Reply to: “New imaging assisted methods for liver fibrosis quantification: Is it really favorable to classical transient elastography?”
Authors: Christophe Cassinotto, Victor de Lédinghen
Journal: Journal of Hepatology (2015)

Non-invasive assessment of liver fibrosis with impulse elastography: Comparison of Supersonic Shear Imaging with ARFI and FibroScan®Journal of HepatologyVol. 61Issue 3PreviewNon-invasive assessment of liver fibrosis by elastography is a rapidly developing field with frequent technological innovations. The aim of this study was to assess the diagnostic performances of Supersonic Shear Imaging (SSI) for the diagnosis of liver fibrosis in chronic liver disease. Full-Text PDF New imaging assisted methods for liver fibrosis quantification: Is it really favorable to classical transient elastography?Journal of HepatologyVol. 63Issue 3PreviewNon-invasive evaluation of liver fibrosis is now an inescapable tool for patient assessment and follow-up in fibrotic diseases such as hepatitis B or C, but also in alcoholic liver disease (ALD) or non-alcoholic fatty liver disease (NAFLD). Full-Text PDF Open Access Non-invasive assessment of liver fibrosis with impulse elastography: Comparison of Supersonic Shear Imaging with ARFI and FibroScan. We read with great interest comments by Dr. Lanthier et al. [[1]Lanthier N. Stärkel P. Horsmans Y. New imaging assisted methods for liver fibrosis quantification: is it really favorable to classical transient elastography?.J Hepatol. 2015; 63: 765-766https://doi.org/10.1016/j.jhep.2015.04.027Abstract Full Text Full Text PDF PubMed Scopus (5) Google Scholar] regarding our article published in Journal of Hepatology [[2]Cassinotto C. Lapuyade B. Mouries A. Hiriart J.B. Vergniol J. Gaye D. et al.Non-invasive assessment of liver fibrosis with impulse elastography: comparison of Supersonic Shear Imaging with ARFI and FibroScan.J Hepatol. 2014; 61: 550-557https://doi.org/10.1016/j.jhep.2014.04.044Abstract Full Text Full Text PDF PubMed Scopus (257) Google Scholar]. We thank the authors for their kind interest in our work and welcome the opportunity to clarify points they raised. First, in our study we did not apply nor even mention reliability criteria regarding the Supersonic Shear Imaging (SSI) technique. As Dr. Lanthier said, SSI is quite a recent technique, and to date, no study has focused on the description or definition of reliability criteria for this technique. In our study, interquartile range (IQR)/liver stiffness measurement (LSM) was <0.10 in 207 patients (69%), between 0.10 and 0.30 in 91 (30%), and >0.30 in 3 patients (1%). So, it is quite obvious that the reliability criteria of FibroScan® are probably not applicable to SSI, but we believe that the definition of such criteria requires a large multicentre study and should not be performed too hastily in a single centre study. Second, we’d like to clarify the key point that the failure rate of FibroScan® in our study is low, around 2.6%, because the XL probe was used for obese patients (i.e. with body mass index ⩾30 kg/m2) (30% of patients of our study). In our experience, the failure rate of SSI is very close to that of the M probe of FibroScan®. Indeed, we can notice that the failure rate of SSI in our study (10.4% in the whole population; 28% for obese patients but only 2.6% for others) is close to the failure rate of the M probe described in the study by de Lédinghen et al. [[3]de Lédinghen V. Wong V.W. Vergniol J. Wong G.L. Foucher J. Chu S.H. et al.Diagnosis of liver fibrosis and cirrhosis using liver stiffness measurement: comparison between M and XL probe of FibroScan.J Hepatol. 2012; 56: 833-839https://doi.org/10.1016/j.jhep.2011Abstract Full Text Full Text PDF PubMed Scopus (182) Google Scholar] among a patient population quite representative of our study population although with a slightly lower BMI (8.4% in the whole population; 26% for obese patients but only 2.5% for others). Unfortunately, as for ARFI and FibroScan®, the reliability of liver stiffness measurement with SSI is dependant on the quality of the shear wave transmission, which rapidly decreases as weight increases. This is likely to be evident in SSI and ARFI techniques where operators can notice the strong relationship between the reliability of the LSM and the quality of the spatial resolution on the B-mode US image. Finally, as we’ve discussed, we agree that further studies are needed assessing the diagnostic performances and limits of SSI in specific aetiologies of chronic liver diseases. However, there is mounting evidence that SSI should be considered as an accurate and promising elastography technique in the field of chronic liver diseases. To conclude, we are living in an era of great and frequent technological innovations, which is particularly exciting, but we have the duty to analyse, criticize and finally validate as quick as possible each new progress in order to ultimately provide the best diagnosis and treatment for all patients. These authors have declared they have nothing to disclose regarding funding and conflict of interest with respect to this manuscript.