Research and Clinical Medicine (Dec 2016)
Which are the best cut-off values for predicting different stages of liver fibrosis for 2d-swe.ge in daily practice?
Abstract
OBJECTIVES AND BACKGROUND To evaluate the performance of 2D share wave elastography from General Electric (2D-SWE.GE) for the noninvasive assessment of liver fibrosis and to identify liver stiffness (LS) cut-off values for predicting different stages of fibrosis, using Transient Elastography (TE) as the reference method. MATERIALS AND METHODS The study group included 331 consecutive subjects with or without chronic hepatopathies in whom liver stiffness (LS) was evaluated in the same session by means of 2 elastographic techniques: TE (FibroScan, EchoSens, Paris, France, M or XL probes) and 2D-SWE.GE (LOGIQ E9, GE Healthcare, Chalfont St Giles, United Kingdom, C1-6-D convex probe). Reliable LS measurements were defined as follows: for TE – the median value of 10 measurements with a success rate of ≥60% and an interquartile range <30% and for 2DSWE.GE - the median value of 10 measurements acquired in a homogenous area and an interquartile range (IQR) <30%. To discriminate between various stages of fibrosis using TE we applied the following cut-offs: F2 - 7 kPa; F3 - 9.5 kPa and F4 - 12 kPa (1). RESULTS Reliable LS measurements were obtained in 317/331 (95.8%) subjects by 2D-SWE.GE, and in 312/331 (94.2%) by TE (p=0.44). The final analysis was performed on 303 subjects with valid measurements using both methods. Based on TE cut-off values we divided our cohort into the following groups: F<2: 30.1%; F=2: 10.2%; F=3: 12.2%; F=4: 47.5%. We found a strong correlation between the obtained LS values following the application of the 2 methods: r=0.83, p<0.0001. Overall, LS values obtained by means of 2D-SWE.GE were significantly lower than those obtained by TE: 10.14±4.24 kPa vs. 16.72±13.4 (p<0.0001). The best cut-off value for F≥2 was 6.7 kPa, for F≥3 it was 8.2 kPa and for F=4 it was 9.3 kPa. CONCLUSIONS The best 2D-SWE.GE cut-off values for predicting F≥2, F≥3 and F=4 were 6.7, 8.2 and 9.3 kPa. REFERENCES 1.Tsochatzis EA, Gurusamy KS, Ntaoula S, Cholongitas E, Davidson BR, Burroughs AK. Elastography for the diagnosis of severity of fibrosis in chronic liver disease: a meta-analysis of diagnostic accuracy. J Hepatol. 2011;54:650-659.
