Advances in portal pressure measurement: Endoscopic techniques, challenges, and implications for liver transplantation

Table 2 Non-invasive imaging modalities for assessment of clinically significant portal hypertension

Imaging modality	Description	Sensitivity (%)	Specificity	Limitations
Ultrasound elastography (liver stiffness measurement)	Uses shear wave elastography or transient elastography to assess liver stiffness, which correlates with portal pressure	0.81 (0.73–0.87)	0.83 (0.77–0.88)	May be less accurate in obese patients or those with ascites. Affected by liver inflammation and cholestasis
Spleen stiffness measurement	Measures spleen stiffness to estimate portal pressure and PH severity. Reflects not only increased intrahepatic vascular resistance but also splenic haemodynamic and fibrosis	0.85 (0.69–0.93)	0.86 (0.74–0.93)	A dedicated device is required. Difficult to measure without splenomegaly
Magnetic resonance elastography	Uses MRI technology to assess liver stiffness, capable of covering the whole liver	80-90	90-95	High cost, limited availability
Doppler ultrasound	Measures the velocity of blood flow in the PV and hepatic veins, used to infer PH	70-90	70-90	Operator-dependent, limited by technical factors (e.g., patient positioning)
Computed tomography or MRI-based imaging (with contrast)	Involves imaging of the PV, spleen, and liver, providing visual signs of PH, such as varices or splenomegaly	70-90	75-90	Limited sensitivity in detecting mild PH, expensive

MRI: Magnetic resonance imaging; PH: Portal hypertension; PV: Portal vein.