Liver Shear Wave Velocity Research Articles

Effectiveness of 1-year pemafibrate treatment on steatotic liver disease: the influence of alcohol consumption.

Pemafibrate is a selective peroxisome proliferator-activated receptor α modulator that improves serum alanine aminotransferase (ALT) in dyslipidemia patients. We previously reported that pemafibrate significantly improves liver function, serum triglyceride (TG) levels and liver stiffness in non-alcoholic fatty liver disease patients, however the influence of alcohol consumption was not considered. Therefore, we explored pemafibrate efficacy in patients with steatotic liver disease (SLD) and alcohol-associated liver disease (ALD). We retrospectively evaluated pemafibrate efficacy on liver enzymes and lipids in metabolic dysfunction-associated SLD (MASLD) (n = 93), MASLD plus increased alcohol intake (MetALD; n = 23) and ALD (n = 22) patients who had taken pemafibrate for at least 48 weeks. Liver shear wave velocity (SWV, n = 75) was also evaluated. In MASLD group, ALT, aspartate aminotransferase (AST), γ-glutamyl transpeptidase (γ-GTP) and TG values were significantly decreased from baseline to week 24 and week 48 (P < 0.0001). ALT and TG values in MetALD group and ALT and AST values in ALD group were also significantly decreased from baseline to week 24 and week 48. Study participant SWV values decreased from baseline to week 48. We observed no significant difference in changes to ALT, AST, γ-GTP and TG (value at week 24 or week 48 minus value at baseline) among the three groups. Pemafibrate improves liver function and liver stiffness thus making it a promising therapeutic agent for SLD, even in patients with excess alcohol consumption (MetALD and ALD groups).

Evaluation of hepatic functional reserve of hepatocellular carcinoma (≤ 5 cm) by liver shear wave velocity combined with multiple parameters.

Normal hepatic functional reserve is the key to avoiding liver failure after liver surgery. This study investigated the assessment of hepatic functional reserve using liver shear wave velocity (LSWV) combined with biochemical indicators, tumor volume, and portal vein diameter. In this single-center prospective study, a total of 123 patients with hepatocellular carcinoma (HCC) were divided into a test group (n=92) and a validation group (n=31). All patients were Child-Pugh grade A. The indocyanine green retention rate at 15 min (ICG-R15), liver shear wave velocity (LSWV), portal vein diameter (Dpv), alanine aminotransferase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), γ-glutamyl transpeptidase (γ-GGT), albumin (ALB), prothrombin time (PT), and also liver tumor volume (maximum diameter ≤5 cm) were measured. In the test group, multiple parameters were used to evaluate hepatic functional reserve, and the multiparametric model was established. Receiver operating characteristic (ROC) curve analysis was conducted to assess the diagnostic performance of the multiparametric model. In the validation group, the predictive effectiveness of the multiparametric model was analyzed using consistency tests. It was revealed that LSWV, ALB, and PT were statistically significant in evaluation of the hepatic functional reserve (P<0.05). The multiparametric model was formulated as follows: Y= -18.954 + 9.726*LSWV-0.397*ALB+2.063*PT. The value of the area under the curve (AUC) for the multiparametric model was 0.913 (95% confidence interval (CI): 0.835-0.962, P< 0.01), with a cutoff value of 16.656 (sensitivity, 0.763; specificity, 0.926). The Kappa value of consistency testing was 0.655 (P<0.01). LSWV combined with ALB and PT exhibited a high predictive effectiveness for the assessment of hepatic functional reserve, assisting the clinical diagnosis and management of liver diseases.

Effect of pemafibrate on liver enzymes and shear wave velocity in non-alcoholic fatty liver disease patients.

Pemafibrate is a selective peroxisome proliferator-activated receptor α modulator that improves serum alanine aminotransferase (ALT) in dyslipidemia patients. Pemafibrate was reported to reduce ALT in non-alcoholic fatty liver disease (NAFLD) patients, but efficacy was not clearly elucidated due to the small size of previous study populations. Therefore, we explored pemafibrate efficacy in NAFLD patients. We retrospectively evaluated pemafibrate efficacy on liver enzymes (n = 132) and liver shear wave velocity (SWV, n = 51) in NAFLD patients who had taken pemafibrate for at least 24 weeks. Patient ALT levels were decreased from 81.0 IU/L at baseline to 48.0 IU/L at week 24 (P < 0.0001). Serum levels of aspartate aminotransferase (AST), γ-glutamyl transpeptidase (γ-GTP) and triglyceride (TG) were significantly decreased, and high-density lipoprotein cholesterol and platelet count were significantly increased, with no change in body weight being observed. Study participant SWV values decreased from 1.45 m/s at baseline to 1.32 m/s at week 48 (P < 0.001). Older age (P = 0.035) and serum TG levels (P = 0.048) were significantly associated with normalized ALT. Changes in AST, ALT, γ-GTP and body weight were significantly correlated with change in SWV. Pemafibrate significantly improves liver function, serum TG and liver stiffness in NAFLD patients. Pemafibrate is a promising therapeutic agent for NAFLD and may be a candidate for NAFLD patients with elevated TG.

The effect of water intake on ultrasound tissue characteristics and hemodynamics of adult livers.

Aim of the studyTo assess the effect of water intake on ultrasound tissue characteristics and hemodynamics of adult livers.Material and methodsIn February 2020, we prospectively performed ultrasound shear wave elastography and attenuation imaging (ATI) of the liver parenchyma, and spectral Doppler sonography of the portal vein and hepatic artery in 19 adult healthy volunteers (10 men and 9 women, mean age 27 years, mean body mass index 24.65 kg/m2). We measured liver shear wave velocity (SWV, m/s), shear wave dispersion (SWD, m/s/kHz), attenuation coefficient (dB/cm/MHz), main portal vein velocity (PVV, cm/s), hepatic artery peak systolic velocity (PSV, cm/s), and end diastolic velocity (EDV, cm/s) immediately before and at different time points (15, 30, 45, and 60 minutes) after water intake (1.0 l water and 1.5 l water for body weight < 150 lbs. and ≥ 150 lbs., respectively).ResultsThe differences in SWV, PVV, hepatic artery PSV and EDV before and after water intake were significant (p < 0.01) whereas the differences in SWD and ATI were not (p > 0.05) based on repeated measures ANOVA tests. The values of SWV, PVV, PSV, and EDV reached a peak at 30-45 minutes and returned to baseline 60 minutes after water intake. We observed positive correlations of SWV with PVV, PSV, and EDV in linear regression analyses (r2 > 0.73).ConclusionsWater intake affects the liver stiffness and hemodynamics. No water intake at least one hour prior to liver ultrasound elastography and Doppler sonography is recommended.

Comparison of the diagnostic value of virtual touch tissue quantification and virtual touch tissue imaging quantification in infants with biliary atresia.

This study aimed to compare the diagnostic performance of vital touch tissue quantification (VTQ) and virtual touch tissue imaging quantification (VTIQ) in diagnosing infants with biliary atresia (BA) from jaundiced infants. In this study, 26 jaundiced infants with BA, 33 jaundiced infants without BA, and 40 normal infants were enrolled. The hepatic shear wave velocity (SWV) of each infant was determined by VTQ and VTIQ examinations, respectively. Then, the receiver operating characteristic (ROC) curves were drawn and the area under the curve (AUC) and optimal cut-off values were calculated to evaluate the sensitivities and specificities of VTIQ and VTQ for BA. The mean values of SWV of the control group measured by VTQ and VTIQ were (1.09±0.18) m/s and (1.36±0.21) m/s, respectively. The mean values of SWV of the non-BA group measured by VTQ and VTIQ were (1.30±0.28) m/s and (1.52±0.29) m/s, respectively. The mean values of SWV of the BA group measured by VTQ and VTIQ were (2.36±0.36) m/s and (2.43±0.29) m/s, respectively. The diagnostic threshold of VTQ and VTIQ to diagnose BA was 1.77 and 1.92m/s. The sensitivities of VTQ and VTIQ to diagnose BA were 90.9% and 95.5%. The specificities of VTQ and VTIQ to diagnose BA were 68.4% and 78.9%. Vital touch tissue quantification and VTIQ could help distinguish infants with BA from jaundiced infants by measuring the liver SWV values. VTIQ has higher sensitivity and specificity than VTQ.

Can Point Shear Wave Elastography Be Used as an Early Indicator of Involvement?: Evaluation of the Pancreas and Liver in Children With Cystic Fibrosis.

The aim of this study was to determine the effect of cystic fibrosis (CF) on pancreas and liver elasticity in young children using point shear wave elastography and to determine the relationship with clinical findings. Twenty-two patients with genetically proven CF, who were admitted to our pediatric gastroenterology clinic, and 22 healthy control participants were enrolled in the study. The shear wave velocity (SWV) of the liver and pancreas were measured with point shear wave elastography. The 22 patients with CF included 45.5% girls with a mean age ± SD of 35 ± 35.8 months (range, 5-123 months). The 22 healthy control participants included 41.2% girls with a mean age of 58.9 ± 44.4 months (range, 2-159 months). The mean SWV of the pancreas in the patients with CF (1.06 ± 0.26 m/s) was significantly higher than that of the healthy control participants (0.85 ± 0.23 m/s; P = .01). The mean SWV of the liver in the patients with CF (1.46 ± 0.24 m/s) was significantly higher than that of the healthy control participants (1.12 ± 0.21 m/s; P = .001). The SWV of the pancreas and liver did not show any significant differences depending on ursodeoxycholic acid use, malnutrition status, and the presence of the F508 deletion mutation. This study showed an increased SWV of the pancreas in children with CF, contrary to the literature. We also found an increased liver SWV even in the absence of CF-related liver disease. Ultrasound elastography may be a useful method of evaluating early changes in the pancreas and liver before the obvious clinical, laboratory, and B-mode ultrasound signs of CF-related involvement.

Role of Virtual Touch Tissue Imaging Quantification in the Assessment of Hepatic Sinusoidal Obstruction Syndrome in a Rat Model.

To investigate the value of liver stiffness in rats with various degrees of hepatic sinusoidal obstruction syndrome (HSOS) induced by monocrotaline by comparing liver histopathologic findings. Seventy rats were randomly divided into a control group (n = 10), a low-dose monocrotaline group (n = 30), and a high-dose monocrotaline group (n = 30). After successful modeling, the liver shear wave velocity (SWV) by Virtual Touch tissue imaging quantification (Siemens Medical Solutions, Mountain View, CA) and the alanine aminotransferase (ALT), aspartate aminotransferase (AST), and total bilirubin levels of the groups were obtained on days 3 and 5, and the intergroup differences were compared. Liver histopathologic characteristics were analyzed to evaluate the degrees of HSOS, and the scores were recorded. On days 3 and 5, the total bilirubin, AST, and ALT, levels and liver SWV in the low- and high-dose groups were elevated; the portal vein velocity (PVV) of these groups was decreased compared with the control group; and the high-dose rats showed higher serum AST and ALT levels than the low-dose rats. The high-dose rats had a lower PVV than the low-dose rats at day 3. The liver SWV values had significant correlations with the histologic score and PVV. In a multivariate analysis, the liver SWV (β = 0.813; P < .001) was independently associated with the histopathologic score. Liver stiffness as measured by Virtual Touch tissue imaging quantification increases with the severity of HSOS and can be recommended as a marker for diagnosis and assessment of HSOS.

Acoustic radiation force impulse (ARFI) elastography to asses maternal and foetal structures in pregnant ewes.

The aim of this study was to evaluate the stiffness of foetal lungs, liver, kidneys and placentomes by acoustic radiation force impulse (ARFI) elastography in ovine and to correlate obtained findings with foetal development. Twenty-four ewes were included, and tissue stiffness of foetal lung, liver, kidney and placentome was measured beginning with 10th gestational week by qualitative-quantitative ARFI elastography. A total of 33 healthy lambs were born. Qualitative elastographic analysis permitted to classify maternal and foetal tissues elasticity in decreasing order as follows: placentome, kidney, liver and lung. Regarding quantitative ARFI elastography data, shear wave velocity (SWV) of foetal lung and liver varied. The lung SWV decreased gradually from the 16th to the 21st gestational week (R2 =0.80; p<0.001), while liver SWV increased gradually from the 14th to 21st gestational week (R2 =0.80; p<0.001). In contrast, the kidneys and placentomes SWV's remained constant through gestation (p=0.076; and 0.34). ARFI elastography was shown feasible for evaluation of maternal and foetal tissues stiffness in the ovine model. It can be used to demonstrate pulmonary and hepatic stiffness modifications during foetal development.

Elastographic and echotextural characteristics of foetal lungs and liver during the final 5 days of intrauterine development in dogs

Objective was to evaluate the echotexture and characteristics during terminal development of canine foetal respiratory and hepatic systems through elastographic examinations. Fifteen pregnant bitches were evaluated by ultrasonography twice daily, from the 53rd gestational day until whelping, and images obtained from 120 to 0 h before parturition were analysed. Images of foetal lungs and liver were recorded and then used for computer-assisted analyses to determine quantitative attributes. Acoustic Radiation Force Impulse (ARFI) elastographic of internal organs were classified as ‘soft’ (white areas) or ‘hard’ (dark areas) and quantitative analyses determined the mean shear wave velocities (SWV) of foetal lungs and liver. After delivery, canine neonates were clinically evaluated, and their health status was monitored weekly until 60 days post-partum. Sonographic parameters over time were compared by ANOVA and Pearson’s correlations were used to determine associations between SWVs and echotextural variables. Foetal lungs and liver had a homogeneous echotexture and pulmonary parenchyma appeared hyperechoic when compared with that of the liver. Mean numerical pixel values (NPVs) of lungs decreased from 120 to 24 h and subsequently increased until parturition (P = 0.04). Lungs and liver mean (± SD) SWVs (0.98 ± 0.12 and 0.84 ± 0.11 m/s, respectively) didn’t vary (P > 0.05) over time. Fluctuations in pulmonary NPVs indicated there was a pattern corresponding to structural and functional changes that occur during the terminal stage of pre-natal canine development and hence can be a useful diagnostic tool in veterinary. Foetal lung and liver SWVs were relatively consistent and there was no detectable changes during the pre-partum period for this variable or in echotexture.

Role of acoustic radiation force impulse imaging elastography in the assessment of steatohepatitis and fibrosis in rat models

Acoustic radiation force impulse (ARFI) elastography is a non-invasive method for performing liver assessment via liver shear wave velocity (SWV) measurements. The aim of this study was to evaluate the performance of the ARFI technique in the diagnosis of nonalcoholic steatohepatitis (NASH) and fibrosis and to investigate the effect of steatosis and inflammation on liver fibrosis SWV measurements in a rat model of nonalcoholic fatty liver disease (NAFLD). The ex vivo right liver lobes from 110 rats were processed and embedded in a fabricated gelatin phantom, and the other lobes were used for histologic assessment. The SWV induced by acoustic radiation force was derived to evaluate liver stiffness. The experimental results showed that the liver SWV value could be used to differentiate non-NASH rats from NASH-presenting rats and NASH from cirrhosis, and these comparisons showed areas under the receiver operating characteristic curves (AUROC) of 0.951 and 0.980, respectively. The diagnostic performances of ARFI elastography in predicting severe fibrosis (F ≥ 3) and cirrhosis (F ≥ 4) showed AUROC values of 0.997 and 0.993, respectively. In rats with mild fibrosis (F0–F1), severe steatosis had a significant effect on the mean SWV values. In rats with significant fibrosis (F2–F4), severe lobular inflammation had significant effects on the mean SWV values. Our findings indicate that ARFI elastography is a promising method for differentiating non-NASH rats from NASH rats and for staging hepatic fibrosis in NASH. The presence of severe steatosis and severe lobular inflammation are significant factors for evaluating fibrosis stages.

Validation of a sample preparation system (eFlow) for semen analysis in the AndroVision® CASA-System

Objective was to evaluate the echotexture and characteristics during terminal development of canine foetal respiratory and hepatic systems through elastographic examinations. Fifteen pregnant bitches were evaluated by ultrasonography twice daily, from the 53rd gestational day until whelping, and images obtained from 120 to 0 h before parturition were analysed. Images of foetal lungs and liver were recorded and then used for computer-assisted analyses to determine quantitative attributes. Acoustic Radiation Force Impulse (ARFI) elastographic of internal organs were classified as ‘soft’ (white areas) or ‘hard’ (dark areas) and quantitative analyses determined the mean shear wave velocities (SWV) of foetal lungs and liver. After delivery, canine neonates were clinically evaluated, and their health status was monitored weekly until 60 days post-partum. Sonographic parameters over time were compared by ANOVA and Pearson’s correlations were used to determine associations between SWVs and echotextural variables. Foetal lungs and liver had a homogeneous echotexture and pulmonary parenchyma appeared hyperechoic when compared with that of the liver. Mean numerical pixel values (NPVs) of lungs decreased from 120 to 24 h and subsequently increased until parturition (P = 0.04). Lungs and liver mean (± SD) SWVs (0.98 ± 0.12 and 0.84 ± 0.11 m/s, respectively) didn’t vary (P > 0.05) over time. Fluctuations in pulmonary NPVs indicated there was a pattern corresponding to structural and functional changes that occur during the terminal stage of pre-natal canine development and hence can be a useful diagnostic tool in veterinary. Foetal lung and liver SWVs were relatively consistent and there was no detectable changes during the pre-partum period for this variable or in echotexture.

Reducing the Number of Measurements in Liver Point Shear-Wave Elastography: Factors that Influence the Number and Reliability of Measurements in Assessment of Liver Fibrosis in Clinical Practice.

Purpose To identify the minimum number of measurements required for the noninvasive assessment of liver fibrosis by using point shear-wave elastography (pSWE) and determine whether the use of a reliability indicator such as interquartile range [IQR]-to-median ratio will affect diagnostic performance. Materials and Methods Ten liver shear-wave velocity (SWV) measurements by pSWE were obtained in 232 participants. Interclass correlation coefficients (ICC) between the median of the first two through the first nine measurements and all 10 measurements were calculated; the minimum number of measurements with ICC greater than 0.95 versus all 10 measurements was determined. The diagnostic performance of the minimum number of measurements and 10 measurements in identifying significant (Ishak stage, ≥3) and severe fibrosis or cirrhosis (Ishak stage, ≥5) was compared by using areas under the receiver operating characteristic curve. These were compared between measurements that demonstrated higher or lower reliability (IQR-to-median ratio of ≤ 30% and IQR-to-median ratio of > 30%, respectively). Results Compared with 10 measurements, a minimum of six SWV measurements was required. The overall area under the curve for diagnosing significant (areas under the receiver operating characteristic curve, 0.828 vs 0.839; P = .487) and severe fibrosis or cirrhosis (0.953 vs 0.969, respectively; P = .145) did not differ according to number of measurements (six vs 10); a median of six measurements resulted in only limited disagreement (nine of 232 [3.9%]) versus histologic evaluation. When using 10 measurements, higher reliability measurements showed a lower percentage of discordance between pSWE and significant fibrosis and severe fibrosis or cirrhosis (22 [14.7%] and three [2.0%] of 150 cases, respectively) compared with lower reliability measurements (26 [31.7%] and eight [9.8%] of 82 cases, respectively). Significant fibrosis was an independent predictor for lower reliability (hazard ratio, 2.22; P < .020). Conclusion A limited number of SWV measurements (median six vs median 10) were required for the assessment of liver fibrosis by using pSWE. The number of measurements had less influence on the diagnostic accuracy compared with lower reliability measurements. © RSNA, 2018 Online supplemental material is available for this article.

Noninvasive assessment of hepatic sinusoidal obstructive syndrome using acoustic radiation force impulse elastography imaging: A proof-of-concept study in rat models.

To determine the feasibility of acoustic radiation force impulse (ARFI) elastography in the evaluation of hepatic sinusoidal obstruction syndrome (SOS) in rat models. Rat SOS models of various severities were created by monocrotaline gavage (n = 40) or by intraperitoneal injection of 5-fluorouracil, leucovorin and oxaliplatin (FOLFOX) (n = 16). Liver shear-wave velocity (SWV) was measured using ARFI elastography. Liver samples were analysed for the SOS score, steatosis, lobular inflammation and fibrosis. The liver SWV was significantly elevated in the SOS models (1.29-2.24 m/s) compared with that of the matched control rats (1.01-1.09; p≤.09; veFor seven FOLFOX-treated rats which were longitudinally followed-up, the liver SWV significantly increased at 7 weeks (1.32±0.13 m/s) compared with the baseline (1.08±0.1 m/s, p=.015) and then significantly declined after a 2-week, treatment-free period (1.15±0.13 m/s; p=.048). Multivariate analysis revealed that the SOS score (p<.001) and lobular inflammation (p=.044) were independently correlated with the liver SWV. Liver SWV is elevated in SOS in proportion to the degree of sinusoidal injury and lobular inflammation in rat SOS models. ARFI elastography has potential as an examination for diagnosis, severity assessment and follow-up of SOS. • Liver SWV using ARFI elastography was significantly elevated in SOS rat. • Sinusoidal injury and lobular inflammation grades had correlation with liver SWV. • ARFI elastography has potential for diagnosis, severity assessment, and follow-up of SOS.

Improved Shear Wave Group Velocity Estimation Method Based on Spatiotemporal Peak and Thresholding Motion Search.

Quantitative ultrasound elastography is increasingly being used in the assessment of chronic liver disease. Many studies have reported ranges of liver shear wave velocity values for healthy individuals and patients with different stages of liver fibrosis. Nonetheless, ongoing efforts exist to stabilize quantitative ultrasound elastography measurements by assessing factors that influence tissue shear wave velocity values, such as food intake, body mass index, ultrasound scanners, scanning protocols, and ultrasound image quality. Time-to-peak (TTP) methods have been routinely used to measure the shear wave velocity. However, there is still a need for methods that can provide robust shear wave velocity estimation in the presence of noisy motion data. The conventional TTP algorithm is limited to searching for the maximum motion in time profiles at different spatial locations. In this paper, two modified shear wave speed estimation algorithms are proposed. The first method searches for the maximum motion in both space and time [spatiotemporal peak (STP)]; the second method applies an amplitude filter [spatiotemporal thresholding (STTH)] to select points with motion amplitude higher than a threshold for shear wave group velocity estimation. The two proposed methods (STP and STTH) showed higher precision in shear wave velocity estimates compared with TTP in phantom. Moreover, in a cohort of 14 healthy subjects, STP and STTH methods improved both the shear wave velocity measurement precision and the success rate of the measurement compared with conventional TTP.

Ex vivo study of acoustic radiation force impulse imaging elastography for evaluation of rat liver with steatosis

Nonalcoholic fatty liver disease (NAFLD) is one of the most common liver diseases in developed countries. Accurate, noninvasive tests for diagnosing NAFLD are urgently needed. The goals of this study were to evaluate the utility of acoustic radiation force impulse (ARFI) elastography for determining the severity grade of steatosis in rat livers, and to investigate the changes in various histologic and biochemical characteristics. Steatosis was induced in the livers of 57 rats by gavage feeding of a high fat emulsion; 12 rats received a standard diet only and served as controls. Liver mechanics were measured ex vivo using shear wave velocity (SWV) induced by acoustic radiation force. The measured mean values of liver SWV ranged from 1.33 to 3.85m/s for different grades of steatosis. The area under the receiver operative characteristic curve (⩾S1) was equal to 0.82 (95% CI=0.69, 0.96) between the steatosis group and the normal group, and the optimal cutoff value was 2.59 with sensitivity of 88% and specificity of 76%. However, there are no significant differences in SWV measurements between the steatosis grades. SWV values did not correlate with the early grade of inflammation. In conclusion, ARFI elastography is a promising method for differentiating normal rat liver from rat liver with steatosis, but it cannot reliably predict the grade of steatosis in rat livers. The early grade of inflammation activity did not significantly affect the SWV measurements.

The influence of acute physical effort on liver stiffness estimation using Virtual Touch Quantification (VTQ). Preliminary results.

Food intake and acutely decompensated cardiac failure may impair liver stiffness estimations, mainly because these methods are influenced by liver blood flow variation encountered in these conditions. It is well known that also during physical effort liver blood flow changes, due to the redistribution of blood flow mainly to the skeletal muscles. The aim of this study is to assess the change of liver shear- wave velocities immediately after cessation of an acute physical effort. A secondary aim was to find the proper timing for accurate liver stiffness estimation after physical exhaustion. Liver shear-wave velocities were measured using virtual touch quantification (VTQ) in seven apparently healthy volunteers, in fasting conditions. All subjects underwent a complete abdominal ultrasound study, including the liver VTQ. Then, all subjects performed a spiroergometry and thereafter, another series of three liver shear-wave velocity measurements were performed: immediately after spiroergometry, five min, and ten min after spiroergometry, respectively. Before spiroergoemetry, the mean liver shear-wave velocity was 1.05+/-0.12 m/sec. Immediately after spiroergometry, mean liver shear-wave velocities increased significantly, measuring 1.34+/-0.16 m/sec (p <0.01). The mean liver shear-wave velocities at five and ten minutes after exhausting were 1.23+/-0.14 m/sec and 1.05+/-0.11 m/sec respectively. Liver stiffness estimation using VTQ was influenced by acute physical exercise in our study group. Despite the small number of subjects, the preliminary results show that if patients had done physical effort before VTQ elastography, they should rest at least ten minutes before reliable liver stiffness estimations can be performed.

Comparison of FibroTouch and acoustic radiation force impulse in diagnosis of liver fibrosis in patients with chronic hepatitis B

Objective: To compare transient elastorgaphy (FibroTouch) and acoustic radiation force impulse (ARFI) in diagnosis of liver fibrosis in patients with chronic hepatitis B. Methods: One hundred and forty five patients with chronic hepatitis B underwent FibroTouch and ARFI examinations in Xixi Hospital of Hangzhou from January to November 2015. The liver stiffness (LSM) was detected by FibroTouch and the liver shear wave velocity (VTQ) was detected by ARFI; liver biopsy was performed in all patients. With biopsy results as gold standards, the diagnostic values of FibroTouch and ARFI for liver fibrosis were analyzed with Spearman correlation analysis and receiver operating characteristic (ROC) curve. Results: The correlation coefficient of FibroTouch and ARFI was 0.746 (P<0.01). FibroTouch and ARFI were significantly correlated with pathological stage determined by liver biopsy(r=0.705 and 0.727, all P<0.01). When 8.4 kPa was taken as the cut-off value of LSM and 1.49 m/s was taken as the cut-off value of VTQ, the areas under ROC (AUCs) were 0.857 and 0.836 (P>0.05) in diagnosis of fibrosis S≥2 stage; when 10.8 kPa of LSM and 1.49 m/s of VTQ were used as cut-off values, the AUCs were 0.872 and 0.881 (P>0.05) in diagnosis of S≥3 stage; when 12.3 kPa of LSM and 1.81m/s of VTQ were used as cut-off values, the AUCs were 0.875 and 0.888 (P>0.05) in diagnosis of S=4 stage. Conclusion: Both FibroTouch and ARFI can be effectively used in evaluation of liver fibrosis in patients with chronic hepatitis B.

Liver Shear-Wave Velocity and Serum Fibrosis Markers to Diagnose Hepatic Fibrosis in Patients with Chronic Viral Hepatitis B.

ObjectiveTo compare several noninvasive indices of fibrosis in chronic viral hepatitis B, including liver shear-wave velocity (SWV), hyaluronic acid (HA), collagen type IV (CIV), procollagen type III (PCIII), and laminin (LN).Materials and MethodsAcoustic radiation force impulse (ARFI) was performed in 157 patients with chronic viral hepatitis B and in 30 healthy volunteers to measure hepatic SWV (m/s) in a prospective study. Serum markers were acquired on the morning of the same day of the ARFI evaluation. Receiver operating characteristic (ROC) analysis was performed to evaluate and compare the accuracies of SWV and serum markers using METAVIR scoring from liver biopsy as a reference standard.ResultsThe most accurate test for diagnosing fibrosis F ≥ 1 was SWV with the area under the ROC curve (AUC) of 0.913, followed by LN (0.744), HA (0.701), CIV (0.690), and PCIII (0.524). The best test for diagnosing F ≥ 2 was SWV (AUC of 0.851), followed by CIV (0.671), HA (0.668), LN (0.562), and PCIII (0.550). The best test for diagnosing F ≥ 3 was SWV (0.854), followed by CIV (0.693), HA (0.675), PCIII (0.591), and LN (0.548). The best test for diagnosing F = 4 was SWV (0.965), followed by CIV (0.804), PCIII (0.752), HA (0.744), and LN (0.662). SWV combined with HA and CIV did not improve diagnostic accuracy (AUC = 0.931 for F ≥ 1, 0.863 for F ≥ 2, 0.855 for F ≥ 3, 0.960 for F = 4).ConclusionThe performance of SWV in diagnosing liver fibrosis is superior to that of serum markers. However, the combination of SWV, HA, and CIV does not increase the accuracy of diagnosing liver fibrosis and cirrhosis.

Acoustic radiation force impulse imaging in paediatric patients: normal liver values.

The objective of this study was to obtain a normal value for liver shear wave velocities (SWVs) in healthy paediatric patients and to investigate variations concerning age, sex, and different approaches, depths, and lobes of measurements. A total of 150 healthy children (2 months-17 years) were examined with acoustic radiation force impulse (ARFI) technology by an experienced paediatric radiologist, after receiving an informed consent. Measurements obtained were divided according to group age (n = 50, 0-5 years; n = 50, 6-11 years; n = 50, 12-17 years); sex (male-female); lobe (right-left lobe); approach (intercostal-subcostal), and depth of measurements (1-5 and 5-6 cm for the youngest group; 2-6 to 6-8 cm for the 2 other groups). Comparative analyses were performed with measurements obtained at right and left lobes, with different depths and approaches. Differences between age and sex were also analysed. Mean SWV in the right liver lobe was 1.07 ± 0.10 m/s. No significant differences were found according to sex or among different probe locations. SWVs were, however, significantly higher within left lobe in comparison with right liver lobe (1.07 ± 0.10 m/s, right; 1.21 ± 0.16 m/s, left). Depth of measurements also influenced SWV values obtained, being slightly lower at deeper locations. Regarding the age significant differences were found for children <6 years old compared with other age groups. ARFI analysis seems to be influenced by age, depth, and lobe of measurements. A mean SWV value of 1.07 ± 0.10 m/s for healthy paediatric population with the possibility of reaching 1.12 m/s in the case of younger children was found. ARFI values were more consistently obtained analysing right liver lobe and depths lower than 5 to 6 cm.

Normal Values of Liver Shear Wave Velocity in Healthy Children Assessed by Acoustic Radiation Force Impulse Imaging Using a Convex Probe and a Linear Probe

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