Gravity assistance enables liver stiffness measurements to detect liver fibrosis under congestive circumstances

Figure 2 Alteration of the inferior vena cava diameter and liver stiffness after changing body positions. A: The inferior vena cava diameter was significantly reduced in patients with normal two-dimensional shear wave elastography (2dSWE) values in the supine position (Normal, P = 0.013, 13.1 ± 3.7 vs 12.4 ± 3.5 mm) or patients with abnormal 2dSWE in the supine position that further hardened in the left decubitus position (Harden, P = 0.0070, 13.9 ± 3.6 vs 13.1 ± 3.4 mm). However, the diameter was not reduced in patients with abnormal 2dSWE in the supine position that softened in the left decubitus position (Soften, P = 0.32, 13.3 ± 3.5 vs 13.0 ± 3.5 mm). The horizontal bars in each plot indicate the average (“Bold”) and standard deviation. Supine and LtD indicate the supine and left decubitus positions, respectively; B: 2dSWE in the supine position revealed a significant positive correlation with the difference in 2dSWE between the two body positions only in the Soften group (red) (P < 0.0001, r = 0.38) but not in the Normal (green) and Harden (blue) groups; C: In the Soften group, 2dSWE values in the supine position were plotted against the difference in 2dSWE between the supine and left decubitus positions in the right or left lobe. A Spearman's correlation coefficient of 0.48 in the right lobe was higher than 0.31 in the left lobe. The black continuous and dotted lines reveal the best hit and 95% confidence band in the equation of least squares between 2dSWE values in the supine position and the difference in 2dSWE for two body positions in B and C. IVC: Inferior vena cava; Sp: Supine; 2dSWE: Two-dimensional shear wave elastography.