Point Shear Wave Elastography Research Articles

Acoustic radiation force imaging (ARFI) in the non-distended bladder does not predict abnormal urodynamic parameters in children.

Acoustic radiation force imaging (ARFI) is a recently developed form of ultrasound imaging that allows in vivo measurement of tissue stiffness. This technology could be useful at predicting bladder compliance in children. We hypothesize that tissue stiffness, as measured by ARFI, correlates with abnormal bladder compliance and capacity in patients with bladder dysfunction. Patients who presented for cystometrography (CMG) underwent ARFI of the bladder wall. Nine bladder wall shear wave speed (SWS) measurements were acquired using point and 2D ultrasound shear wave elastography. The mean for each ARFI technique was correlated to bladder compliance, calculated using Wahl's dimensionless number. ARFI parameters also were correlated with bladder capacity. A total of 25 patients were enrolled. Mean age at time of enrollment was 4.2±3.9 years (range two months to 15 years). There was no significant correlation between bladder compliance and point shear wave speed measurements (r=-0.22, p=0.31) or 2D shear wave speed measurements (r=-0.35, p=0.1). A total of 19 patients had bladder capacity below expected bladder capacity (EBC). There was no significant correlation between bladder capacity and point shear wave speed measurements (r =-0.08, p=0.7) or 2D shear wave speed measurements (r=-0.36, p=0.09). Our results did not demonstrate a significant correlation between bladder wall ARFI shear wave measurements and bladder compliance or bladder capacity. Further studies are warranted to determine whether ARFI may be used to predict abnormal urodynamic parameters in children.

Liver and Spleen Stiffness Surveillance Through Elastography During and After Direct-Acting Antiviral Therapy in Patients With Chronic Hepatitis C.

Direct-acting antiviral agents achieve a high cure rate, resulting in early hepatic necroinflammatory resolution and sustained fibrosis regression. This study aimed to obtain longitudinal, concurrent within-subject measurements of liver stiffness (LS) and spleen stiffness (SS) and their correlates over time. Participants with hepatitis C (n=592) receiving direct-acting antiviral-based therapy were monitored through point shear-wave elastography from the treatment baseline (TW0) across follow-up visits in terms of LS and SS. Generalized linear mixed modeling indicated that all LS values (2301 visits) were negatively correlated with the follow-up times (all P < .05) from TW0 to 24 weeks (PW24) after the end of treatment (EOT) and positively correlated with baseline LS values (P < .001). The slopes of declines (preceding minus next) differed significantly (P < .001) between TW0-TW4 (treatment week 4) (0.060 [-0.050 to 0.225] meter/second/month [m/s/mo]) and TW4-EOT (0.010 [-0.030 to 0.075] m/s/mo). All SS values (1704 visits) were negatively correlated with time only at PW24 (P < .001) and positively correlated with baseline SS values (P < .001). The slopes of the SS values differed significantly (P < .001) only between EOT-PW12 (-0.010 [-0.110 to 0.083] m/s/mo) and PW12-PW24 (0.043 [-0.063 to 0.160] m/s/mo). The biphasic fast-to-slow decline in LS occurred early in the on-treatment phase, which is consistent with the resolution of hepatic necroinflammation. The slow-to-fast decline in SS occurred off treatment. Future studies should investigate the association with regressions in liver fibrosis and portal hypertension.

Evaluation of ultrasound point shear wave elastography reliability in an elasticity phantom.

PurposeTo date, limited studies have specifically addressed the reliability of ultrasound point shear-wave elastography (pSWE). Therefore, the aim of the present study was to assess the reproducibility of ultrasound pSWE within and between operators using two ultrasound scanners.MethodsiU22 and EPIQ7 ultrasound scanners were used to assess the reliability of pSWE measurements of four inclusions [L I (8 kPa), L II (14 kPa), L III (48 kPa), and L IV (80 kPa)] at a depth of 3.5 cm in an elasticity phantom using a curvilinear 5-1 MHz transducer. The intra-operator, inter-operator, and inter-scanner reproducibility of pSWE was assessed using intraclass correlation coefficients (ICCs). Bland-Altman plots were used to establish bias and limits of agreement (LoA) between measurements. The accuracy of pSWE from manufacturer values was determined using the one-sample t-test.ResultsIntra-operator agreement was excellent, with an ICC >0.90. The bias in measurements for operator A was -0.36±3.13 kPa (LoA, -6.47 to 5.75), and for operator B it was 1.97±6.29 kPa (LoA, -10.25 to 14.21). Inter-operator agreement was excellent, with an ICC of 0.95. The bias in measurements between operators was -0.42±5.00 kPa (LoA, -10.24 to 9.38). The inter-scanner agreement between EPIQ7 and iU22 was excellent, with an ICC of 0.96. The bias in measurements between scanners was 1.74±4.44 kPa (LoA, -6.95 to 10.45). There was significant overestimation for L I (17.75%) and L II (31.14%) and underestimation for L III (-15.28%) and L VI (-98.00%) relative to the manufacturer-reported values.ConclusionPhantom ultrasound pSWE was reproducible within and between operators, and between Philips ultrasound scanners; further studies using different ultrasound systems and transducers are required.

Correlation Between Point Shear Wave Elastography and Liver Function Tests as A Predictor of Liver Fibrosis in Patients with Nonalcoholic Fatty Liver Disease

Background: Nowadays, generating shear waves and simulation of the liver tissue is done using point shear-wave elastographic (pSWE) techniques which uess acoustic radiation force impulse (ARFI). Objective: This study aimed to evaluate the correlation between pSWE and liver function tests (LFTs) to predict liver fibrosis in patients with non-alcoholic fatty liver disease (NAFLD). Materials and methods: It was a cross sectional study conducted in an Ultrasound Clinic in Suleymaniya city. The duration of the study was from 1st of November, 2018 to 30th of June, 2019 which conducted on 50 NAFLD patients. After confirming NAFLD diagnosis, the patients were referred to Ultrasound Clinic to go under pSWE test. Results: The data showed that the mean PSWE of NAFLD patient was 4.12±0.87 Kpa; and 18% of them had high PSWE (&gt; 4.6). Elastography fibrosis score was distributed to F0 (82%), F1 (6%), F2 (8%) and F3 (4%). There was a significant association between high APRI and high Aspartate Aminotransferase/Alanine Aminotransferase(AST/ALT) ratio (p=0.04). There was also a highly significant association between elastography fibrosis score and APRI fibrosis score among NAFLD patients (p&lt;0.001). Conclusion: This study showed that the pSWE is a valuable noninvasive diagnostic technique for predicting liver fibrosis among NAFLD patients and there is significant correlation between APRI and pSWE scores. Keywords: Non-alcoholic fatty liver disease, Point shears wave elastography, Liver fibrosis.

Correlation Between Point Shear Wave Elastography and Liver Function Tests as A Predictor of Liver Fibrosis in Patients with Nonalcoholic Fatty Liver Disease

Aim: of this study is to correlate between point shear wave elastography(pSWE) and liver function tests (LFTs) to predict liver fibrosis in patients with non-alcoholic fatty liver disease (NAFLD). Materials and methods: this study is a cross sectional study conducted in Ultrasound Clinic in Suleymaniya city. The duration of the study was through the period from 1st of November, 2018 to 30th of June, 2019 on 50 NAFLD patients. After confirming NAFLD diagnosis, the patients were referred to Ultrasound Clinic to complete Point Shear Wave Elastography (PSWE). Results: showed a mean PSWE of NAFLD patient was 4.12±0.87 Kpa; 18% of them had high PSWE (&gt; 4.6). Elastography fibrosis score was distributed to F0 (82%), F1 (6%), F2 (8%) and F3 (4%). The Aspartate Aminotransferase Platelet Ratio Index (APRI) fibrosis scores were distributed to F0 (48%), F1-3 (48%) and F4 (4%), There was a highly significant association between elastography fibrosis score and APRI fibrosis score of NAFLD patients (p&lt;0.001), There was no significant association between elastography fibrosis score and Aspartate Aminotransferase/Alanine Aminotransferase (AST/ALT) values of NAFLD patients (p=0.5). Conclusion: this study showed that the point shear wave elastography is a valuable noninvasive diagnostic technique for predicting significant liver fibrosis among patients with non-alcoholic liver fatty diseases and there is significant correlation between APRI score and pSWE score. The current gold standard in the diagnosis and staging of liver fibrosis is liver biopsy. Point shear wave elastography is among the noninvasive procedures to assess liver fibrosis. Keywords: Non-alcoholic fatty liver disease, Point shears wave elastography, Liver fibrosis.

Point Shear Wave Elastography (pSWE) for Evaluating Relation between Laboratory Renal Function Deterioration in Chronic Kidney Disease (CKD) and Degree of Renal StiffnessPoint Shear Wave Elastography (pSWE) for Evaluating Relation between Laboratory Renal Function Deterioration in Chronic Kidney Disease (CKD) and Degree of Renal Stiffness

Abstract Aim of Work: To evaluate the role of point shear wave elastography (pSWE) in detecting degree of renal fibrosis and correlating it to deterioration of renal function in chronic kidney disease patients. Background: Chronic kidney disease (CKD) is diagnosed by either of the following lasting for more than 3 months: Decrease of glomerular filtration rate (GFR) less than 60ml/min/1.73m2 which is the best index of kidney function, or presence of markers for kidney damage as albuminuria. Renal fibrosis is nearly the ultimate common pathway for all CKD. The main method in clinical use for the assessment of renal fibrosis is the renal biopsy which is known for its considerable disadvantages like its invasive nature, with a risk of further complications, high cost, inter-observer varia-bility, and sampling error. Shear wave elastography (SWE) is one of the promising techniques that allow non-invasive estimation of tissue stiffness. Material and Methods: This study was performed at the Radiodiagnosis Department, Zagazig University. We examined 42CKD patients who underwent pSWEas well as laboratory detection of Estimated glomerular filtration rate (eGFR). Patients were classified according to GFR into fivestages: Into stage 1 (eGFR ³90), stage 2 (eGFR 60-89), stage 3 (eGFR 30-59), stage 4 (eGFR 15-29), and stage 5 (eGFR <15). All analyses were done using the Statistical Package for theSocial Sciences 20.0 software. Results: The mean value of SWE (kPa) in CBD patients (5.44±1.4). The mean SWE values in the CKD stages were 3.65±0.9, 4.5±1.2, 5.8±0.5, 5.3±1.1, 6.6±0.9 kPa in stages 1,2,3,4, and 5 respectively. There was no significant difference between CKD stages except between stage 1 vs. 5 and stage 2 vs. 5.Only age showed a significant correlation with SWE in CKD patients (r=0.453; p=0.039). The laboratory investi-gationrevealed that 6 patients stage I (110±26.5), 8 patients stage II (71.5±1), 8 patients stage III (45.5±8.3), 6 patients stage IV (23±6.2) and 14 patients stage V (8.3±2.8). The cut-off value for predicting CKD was 4.05 kPa with 85.70% sensitivity and 90.5% specificity, while for predicting kidney fibrosis it was 4.45 kPa with 93.3% sensitivity and 83.3% specificity. Conclusion: Our results suggest that SWE can distinguish between normal subjects and patients with CKD. It also can detect renal fibrosis but cannot correlate with different CKD stages detected by GFR.

Comparison of Sound Touch Elastography, Sound Touch Quantify, and 4 Serum Fibrosis Indexes for the Diagnosis of Liver Fibrosis in Patients With Chronic Hepatitis B.

The aim of this research was to compare the use of shear wave elastography (sound touch elastography [STE] and sound touch quantify [STQ]) and serum liver fibrosis indexes in the evaluation and staging of chronic hepatitis B (CHB) liver fibrosis. Sound touch elastography is a form of 2-dimensional shear wave elastography, and STQ is a form of point shear wave elastography. Between June 2018 and March 2019, 122 patients with CHB were assessed using STE and STQ. Serum liver biomarkers tests were undertaken, and liver biopsy was performed, and these were used to assign a pathological stage based on the Scheuer scoring system. A receiver operating characteristic curve was used to analyze the diagnostic value of noninvasive methods for evaluating and staging liver fibrosis. The cutoff values of STE for liver fibrosis stages S2 to S4 were 8.85, 9.97, and 10.29 kPa, respectively, and the areas under the receiver operating characteristic (AUCs) curve were 0.703, 0.821, and 0.900, respectively. The cutoff values of STQ for liver fibrosis stages S2 to S4 were 11.31, 13.81, and 20.60 kPa, respectively, and the AUCs were 0.674, 0.807, and 0.893, respectively. The AUCs of STE and STQ in diagnosing fibrosis stage were significantly higher than those of liver serum biomarkers (P < 0.05). The AUCs for the ability of the aspartate transaminase-to-platelet ratio index, the fibrosis index based on the 4 factors, the King score, and the Forns index to diagnose S2 fibrosis were 0.502, 0.624, 0.542, and 0.616, respectively, and the AUCs for their ability to diagnose S4 fibrosis were 0.856, 0.861, 0.883, and 0.823, respectively. Both STE and STQ are noninvasive methods for the assessment of liver fibrosis in CHB patients, with better diagnostic performances than those of 4 serum fibrosis indexes.

Comparison of point and two-dimensional shear wave elastography of the spleen in healthy subjects.

BACKGROUNDFew systematic comparative studies of the different methods of physical elastography of the spleen are currently available.AIMTo compare point shear wave and two-dimensional elastography of the spleen considering the anatomical location (upper, hilar, and lower pole).METHODSAs part of a prospective clinical study, healthy volunteers were examined for splenic elasticity using four different ultrasound devices between May 2015 and April 2017. The devices used for point shear wave elastography were from Siemens (S 3000) and Philips (Epiq 7), and those used for two-dimensional shear wave elastography were from GE (Logiq E9) and Toshiba (Aplio 500). In addition, two different software versions (5.0 and 6.0) were evaluated for the Toshiba ultrasound device (Aplio 500). The study consisted of three arms: A, B, and C.RESULTSIn study arm A, 200 subjects were evaluated (78 males and 122 females, mean age 27.9 ± 8.1 years). In study arm B, 113 subjects were evaluated (38 men and 75 women, mean age 26.0 ± 6.3 years). In study arm C, 44 subjects were enrolled. A significant correlation of the shear wave velocities at the upper third of the spleen (r = 0.33088, P < 0.0001) was demonstrated only for the Philips Epiq 7 device compared to the Siemens Acuson S 3000. In comparisons of the other ultrasound devices (GE, Siemens, Toshiba), no comparable results could be obtained for any anatomical position of the spleen. The influencing factors age, gender, and body mass index did not show a clear correlation with the measured shear wave velocities.CONCLUSIONThe absolute values of the shear wave elastography measurements of the spleen and the two different elastography methods are not comparable between different manufacturers or models.

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

BackgroundAcoustic 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.ObjectiveOur 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 methodsSpleen 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.ResultsThere 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.ConclusionNormal 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.

Diagnostic accuracy of elastography and magnetic resonance imaging in patients with NAFLD: A systematic review and meta-analysis

Vibration-controlled transient elastography (VCTE), point shear wave elastography (pSWE), 2-dimensional shear wave elastography (2DSWE), magnetic resonance elastography (MRE), and magnetic resonance imaging (MRI) have been proposed as non-invasive tests for patients with non-alcoholic fatty liver disease (NAFLD). This study evaluated their diagnostic accuracy for liver fibrosis and non-alcoholic steatohepatitis (NASH). PubMED/MEDLINE, EMBASE and the Cochrane Library were searched for studies examining the diagnostic accuracy of these index tests, against histology as the reference standard, in adult patients with NAFLD. Two authors independently screened and assessed methodological quality of studies and extracted data. Summary estimates of sensitivity, specificity and area under the curve (sAUC) were calculated for fibrosis stages and NASH, using a random effects bivariate logit-normal model. We included 82 studies (14,609 patients). Meta-analysis for diagnosing fibrosis stages was possible in 53 VCTE, 11 MRE, 12 pSWE and 4 2DSWE studies, and for diagnosing NASH in 4 MRE studies. sAUC for diagnosis of significant fibrosis were: 0.83 for VCTE, 0.91 for MRE, 0.86 for pSWE and 0.75 for 2DSWE. sAUC for diagnosis of advanced fibrosis were: 0.85 for VCTE, 0.92 for MRE, 0.89 for pSWE and 0.72 for 2DSWE. sAUC for diagnosis of cirrhosis were: 0.89 for VCTE, 0.90 for MRE, 0.90 for pSWE and 0.88 for 2DSWE. MRE had sAUC of 0.83 for diagnosis of NASH. Three (4%) studies reported intention-to-diagnose analyses and 15 (18%) studies reported diagnostic accuracy against pre-specified cut-offs. When elastography index tests are acquired successfully, they have acceptable diagnostic accuracy for advanced fibrosis and cirrhosis. The potential clinical impact of these index tests cannot be assessed fully as intention-to-diagnose analyses and validation of pre-specified thresholds are lacking. Non-invasive tests that measure liver stiffness or use magnetic resonance imaging (MRI) have been suggested as alternatives to liver biopsy for assessing the severity of liver scarring (fibrosis) and fatty inflammation (steatohepatitis) in patients with non-alcoholic fatty liver disease (NAFLD). In this study, we summarise the results of previously published studies on how accurately these non-invasive tests can diagnose liver fibrosis and inflammation, using liver biopsy as the reference. We found that some techniques that measure liver stiffness had a good performance for the diagnosis of severe liver scarring.

Elastography for characterization of focal liver lesions: current evidence and future perspectives.

Focal liver lesions (FLLs) are a common finding during routine abdominal ultrasound (US). The differential diagnosis between diverse types of FLLs, especially between benign and malignant ones, is extremely important and can often be particularly challenging. Radiological techniques with contrast administration and/or liver biopsy are mostly necessary for establishing diagnosis, but they have several contraindications or complications. Due to limitations of these tools, there is urgent and still unmet need to develop a first line, non-invasive and simple method to diagnose FLLs. Elastography is an US-based imaging modality that provides information about the physical parameter corresponding to the tissue stiffness and can be considered a virtual biopsy. Several elastographic approaches have been developed, such as transient elastography, strain imaging and share wave imaging, which include point shear wave elastography and 2D shear wave elastography. These tools are already in use for evaluating liver fibrosis and in the assessment of focal lesions in other organs, like breast and thyroid gland. This review aims to assess the current evidence of different techniques based on elastography in the setting of FLLs, in order to evaluate accuracy, limitations and future perspectives. In particular, we focused on two contexts: the ability of discriminating between benign and malignant lesions, especially hepatocellular carcinoma and liver metastasis, and the surveillance after percutaneous therapy. This could have a high clinical impact making elastography crucial to identify the appropriate management of FLLs.

Measurements of Serum Mac-2-Binding Protein Glycosylation Isomer and Shear Wave Velocity in Health Checkups Are Useful in Screening for Non-Alcoholic Steatohepatitis.

Liver-related mortality rates in patients with non-alcoholic steatohepatitis (NASH) increase with advancing liver fibrosis stage. The present study aimed to elucidate whether adding non-invasive liver fibrosis tests to a comprehensive health checkup system is useful for NASH screening. Both serum Mac-2-binding protein glycosylation isomer (M2BPGi) and point shear wave elastography (pSWE) using ultrasonography were performed for 483 health checkup subjects who consented to participate in this prospective study. Outcomes in positive subjects were surveyed 1 year later. Eighty-eight subjects (18%) showed positive results for at least one liver fibrosis test, with 63 subjects positive for pSWE, 33 subjects positive for M2BPGi, and 72 subjects showing no significant elevation of liver enzymes. The secondary consultation rate for positive subjects was 52% (46/88). However, as 15 of those 46 subjects visited a non-liver-specialist and could not undergo detailed examination, the secondary examination rate was only 35% (31/88). For the 31 subjects who received secondary examination, NASH was diagnosed in 14 subjects, other chronic liver disease (CLD) in 6 subjects, and no CLD in 11 subjects. Additional liver fibrosis tests using M2BPGi and pSWE appear useful in health checkups when screening for CLD, especially for NASH.

Is There a Place for Elastography in the Diagnosis of Hepatocellular Carcinoma?

Background and Aims: Elastography can provide information regarding tissue stiffness (TS). This study aimed to analyze the elastographic features of hepatocellular carcinoma (HCC) and the factors that influence intratumoral elastographic variability in patients with liver cirrhosis. Methods: This prospective study included 115 patients with liver cirrhosis and hepatocellular carcinoma evaluated between June 2016–November 2019. A total of 88 HCC nodules visualized in conventional abdominal ultrasound (US) met the inclusion criteria and underwent elastographic evaluation. Elastographic measurements (EM) were performed in HCC and liver parenchyma using VTQ (Virtual Touch Quantification), a point shear wave elastography (pSWE) technique. In all patients, we performed contrast-enhanced ultrasound (CEUS), and the final diagnosis of HCC was established by contrast-enhanced-CT or contrast-enhanced-MRI. Results: The mean VTQ values in HCCs were 2.16 ± 0.75 m/s. TS was significantly lower in HCCs than in the surrounding liver parenchyma 2.16 ± 0.75 m/s vs. 2.78 ± 0.92 (p < 0.001). We did not find significant differences between the first five and the last five EM, and the intra-observer reproducibility was excellent ICC: 0.902 (95% CI: 0.87–0.950). However, the tumor size, heterogeneity, and depth correlated with higher intralesional stiffness variability (p < 0.001). Conclusions: VTQ brings additional information for HCC characterization. Intra-observer reproducibility for both HCC and liver parenchyma was excellent. Knowing the stiffness of HCC’s might endorse an algorithm-based approach towards focal liver lesions (FLLs) in liver cirrhosis.

Point shear wave elastography of the liver in healthy adult cats.

To evaluate stiffness of the liver parenchyma in healthy adult cats by means of point shear wave elastography (PSWE). 18 client-owned adult (1- to 6-year-old) healthy cats. Echogenicity and echotexture of the liver parenchyma were assessed by means of conventional B-mode ultrasonography. The shear wave velocity (Vs) of the right and left portions of the liver were measured by means of PSWE. B-mode ultrasonography revealed no abnormalities in echotexture or echogenicity of the liver parenchyma in any cat. Mean (95% CI) Vs in the liver parenchyma was 1.46 m/s (1.36 to 1.55 m/s) for the right portion, 1.36 m/s (1.26 to 1.47 m/s) for the left portion, and 1.43 m/s (1.35 to 1.51 m/s) overall. The difference in mean Vs between the 2 portions of the liver was significant. No significant correlation was found between Vs and body weight or between Vs and the depth at which this variable was measured. Quantitative PSWE of the liver was feasible in healthy adult cats. The obtained values for Vs may be useful for interpretation of and comparison with values measured in cats with liver disease. Additional research is needed to explore the potential usefulness of PSWE for diagnostic purposes.

Diagnostic Performance of ElastPQ Point Shear Wave Elastography for Hepatic Fibrosis in Hepatitis B and Hepatitis C Patients

Diagnostic Performance of ElastPQ Point Shear Wave Elastography for Hepatic Fibrosis in Hepatitis B and Hepatitis C Patients

Ultrasound shear wave elastography: does it add value to gray-scale ultrasound imaging in differentiating biliary atresia from other causes of neonatal jaundice?

Neonatal/infantile jaundice is relatively common, and most cases resolve spontaneously. However, in the setting of unresolved neonatal cholestasis, a prompt and accurate assessment for biliary atresia is vital to prevent poor outcomes. To determine whether shear wave elastography (SWE) alone or combined with gray-scale imaging improves the diagnostic performance of US in discriminating biliary atresia from other causes of neonatal jaundice over that of gray-scale imaging alone. Infants referred for cholestatic jaundice were assessed with SWE and gray-scale US. On gray-scale US, two radiology readers assessed liver heterogeneity, presence of the triangular cord sign, hepatic artery size, presence/absence of common bile duct and gallbladder, and gallbladder shape; associated interobserver correlation coefficients (ICC) were calculated. SWE speeds were performed on a Siemens S3000 using 6C2 and 9L4 transducers with both point and two-dimensional (2-D) SWE US. Both univariable and multivariable analyses were performed, as were receiver operating characteristic curves (ROC) and statistical significance tests (chi-squared, analysis of variance, t-test and Wilcoxon rank sum) when appropriate. There were 212 infants with biliary atresia and 106 without biliary atresia. The median shear wave speed (SWS) for biliary atresia cases was significantly higher (P<0.001) than for non-biliary-atresia cases for all acquisition modes. For reference, the median L9 point SWS was 2.1m/s (interquartile range [IQR] 1.7-2.4m/s) in infants with biliary atresia and 1.5m/s (IQR 1.3-1.9m/s) in infants without biliary atresia (P<0.001). All gray-scale US findings were significantly different between biliary-atresia and non-biliary-atresia cohorts (P<0.001), intraclass correlation coefficient (ICC) range 0.7-1.0. Triangular cord sign was most predictive of biliary atresia independent of other gray-scale findings or SWS - 96% specific and 88% sensitive. Multistep univariable/multivariable analysis of both gray-scale findings and SWE resulted in three groups being predictive of biliary atresia likelihood. Abnormal common bile duct/gallbladder and enlarged hepatic artery were highly predictive of biliary atresia independent of SWS (100% for girls and 95-100% for boys). Presence of both the common bile duct and the gallbladder along with a normal hepatic artery usually excluded biliary atresia independent of SWS. Other gray-scale combinations were equivocal, and including SWE improved discrimination between biliary-atresia and non-biliary-atresia cases. Shear wave elastography independent of gray-scale US significantly differentiated biliary-atresia from non-biliary-atresia cases. However, gray-scale findings were more predictive of biliary atresia than elastography. SWE was useful for differentiating biliary-atresia from non-biliary-atresia cases in the setting of equivocal gray-scale findings.

Spleen Stiffness for Predicting Varices Needing Treatment: Comparison between Two Different Elastography Techniques (Point vs. 2D-SWE).

The study aimed to establish the benefits of using spleen stiffness values measured by two elastography techniques as noninvasive markers for predicting varices needing treatment and comparing their performances. A prospective study was performed, including 107 subjects with compensated liver cirrhosis, who underwent upper digestive endoscopy, as well as spleen stiffness measurements by means of two elastography techniques: pSWE (point shear wave elastography using Virtual Touch Quantification-Siemens Acuson S2000) and 2D-SWE (2D-shear wave elastography-LOGIQ E9, General Electric). Reliable spleen stiffness measurements were obtained in 96.2% (103/107) patients by means of 2D-SWE and in 94.4% (101/107) subjects with pSWE; therefore, 98 subjects were included in the final analysis, of which 40.8% (40/98) had varices needing treatment. The optimal spleen stiffness cut-off value by 2D-SWE for predicting varices needing treatment was 13.2 kPa (AUROC 0.84), while for pSWE, it was 2.91 m/s (AUROC 0.90). Based on AUROC comparison, no difference between the performance of the two techniques for predicting varices needing treatment was found (p=0.1606). In conclusion, spleen stiffness measured by either 2D-SWE or pSWE is a reliable surrogate marker, with good feasibility, applicability, and predictive accuracy for varices needing treatment, with no significant difference between techniques.

Clinical use of shear-wave elastography for detecting liver fibrosis in children and adolescents with cystic fibrosis.

Complications from liver cirrhosis are a leading cause of death in children with cystic fibrosis. Identifying children at risk for developing liver cirrhosis and halting its progression are critical to reducing liver-associated mortality. Quantitative US imaging, such as shear-wave elastography (SWE), might improve the detection of liver fibrosis in children with cystic fibrosis (CF) over gray-scale US alone. We incorporated SWE in our pediatric CF liver disease screening program and evaluated its performance using magnetic resonance (MR) elastography. Ninety-four children and adolescents with CF underwent 178 SWE exams, aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyl transferase (GGT) and platelet measurements. Of these, 27 children underwent 34 MR elastography exams. We evaluated SWE performance using 6-MHz and 9-MHZ point SWE, and 9-MHz two-dimensional (2-D) SWE. The 6-MHz point SWE was the only method that correlated with MR elastography (r=0.52; 95% confidence interval [CI] 0.20-0.74; P=0.003). SWE of 1.45m/s distinguished normal from abnormal MR elastography (79% sensitivity, 100% specificity, 100% positive predictive value [PPV], 55% negative predictive value [NPV], area under the receiver operating characteristic [AUROC] curve 0.94). SWE of 1.84m/s separated mild-moderate (3.00-4.77kPa) from severe (>4.77kPa) MR elastography (88% sensitivity, 86% specificity, 78% PPV, 93% NPV, AUROC 0.79). Elevations of AST, ALT, GGT and thrombocytopenia were associated with higher SWE. AST-to-platelet ratio index of 0.42, fibrosis-4 of 0.29, and GGT-to-platelet ratio of 1.43 all had >95% NPV for SWE >1.84m/s. Given its correlation with MR elastography, SWE might be a clinically useful predictor of liver fibrosis. We identified imaging criteria delineating the use of SWE to identify increased liver stiffness in children with CF. With multicenter validation, these data might be used to improve the detection and monitoring of liver fibrosis in children with CF.

Cystic fibrosis and noninvasive liver fibrosis assessment methods in children.

Noninvasive assessments of liver fibrosis are currently used to evaluate cystic fibrosis (CF)-related liver disease. However, there is scarce data regarding their repeatability and reproducibility, especially in children with CF. The present study aimed to evaluate the repeatability and reproducibility of transient elastography (TE) (FibroScan®) and point shear-wave elastography using virtual touch quantification (pSWE VTQ) in children with CF. TE and pSWE VTQ were performed in 56 children with CF by two different operators. Analysis of repeatability and reproducibility was available in 33 patients for TE and 46 patients for pSWE VTQ. Intra- and interobserver agreement were assessed using the intraclass correlation coefficient (ICC) and their 95% confidence interval (CI), and Bland and Altman graphs. For TE, ICC was 0.91 (0.83-0.95) for intraobserver agreement and 0.92 (95% CI: 0.86-0.96) for interobserver agreement. For pSWE VTQ, ICC was 0.83 (0.72-0.90) for intraobserver agreement and 0.67 (0.48-0.80) for interobserver agreement. Both technics can be proposed in the follow-up of patients, according to their availability in CF centers. This study shows that TE and pSWE VTQ are reliable methods to evaluate liver fibrosis in children with CF. This study shows for the first time that TE and pSWE VTQ are both repeatable and reproducible in children with CF. These data indicate that both TE and pSWE VTQ can be proposed for the follow-up of patients with CF, according to their availability in each CF center.

Determining the effects of excess weight on renal cortical stiffness in children and adolescents with point Shear Wave Elastography.

To determine the early effects of excess weight on renal cortical stiffness in children and adolescents using point shear wave elastography (pSWE). One hundred and forty-six overweight and obese children (43.2% male; mean age, 12.6±2.9 years: range 4.3-18) and 48 lean children (27.1% male: mean age, 12.4±3.4: range 4.8-18.9) were included in the study and control group, respectively. pSWE measurements of the two kidneys were performed. The mean value of shear wave velocity was compared between groups. The mean shear wave velocity was 2.79±0.53 m/s for the control subjects and 3.09±0.59 m/s for the overweight-obese subjects. The differences between the two groups were sta-tistically significant (p=0.001). There was no correlation between shear wave velocity and age or depth. A positive correlation was found between shear wave velocity and body mass index, body mass index-standard deviation score. Renal cortical stiffness was higher in children with excess weight than in lean children. This study is the first attempt at applying pSWE to investigate the early adverse effects of excess weight.