Quantification of Steatosis and Fibrosis using a new system implemented in an ultrasound machine

Abstract

Aim: The study compared the usefulness of 2D-SWE and attenuation measurements obtained using Aplio i800 from Canon together with Transient Elastography (TE) and the Controlled Attenuation Parameter (CAP) as the reference method.Material and methods: We included 112 consecutive adults with reliable LS measurements, 44 healthy subjects and 68 subjects with chronic hepatopathies in whom liver stiffness (LS) and steatosis were evaluated in the same session employing two elastography techniques: Transient Elastography (TE) with Controlled Attenuation Parameter (CAP) implemented on the FibroScan® 530 Compact system and Two Dimensional Shear Wave Elastography (2D-SWE) with Attenuation Imaging (ATI) installed on the Aplio i800 series ultrasound system. Reliable measurements were defined as the median value of 10, respectively 5 valid LS measurements for TE and 2D-SWE, with an interquartile range interval/median ratio (IQR/M) <30%.Results: A very strong positive correlation was found between LS values obtained by TE and 2D-SWE: r=0.88, p<0.0001 and between the attenuation coefficients of steatosis obtained by CAP and ATI, r=0.81, p<0.0001. The best cut-off values by 2DSWE for predicting different stages of liver fibrosis were: for F≥2 - 7.9 kPa and F=4 - 11.7 kPa. Regarding steatosis, the best ATI cut-off values were: for S≥1 - 0.79 dB/cm/mHz and for S3 - 0.86 dB/cm/mHz.Conclusion: 2D-SWE and ATI measurements with the new system strongly correlated with TE and CAP results.

Complex ultrasound evaluation of non-alcoholic fatty liver disease. “One stop shop” with new ultrasound-based techniques.

“…Nonalcoholic fatty liver disease (NAFLD) is currently a major health problem, affecting more than onequarter of adults in the world, 60% of diabetic patients and 90% of obese people having this condition [1]. The spectrum of NAFLD covers a wide histological variety from non-evolutive simple steatosis to progressive nonalcoholic steatohepatitis (NASH), which may progress to liver cirrhosis, hepatic failure and hepatocellular carcinoma (HCC) [1][2][3]. Patients with NAFLD experience a high risk of death from cardiovascular disease but also from end stage liver disease and HCC [1][2][3][4].…”

“…The spectrum of NAFLD covers a wide histological variety from non-evolutive simple steatosis to progressive nonalcoholic steatohepatitis (NASH), which may progress to liver cirrhosis, hepatic failure and hepatocellular carcinoma (HCC) [1][2][3]. Patients with NAFLD experience a high risk of death from cardiovascular disease but also from end stage liver disease and HCC [1][2][3][4]. The risk increases significantly among patients with NASH and fibrosis [4].…”

“…Thus, key issues in NAFLD patients are the differentiation of NASH from simple steatosis and identification of advanced hepatic fibrosis. Liver biopsy has been the gold standard to differentiate simple steatosis from steatohepatitis with or without fibrosis [1][2][3][4]. However, it is an invasive diagnostic tool associated with rare but potentially life-threatening complications, has a poor acceptability which is relevant in such a big population, has sampling variability and is not suitable for follow up [3].…”

“…It has become obvious that in clinical practice for identifying NAFLD, it is preferable to use effective noninvasive methods for tracking disease processes and monitoring treatment effects [1][2][3]. Ultrasound (US) was the first-line imaging test used in clinical practice in individuals with suspected NAFLD [1].…”

“…Moreover, it cannot diagnose fibrosis and steatohepatitis, very important pathologic stages toward a severe liver disease. Another limitation of US is the impossibility to monitor disease progression and to assess various therapeutical methods [1,2,5,6]. Recent studies obtained better results using quantitative ultrasound (sonographic hepatorenal index, hepatic attenuation rate, Steatoscore, acoustic structure quantification [3][4][5]).…”