Optimal number of valid measurements for the assessment of liver stiffness using 2D-SWE.GE

Background and aim: According to the manufacturer's recommendations, in order to obtain reliable liver stiffness values, 10 valid measurements need to be performed. The aim of this study was to evaluate whether 5 liver stiffness measurements are as useful as 10.

Material and method: 109 consecutive subjects with or without chronic hepatophaties were included in the study, in whom liver stiffness (LS) was evaluated by 2D- Shear Waves Elastography implemented on the LOGIQ E9 system (GE Healthcare, Chalfont St Giles – UK). 10 valid measurements were performed in each case, and the mean, median, standard deviation (SD), and interquartile range (IQR) were calculated. We compared the first 5 measurement group with the 10 measurement group. We used the following 2D-SWE.GE cut-off values: F< 2: 8.3 KPa; F = 4: 12 KPa.

Results: The structure of the cohort study was the following: Group I (F < 2: 43/109 (39.5%), Group II (F2-F3: 27/109 (25%); Group III (F = 4: 39/109 (35.5%). We found no significant statistical differences between the LS measurements in the three groups, neither for median (p = 0.86), mean (p = 0.72), IQR (p = 0.59) or SD (p = 0.41). There was also no significant differences between the LS measurements in the 3 groups of fibrosis F< 2- F2F3- F = 4 (all p > 0.05).

Conclusion: 5 valid measurements may be enough to quantify the liver stiffness by 2D-SWE.GE without significant loss of accuracy even in patients with advanced liver disease.