ElastP a novel elastographic method for the evaluation of liver fibrosis in patients with B and C chronic hepatopathies

Abstract

The purpose of this study was to evaluate the diagnostic performance of a point shear wave elastography using ARFI technique- ElastPQ, in patients with B and C chronic hepatopathies, using Transient Elastography (TE) as the reference method, since it is a validated method for liver fibrosis assessment. Materials and methods: The study included 228 consecutive subjects with chronic hepatopathies (26% HBV, 74% HCV) from whom 51% had liver cirrhosis. Liver stiffness (LS) was evaluated in the same session by means of 2 elastographic methods: TE (Fibroscan, Echosens) and ElastPQ (Philips, Affinity). Reliable LS measurements (LSM) were defined as follows: for TE – the median value of 10 LSM with a success rate≥60% and an interquartile range< 30%. For ElastPQ- the median value of 10 LSM in the liver parenchyma, at least 1 cm below the capsule, avoiding large vessels. For differentiating between stages of liver fibrosis we used the following cut-off values for TE – mild fibrosis (F1)-6.1 kPa, moderate fibrosis (F2)- 7.2 kPa, severe fibrosis (F3)-9.6 kPa and for liver cirrhosis (F4) -14.5kPa (1). Results: Reliable LSM were obtained in 90.7% (207/228) by means of TE and in 98.7% (225/228) with ElastPQ. In the final analysis 205 patients were included. The areas under the receiver operating characteristic curve for ElastPQ were: 0.90 for patients with mild fibrosis (F1), 0.95 for moderate fibrosis (F2), 0.96 for severe fibrosis (F3) and 0.94 for cirrhosis. The best cut-off values for discriminating mild, moderate, severe fibrosis and cirrhosis were 6.4, 7.2, 8.5 and 9.9 kPa. Conclusions: ElastPQ is a method that seems to be good for the diagnosis of all stages of liver fibrosis with good diagnostic accuracy. Reference: [1] Tsochatzis et al. Elastography for the diagnosis of severity of fibrosis in chronic liver disease: a meta-analysis of diagnostic accuracy. J Hepatol. 2011 Apr; 54 (4): 650 – 9.