Endogenous motion of liver correlates to the severity of portal hypertension

Formula 1 

Figure 1 Example illustrating assessment of the endogenous liver displacements and strain. A: region averaged tissue displacement signal obtained in the subsector at time interval (2…3.8) s (three parameters of region averaged displacement signal d_RMS, d_antero and d_retro were evaluated in this study); B: the obtained strain map [amplitude coded in (μm/cm)] together with regions of interest (red rectangle, size 1 cm × 1 cm) used for the local assessment of endogenous strain. ROI: Regions of interest.

Formula 2 

Figure 2 The boxplots and P values representing the derived parameters of endogenous displacements and strain in patients with and without clinically significant portal hypertension (≥ 10 mmHg). A: d_retro; B: µ_{ROI[0…10Hz, 2 cm × 2 cm]}; C: σ_{ROI[0…10Hz, 2 cm × 2 cm]}; D: µ_{ROI[0…10Hz, 1 cm × 1 cm]}. HVPG: Hepatic venous pressure gradient.

Figure 3 The boxplots and P values representing the derived parameters of endogenous displacements and strain in patients with and without severe portal hypertension (≥ 12 mmHg). A: d_retro; B: µ_{ROI[0…10Hz, 2 cm × 2 cm]}; C: σ_{ROI[0…10Hz, 2 cm × 2 cm]}; D: µ_{ROI[0…10Hz, 1 cm × 1 cm]}. HVPG: Hepatic venous pressure gradient.

Figure 4 Receiver operating characteristic curves of d_retro parameter for the diagnosis of portal hypertension. A: Receiver operating characteristic (ROC) curve for clinically significant portal hypertension [hepatic venous pressure gradient (HVPG) ≥ 10 mmHg]; B: ROC curve for severe portal hypertension (HVPG ≥ 12 mmHg).

Figure 5 Receiver operating characteristic curves of σ_{ROI[0–10Hz, 2 cm × 2 cm]} and µ_{ROI[0–10Hz, 1 cm × 1 cm]} parameters for the diagnosis of clinically significant portal hypertension (hepatic venous pressure gradient ≥ 10 mmHg).