Applicability and variability of liver stiffness measurements according to probe position

AIM: To investigate the liver stiffness measurement (LSM) applicability and variability with reference to three probe positions according to the region of liver biopsy. METHODS: The applicability for LSM was defined as at least 10 valid measurements with a success rate greater than 60% and an interquartile range/median LSM < 30%. The LSM variability compared the inter-position concordance and the concordance with FibroTest. RESULTS: Four hundred and forty two consecutive patients were included. The applicability of the anterior position (81%) was significantly higher than that of the reference (69%) and lower positions (68%), (both P = 0.0001). There was a significant difference (0.5 kPa, 95% CI 0.13-0.89; P < 0.0001) between mean LSM estimated at the reference position (9.3 kPa) vs the anterior position (8.8 kPa). Discordance between positions was associated with thoracic fold (P = 0.008). The discordance rate between the reference position result and FibroTest was higher when the 7.1 kPa cutoff was used to define advanced fibrosis instead of 8.8 kPa (33.6% vs 23.5%, P = 0.03). CONCLUSION: The anterior position of the probe should be the first choice for LSM using Fibroscan, as it has a higher applicability without higher variability compared to the usual liver biopsy position. (C) 2009 The WJG Press and Baishideng. All rights reserved.