 3.9 years; range = 3-17 years) were evaluated with shear-wave elastography.The mean elasticity values for the thyroid, submandibular, and parotid glands were 14.6 ± 3.3, 11.8 ± 2.2, and 11.8 ± 2.6 kPa, respectively. There was a significant positive correlation between age and elasticity of the thyroid, submandibular, and parotid glands. There was a significant correlation between age and elasticity value of the thyroid gland adjusted for weight and height.This study provided the baseline quantitative elasticity measures of thyroid, submandibular, and parotid glands, which would be a reference for upcoming studies. In addition, an increase in elasticity value in thyroid gland as a function of age independent of change in weight and height was demonstrated.

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

PurposeThe 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.MethodsA 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.ResultsA 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.ConclusionUtilization 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.

Hepatic shear wave elastography in children under free-breathing and breath-hold conditions.

To compare hepatic 2D shear wave elastography (2D SWE) in children between free-breathing and breath-hold conditions, in terms of measurement agreement and time expenditure. A cohort of 57 children (12.7±4.3 years) who underwent standardized 2D SWE between May and October 2015 were retrospectively evaluated. Liver elastograms were obtained under free-breathing and breath-hold conditions and time expenditure was measured. Median stiffness, interquartile range (IQR), and IQR/median ratio were calculated based on 12, six, and three elastograms. Results were compared using Pearson correlation coefficient, intraclass correlation coefficient (ICC), Bland-Altman analysis, and Student's t. Median liver stiffness under free-breathing and breath-hold conditions correlated strongly (7.22±4.5kPa vs. 7.21±4.11kPa; r=0.97, P<0.001). Time to acquire 12 elastograms with free-breathing was lower than that with breath-holding (79.3±32.5sec vs. 143.7±51.8sec, P<0.001). Results for median liver stiffness based of 12, six, and three elastograms demonstrated very high agreement for free-breathing (ICC 0.993) and for breath-hold conditions (ICC 0.994). Hepatic 2D SWE performed with free-breathing yields results similar to the breath-hold condition. With a substantially lower time requirement, which can be further reduced by lowering the number of elastograms, the free-breathing technique may be suitable for infants and less cooperative children not capable of breath-holding. • Hepatic 2D SWE performed with free-breathing yields results similar to breath-hold condition. • Benefit of the free-breathing approach is the substantially lower time requirement. • Lowering the number of elastograms can further reduce time expenditure. • Free-breathing 2D SWE is suitable in children with suspected liver disease.

Shear Wave Elastography in Children

Most recently the update on the 2013 published European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) Guidelines and Recommendations on the clinical use of elastography have been published focusing on the assessment of diffuse liver disease (1, 2). The first part of the long version of these EFSUMB Guidelines deals with the basic principles of elastography including the reasons why ultrasound can be used to make elastograms. Transient elastography (TE) is explained as shear wave elastometry by measurement of the speed of a shear wave that has been generated using a surface impulse. Point shear wave elastography (pSWE) is explained as shear wave elastometry at a location by measurement of the speed of a shear wave generated using acoustic radiation force. Multidimensional shear-wave elastography (2D-SWE, 3D-SWE) is described as quantitative SWE imaging (and elastometry) by measuring the speed of shear waves generated using acoustic radiation force. Acoustic radiation force impulse (ARFI) imaging is discussed as well (1, 2). Guidance is provided on optimization of scanning technique, image display, image interpretation, reporting of data and some of the known image artefacts. The second and clinical part provides clinical information about the practical use of elastography equipment and interpretation of results in the assessment of different etiologies of diffuse liver disease including normal values and reliability indices (1-4). Comparative little is known about pediatric patients. Data regarding the pediatric population with biliary atresia suggest that liver (and spleen) elastography could be a valuable tool to predict outcomes before surgery, and might be used after the Kasai operation to monitor liver disease and portal hypertension [(5)]. Many other indications have been shown of value in daily practice but comparative studies are lacking. Here we present the current knowledge and our own data on the use of elastography in pediatric patients including the use of strain elastography (SE) and strain-rate imaging (quasi-static strain imaging). Future perspectives of this promising method are discussed as well. 1. Dietrich CF, Bamber J, Berzigotti A, Bota S, Cantisani V, Castera L, Cosgrove D, et al. EFSUMB Guidelines and Recommendations on the Clinical Use of Liver Ultrasound Elastography, Update 2017 (Long Version). Ultraschall Med 2017. 2. Dietrich CF, Bamber J, Berzigotti A, Bota S, Cantisani V, Castera L, Cosgrove D, et al. EFSUMB Guidelines and Recommendations on the Clinical Use of Liver Ultrasound Elastography, Update 2017 (Short Version). Ultraschall Med 2017. 3. Dong Y, Sirli R, Ferraioli G, Sporea I, Chiorean L, Cui X, Fan M, et al. Shear wave elastography of the liver - review on normal values. Z Gastroenterol 2017;55:153-166. 4. Dietrich CF, Dong Y. Shear wave elastography with a new reliability indicator. J Ultrason 2016;16:281-287. 5. Colecchia A, Di Biase AR, Scaioli E, Predieri B, Iughetti L, Reggiani ML, Montrone L, et al. Non-invasive methods can predict oesophageal varices in patients with biliary atresia after a Kasai procedure. Dig Liver Dis 2011;43:659-663.