New imaging assisted methods for liver fibrosis quantification: Is it really favorable to classical transient elastography?
Authors: Nicolas Lanthier, Peter Stärkel, Yves Horsmans
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 Reply to: "New imaging assisted methods for liver fibrosis quantification: Is it really favorable to classical transient elastography?"Journal of HepatologyVol. 63Issue 3PreviewNon-invasive assessment of liver fibrosis with impulse elastography: Comparison of Supersonic Shear Imaging with ARFI and FibroScan. Full-Text PDF Open Access Non-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). The gold standard liver biopsy carries risks and could be considered as an aggressive method compared to non-invasive investigations. Liver biopsy has been challenged by low reproducibility in blinded histological comparison studies [[1]Bedossa P. Dargere D. Paradis V. Sampling variability of liver fibrosis in chronic hepatitis C.Hepatology. 2003; 38: 1449-1457Crossref PubMed Scopus (2060) Google Scholar] and a larger liver parenchyma analysis compared to the limited microscopic analysis of a liver fragment is potentially attractive. Taken together, these data support the utilization and the development of non-invasive techniques for liver fibrosis quantification replacing or in addition to liver biopsy. Direct or indirect serum markers, as well as panels of markers show low areas under the receiver operating curves for fibrosis determination [[2]Adams L.A. Biomarkers of liver fibrosis.J Gastroenterol Hepatol. 2011; 26: 802-809Crossref PubMed Scopus (82) Google Scholar]. By contrast, transient elastography (FibroScan®), one of the first (developed in 2003) [[3]Sandrin L. Fourquet B. Hasquenoph J.M. Yon S. Fournier C. Mal F. et al.Transient elastography: a new noninvasive method for assessment of hepatic fibrosis.Ultrasound Med Biol. 2003; 29: 1705-1713Abstract Full Text Full Text PDF PubMed Scopus (2288) Google Scholar] in vivo methods directly evaluating liver stiffness, presents an acceptable profile with cut-offs being validated principally in the setting of liver fibrosis due to chronic hepatitis C but also for liver cirrhosis of other various etiologies [[4]Tsochatzis E.A. Gurusamy K.S. Ntaoula S. Cholongitas E. Davidson B.R. Burroughs A.K. Elastography for the diagnosis of severity of fibrosis in chronic liver disease: a meta-analysis of diagnostic accuracy.J Hepatol. 2011; 54: 650-659Abstract Full Text Full Text PDF PubMed Scopus (615) Google Scholar]. New imaging techniques were further developed, including acoustic radiation force impulse (ARFI) in 2009 and more recently in 2011 supersonic shear wave imaging (SSI). Both techniques allow the selection of the surface of interest (through a coupled standard 2D ultrasound image) to perform fibrosis quantification. In a recent paper published in the Journal, Cassinotto et al. compared SSI to histological fibrosis score, ARFI and FibroScan® in 349 patients [[5]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(R).J Hepatol. 2014; 61: 550-557Abstract Full Text Full Text PDF PubMed Scopus (280) Google Scholar]. The authors conclude that "SSI is an efficient method for liver fibrosis assessment in chronic liver diseases, comparing favorably to FibroScan®". We would like to comment on data interpretation and conclusions. First, in the methods, criteria were given for unreliable results only for FibroScan® (10 valid measurements, 20 maximum attempts number and interquartile range/liver stiffness measurement ⩽0.3) and ARFI (interquartile range/liver stiffness measurement ⩽0.3). For both techniques, the result is given as the median of all values. No criteria for reliable data with SSI was neither presented nor applied. Three measurements were used with this last technique and the result is given as the mean value of them. The authors do not provide how many reliable or unreliable measurements were obtained nor do they propose an acceptable interquartile range for both measurements (interquartile range in one surface of interest) as well as for the three measurements. Second, a measurement failure rate of 10.4% with SSI is impressive compared with only 2.6% for FibroScan® and none for ARFI. Those SSI failures were more frequent in obese patients [[5]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(R).J Hepatol. 2014; 61: 550-557Abstract Full Text Full Text PDF PubMed Scopus (280) Google Scholar] which is surprising given the putative advantage of this new technique in this special population (allowing the choice of a surface of interest at a distance to the subcutaneous fat tissue) and constitutes a serious draw-back in the context of increasing prevalence of obesity. Third, as presented by the authors, in the analysis, SSI was superior to FibroScan® only for detection of severe fibrosis (fibrosis stage F3). Both techniques performed equally well for the F1, F2 or F4 determination. Finally, the study population in this trial is heterogeneous including many different disease etiologies. Concluding that SSI constitutes an efficient method in chronic liver diseases (which implies in all chronic diseases) is probably too premature since well designated studies for each special population (corresponding to one disease etiology) are lacking for this technique. The performance to evaluate liver fibrosis could be affected differently among techniques by several factors according to the etiology such as transaminases flares, liver steatosis or necroinflammation, high body mass index or hepatic congestion, known to cause potential stiffness overestimation using transient elastography [[6]Macaluso F.S. Maida M. Camma C. Cabibbo G. Cabibi D. Alduino R. et al.Steatosis affects the performance of liver stiffness measurement for fibrosis assessment in patients with genotype 1 chronic hepatitis C.J Hepatol. 2014; 61: 523-529Abstract Full Text Full Text PDF PubMed Scopus (66) Google Scholar]. In conclusion, in our view, these data are not sufficient for advocating the implementation of SSI in liver fibrosis determination in clinical practice. Furthermore, the finding that better fibrosis stage F3 detection is possible with this technique compared to FibroScan® has to be counterbalanced by the high liver stiffness failure rate observed with the technique. Well-designed prospective studies for specific disease etiologies are necessary which apply pre-determined validity criteria as well as including measurement failures in the results, the discussion and the data interpretation. The authors who have taken part in this study declared that they do not have anything to disclose regarding funding or conflict of interest with respect to this manuscript. NL (drafting of the manuscript), PS and YH (critical revision of the manuscript).