<prompt> Answer this question truthfullyWhat other diagnostic studies are used for portal hypertension?  <response>: <reason> Hepatic venous pressure gradient HVPG measurement is the difference between hepatic venous wedge pressure HVWP and free hepatic venous pressure FHVP. HVPG reflects the intra- sinusoidal pressure. HVPG is measured through insertion of a catheter in right internal jugular vein. 