Quality criteria for the measurement of liver stiffness

Liver elastography offers the possibility of a quick, non-invasive, and painless evaluation of the liver with immediate results at bedside. Transient elastography is the most validated technology, and many others such as point shear wave elastography, 2D-shear wave elastography, or magnetic resonance elastography have been developed. To ensure the best evaluation, several conditions of examination must be respected for liver stiffness measurement. Indeed, patient, operator and examination characteristics have all been shown to influence the result of liver stiffness measurement. Food intake increases liver stiffness, whereas withdrawal in alcoholics is associated with a decrease in elastography results. Inter-observer reproducibility of the measurement seems suboptimal, and the influence of the operator experience is still being debated. The measurement site and the FibroScan® probe must be correctly chosen. Finally, the intrinsic characteristics and quality criteria of the measurement, especially the interquartile range/median ratio, must be carefully checked to avoid overestimation of liver stiffness. Most of the results come from studies which have evaluated transient elastography, with less data available for the other technologies. Liver stiffness measurement could appear as a simple way to explore the liver, but several conditions must be met before deciding the patient management according to its result.