Fig 1.
Method of selection of healthy subjects.
Flow chart of data collection.
Table 1.
The characteristics of healthy subjects, by age group.
Fig 2.
Samsung RS80A SWE performed on a healthy liver.
The figure illustrates Samsung RS80A SWE method performed on a healthy subject. The yellow box (centre) represents the shear-wave measurement area and is expressed below the obtained elasticity measurement of 3.4 kPa.
Fig 3.
2D-SWE by GE S8 performed on a healthy liver.
The figure illustrates the method of 2D-SWE by GE performed on a healthy subject. The coloured box (centre) represents the elastogram, and the circle represents the ROI where the elastic modulus (LSM, liver stiffness measurement) of the liver is acquired. The blue colour indicates soft liver tissue, as semi-quantitatively presented by the colour scale to the left.
Table 2.
Liver stiffness values (kPa) for the different methods.
Fig 4.
Liver stiffness (kPa) in a healthy cohort for the different methods.
This boxplot figure displays the median and the interquartile range for LSM for each system. Whiskers represent the 90% percentile of the measured liver stiffness. The height of the box represents the variability in LSM between the healthy study subjects for each of the following three systems: blue, GE S8 2D-SWE; green, Transient Elastography (TE, Fibroscan) and orange, Samsung RS80A SWE. P-values indicate if there is a significant difference between the novel systems (Samsung RS80A or GE S8) and TE.
Fig 5.
Liver stiffness (kPa) of healthy adult livers, interobservation.
The boxplot shows interobservation between observer A (dark blue) and B (light blue). The horizontal axis represents the systems Samsung RS80A SWE and GE S8 2D-SWE and the p-value is given. For boxplot interpretation, we refer to Fig 4.
Fig 6.
Correlation between observer A and B. The horizontal and vertical axes represent measurements by observer B and A, respectively. The unit measured is kilopascals (kPa). The line in the graph represents the line of unity. The Pearson correlation coefficient (r) and significance (p) for each system is given in the lower right corner. For colour representation, we refer to Fig 4.
Fig 7.
Limits of agreement for Samsung RS80A SWE.
The figure presents the limits of agreement for Samsung RS80A. The horizontal axis represents the common mean value of all measurements in both observers for, while the vertical axis represents the difference between individual measurements and this common mean (kPa), displaying the variability of measurements. The black line within each system represents the common mean value, the dotted lines represent the 95% confidence intervals. A mean value close to 0 on the vertical axis means that the two observers apply the measurement scale without bias.
Fig 8.
Limits of agreement for 2D-SWE GE S8.
Limits of agreement for 2D-SWE GE S8, for legend we refer to Fig 7.
Fig 9.
Liver stiffness (kPa) of healthy adult livers, by gender.
The boxplot shows the liver stiffness by gender. The horizontal axis represents the gender; males and females. The colour interpretation for each system and the level of significance is given in the upper right corner. For legend interpretation, we refer to Fig 4.
Table 3.
Liver stiffness values (kPa) of healthy adult livers, by gender.
Table 4.
Liver stiffness values (kPa) of healthy adult livers, by age group.
Fig 10.
Liver stiffness (kPa) of healthy adult livers, by weight group.
The boxplot shows the liver stiffness by weight group. The horizontal axis represents the BMI group. The colour interpretation for each system and the level of significance is given in the upper right corner. For boxplot interpretation, we refer to Fig 4.
Fig 11.
Difference in liver stiffness (kPa) for 5 and 10 measurements.
The boxplots show difference in liver stiffness for 5 and 10 measurements. The horizontal axis represents the systems, and the vertical axis the liver stiffness measured. The colour interpretation for 5 and 10 measurements (green and blue, respectively) is given in the upper right corner. For boxplot interpretation, we refer to Fig 4.