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To evaluate liver stiffness measurements success rates (SR) by pSWE and 2D-SWE implemented on different ultrasound probes from different vendors and evaluate the input on the success rate of a new bariatric probe (DAX) in obese patients. A prospective study was conducted in which liver stiffness measurements (LSM) were performed in 201 consecutive subjects (60.1% men, average BMI = 28.7 ± 4.9 kg/m2, average age 59 ± 18.4 years, 38% obese) with or without chronic hepatopathies evaluated during the same session by point Shear Wave Elastography (pSWE), 2D Shear Wave Elastography (2D SWE), and Transient Elastography (TE) implemented on the following systems: Siemens ACUSON Sequoia (5C-1 convex transducer with pSWE and 2D SWE, Deep Abdominal Transducer (DAX) with pSWE and 2D SWE, 4V-1 linear transducer with pSWE), Aixplorer Mach 30 (C6-1X convex transducer with 2D SWE) and FibroScan Compact 530 (M and XL probes). Reliable LS measurements were defined as the median value of 10 measurements and an IQR/M<0.3. Valid LSM were obtained in 99%(199/201) using TE, 99%(199/201) using 2D SWE (C6-1X), 98.5% (198/201) using 2D SWE (5C-1), 99%(199/201) using 2D SWE (DAX), 97.5%(196/201) using pSWE (5C-1), 97.5%(196/201) using pSWE (DAX) and 91.5% (184/201) using pSWE (4V-1). No significant difference were found between the SR of TE, 2D SWE using C6-1X, 5C-1, DAX and pSWE using C5-1 and DAX (p>0.05. pSWE using the linear probe 4V-1 had significantly lower SR compared to the other probes (p< 0.001). 38% (77/201) of subjects were obese. Valid LSM were obtained in 100% of the obese (77/77) using 2D SWE DAX, in 98.7% (76/77) using TE, 2D SWE C6-1X, and pSWE DAX, in 97.4% (75/77) using pSWE and 2D SWE 5C-1 and in 83.1% (64/77) using pSWE 4V-1. No significant differences were found between the SR of TE, 2D SWE using C6-1X, 5C-1, DAX and pSWE using C5-1 and DAX in obese subjects (p>0.05). pSWE using the linear probe 4V-1 had significantly lower SR compared to the other probes in obese subjects (p<0.001). 2D SWE and pSWE implemented on convex ultrasound probes have very high success rates for liver stiffness measurements in general population and in obese, with no significant differences between them. pSWE implemented on 4V-1 linear ultrasound probe has a significantly lower success rate for liver stiffness measurements compared to pSWE and 2D SWE implemented on convex ultrasound probes. 2D SWE DAX probe had the highest SR (100%) in obese, with no significant differences compared to the other 2D SWE and pSWE implemented on convex ultrasound probes. [ABSTRACT FROM AUTHOR]

Liver fibrosis is the most significant prognostic factor in chronic liver disease (CLD). Clinical practice guidelines recommend the use of non-invasive techniques, such as two-dimensional shear-wave elastography (2D-SWE), to assess liver elasticity as a marker of fibrosis. It is presumed that changes due to necro-inflammation modify the propagation of shear waves [1]. Therefore, new imaging techniques that investigate the dispersion properties of shear waves have been developed, which can serve as an indirect method of measuring liver viscosity (Vi PLUS). This study aims to analyze the performance of SWE to assess viscosity, to analyze factors influencing Vi PLUS measurements in a large cohort of patients with CLD, and to assess the normal ranges of liver viscosity measurements in participants with healthy livers. 867 consecutive adult subjects were enrolled in this prospective study (199 with healthy livers and 668 with CLD). Subjects were first examined using the Supersonic MACH® 30 US system (Hologic® SuperSonic® Imagine, Aix-en-Provence, France). Gray-scale US, as well as 2D-SWE and Vi PLUS measurements were performed. Secondly, TE measurements were performed with a FibroScan® Compact 530 device (EchoSens®, Paris, France). The mean Vi PLUS values in normal, ALD, HBV, HCV, NAFLD patients were: 1.6±0.3 Pa·s, 2.8±0.8 Pa·s, 1.9±0.3 Pa·s, 2.1±0.5 Pa·s and 2±0.4 Pa·s respectively (table 1). The mean Vi PLUS values were significantly higher in subjects with chronic liver disease than in normal subjects, independent of the etiology (p>0.05). Mean Vi PLUS values were significantly higher in subjects with ALD compared to HCV (p<0.0001), HBV (p<0.0001) and NAFLD subjects (p<0.0001); significantly higher in subjects with HCV compared to HBV (p=0.0001) and NAFLD subjects (p=0.011). No significant differences were found between HBV and NAFLD subjects (p=0.0615). In univariate regression analysis, Vi PLUS measurements were independently associated with: BMI (p<0.001), abdominal circumference (p<0.001), age (p<0.001), AST (p<0.001), ALT (p=0.009), the presence of diabetes mellitus (p<0.0001) and the presence of arterial hypertension (p<0.001). In multiple regression analysis the model including: abdominal circumference (p<0.0001), AST (p<0.0001) and ALT values (p=0.0029) was associated with ViPLUS measurements. Vi PLUS and 2D-SWE by SSI are highly feasible methods. The mean liver viscosity determined by Vi PLUS in our cohort of participants with healthy livers was 1.69 Pa·s. CLD patients had significantly higher viscosity values. Increased liver stiffness, high transaminases and obesity were associated with high viscosity values. [ABSTRACT FROM AUTHOR]

Abstract: Background: Acoustic Radiation Force Impulse Elastography is a new method for non-invasive evaluation of liver fibrosis. Aim: To evaluate the impact of elevated alanine aminotransferase levels on liver stiffness assessment by Acoustic Radiation Force Impulse Elastography. Methods: A multicentre retrospective study including 1242 patients with chronic liver disease, who underwent liver biopsy and Acoustic Radiation Force Impulse. Transient Elastography was also performed in 512 patients. Results: The best Acoustic Radiation Force Impulse cut-off for predicting significant fibrosis was 1.29m/s in cases with normal alanine aminotransferase levels and 1.44m/s in patients with alanine aminotransferase levels>5× the upper limit of normal. The best cut-off for predicting liver cirrhosis were 1.59 and 1.75m/s, respectively. Acoustic Radiation Force Impulse cut-off for predicting significant fibrosis and cirrhosis were relatively similar in patients with normal alanine aminotransferase and in those with alanine aminotransferase levels between 1.1 and 5× the upper limit of normal: 1.29m/s vs. 1.36m/s and 1.59m/s vs. 1.57m/s, respectively. For predicting cirrhosis, the Transient Elastography cut-offs were significantly higher in patients with alanine aminotransferase levels between 1.1 and 5× the upper limit of normal compared to those with normal alanine aminotransferase: 12.3kPa vs. 9.1kPa. Conclusion: Liver stiffness values assessed by Acoustic Radiation Force Impulse and Transient Elastography are influenced by high aminotransferase levels. Transient Elastography was also influenced by moderately elevated aminotransferase levels. [Copyright &y& Elsevier]

Abstract: We used supersonic shear imaging to determine the liver stiffness (LS) values of 82 patients without known liver pathology and studied the factors that influence these measurements. Five LS measurements were made in each subject, and the median value, expressed in kilopascals, was calculated. Reliable LS measurements were obtained in 84.5% of patients. Higher body mass index and older age were associated with failure to obtain reliable measurements. The mean value of LS measurements determined by SSI in our cohort of patients without known liver pathology was 6 ± 1.4 kPa. The mean LS measurements determined by SSI for men were significantly higher than those for women; body mass index did not significantly influence SSI measurements. Thus, 6 kPa is the mean SSI value in patients without known liver pathology, with higher values being obtained in men. [Copyright &y& Elsevier]

Abstract: Our aim was to compare liver stiffness (LS) measurements by means of acoustic radiation force impulse (ARFI) elastography and transient elastography (TE) in patients with chronic hepatitis B and C, according to the severity of fibrosis. We also compared the correlation strength of ARFI and TE measurements with liver fibrosis. We included 53 patients with hepatitis B and 107 with hepatitis C in which liver biopsy, ARFI and TE measurements were performed in the same session. The mean LS values measured with ARFI were similar in patients with chronic hepatitis B and C and depended on the stage of fibrosis. The correlation strength of LS measurements by ARFI and by TE with fibrosis was similar in chronic hepatitis B and C patients. In conclusion, for the same stage of fibrosis, the mean LS values by ARFI were similar in patients with chronic hepatitis B and C. ARFI had similar predictive value with TE in both chronic viral hepatitis. [Copyright &y& Elsevier]

In the current literature, there is only a small number of studies that have evaluated the utility of point share wave elastography for pancreatic assessment. To assess the feasibility of Virtual Touch Quantification (VTQ) elastography for pancreas assessment, as well as the mean pancreatic stiffness values in healthy subjects. We included 70 subjects (52.8% women, 47.2% men, average BMI = 25.9 ± 4.9 kg/m2, average age 46.8 ± 18.4 years) with a normal pancreatic ultrasound aspect and with no history of pancreatic disease or diabetes, in whom elastography measurements were performed with a Siemens Acuson S2000 Virtual Touch ultrasound system (Siemens AG, Erlangen, Germany) using a 4CI transducer. For each patient, 10 valid VTQ measurements of the pancreatic parenchyma were performed under fasting conditions. Reliable measurements were defined as a median value of ten pancreas stiffness measurements with a success rate ≥ 60% and an interquartile range interval < 30%. Out of 70 subjects, reliable measurements were acquired in 61 subjects (87.1%) by means of VTQ elastography. The mean pancreas stiffness values in healthy subjects was 1.26 m/s ± 0.1 m/s, CI 95% (1.24-1.28). There were no significant differences between the mean pancreas stiffness in men vs. women 1.25 m/s ± 0.09 m/s, CI 95% (1.21-1.28) vs. 1.28 m/s ± 0.1 m/s CI 95% (1.25-1.31) (p = 0.103). VTQ can be a useful tool for pancreas quantification characterized by a good feasibility (87.1%) in healthy subjects. The mean pancreas stiffness values in healthy individuals was 1.26 m/s ± 0.1m/s. [ABSTRACT FROM AUTHOR]