Endogenous motion of liver correlates to the severity of portal hypertension

Table 1 Investigated endogenous motion parameters

No.	Parameter	Description
1	dantero	Maximal amplitude of endogenous displacements towards the probe, μm
2	dretro	Maximal amplitude of the displacements backward, μm
3	dRMS	Average level of motion, μm
4	µROI[0…10 Hz, 2 cm × 2 cm]	Average strain [estimated for the 0…10 Hz sub-band of endogenous motion in the 2 cm × 2 cm ROI], μm/cm
5	σROI[0…10 Hz, 2 cm × 2 cm]	Standard deviation of strain [0…10 Hz, 2 cm × 2 cm], μm/cm
6	µROI[0…10 Hz, 1 cm × 1 cm]	Average strain [0…10 Hz, 1 cm × 1 cm], μm/cm
7	σROI[0…10 Hz, 1 cm × 1 cm]	Standard deviation of strain [0…10 Hz, 1 cm × 1 cm], μm/cm
8	µROI[10…20 Hz, 2 cm × 2 cm]	Average strain [10…20 Hz, 2 cm × 2 cm], μm/cm
9	σROI[10…20 Hz, 2 cm × 2 cm]	Standard deviation of strain [10…20 Hz, 2 cm × 2 cm], μm/cm
10	µROI[10…20 Hz, 1 cm × 1 cm]	Average strain [10…20 Hz, 1 cm × 1 cm], μm/cm
11	σROI[10…20 Hz, 1 cm × 1 cm]	Standard deviation of strain [10…20 Hz, 1 cm × 1 cm], μm/cm

ROI: Region of interest; RMS: Root mean square.

Table 2 Demographic and clinical data of the patients

Variable	Characteristics (n = 36)
Sex (male/female; %)	58.3/41.7
Age (yr; SD)	54.25 (8.82)
Aethiology (% of patients)
Alcohol cirrhosis	36.1
HCV cirrhosis	63.9
Child-Pugh score (A/B/C; % of patients)	58.3/36.2/5.6
HVPG (mmHg; SD)	14.3 (5.9)
HVPG 1-5 mmHg (% of patients)	2.8
HVPG 6-9 mmHg (% of patients)	25
CSPH; HVPG ≥ 10 mmHg (% of patients)	72.2
SPH; HVPG ≥ 12 mmHg (% of patients)	69.4

HCV: Hepatitis C virus; HVPG: Hepatic venous pressure gradient; CSPH: Clinically significant portal hypertension; SPH: Severe portal hypertension.

Table 3 Correlations between the investigated parameters and hepatic venous pressure gradient

No.	Parameter	Spearman’s ρ	P value
1	dantero	-0.31	0.07
2	dretro	0.34	0.04
3	dRMS	-0.33	0.05
4	µROI[0…10 Hz, 2 × 2 cm]	-0.38	0.04
5	σROI[0…10 Hz, 2 cm × 2 cm]	-0.42	0.01
6	µROI[0…10 Hz, 1 cm × 1 cm]	-0.38	0.02
7	σROI[0…10 Hz, 1 cm × 1 cm]	-0.27	0.11
8	µROI[10…20 Hz, 2 cm × 2 cm]	-0.19	0.28
9	σROI[10…20 Hz, 2 cm × 2 cm]	-0.14	0.43
10	µROI[10…20 Hz, 1 cm × 1 cm]	-0.16	0.34
11	σROI[10…20 Hz, 1 cm × 1 cm]	-0.16	0.36

ROI: Region of interest; RMS: Root mean square.

Table 4 Diagnostic performance of parameters for the diagnosis of portal hypertension

Parameter	Value	Sensitivity	Specificity	PPV	NPV	P value
dretro
CSPH	132.34 µm	100	80	93	100	0.0001
SPH		100	72	89	100	0.0001
σROI[0…10 Hz, 2 cm × 2 cm]
CSPH	1.28 µm/cm	73	70	86	50	0.036
µROI[0…10 Hz, 1 cm × 1 cm]
CSPH	3.92 µm/cm	73	80	90	53	0.0024

CSPH: Clinically significant portal hypertension; SPH: Severe portal hypertension; PPV: Positive predictive value; NPV: Negative predictive value; ROI: Region of interest.