Ultrasound With Subharmonic Imaging and Subharmonic Aided Pressure Estimation (SHAPE) to Identify Portal Hypertension

This clinical trial tests the how well an ultrasound with subharmonic imaging and the subharmonic aided pressure estimation (SHAPE) technique works in identifying portal hypertension (PH). An ultrasound takes pictures of the inside of the body by bouncing sound waves off organs. PH is high blood pressure in the vein that carries blood to the liver from the stomach, small and large intestines, spleen, pancreas, and gallbladder. The complications associated with PH are clear only after severe liver dysfunction or liver cirrhosis develops and are accompanied by relatively high mortality rates (20-70% mortality within 2 years). Thus, identifying PH earlier is beneficial. The hepatic venous pressure gradient (HVPG) obtained using an invasive catheterization procedure remains the standard for assessing PH. However, using this invasive procedure to assess PH prevents frequent pressure monitoring. Thus, a noninvasive technique to estimate PH is beneficial not only for diagnosis but also for monitoring treatment and disease progression. The SHAPE technique is a noninvasive ultrasound-based imaging technique that can estimate pressure with an ultrasound contrast agent. A noninvasive technique using an ultrasound with subharmonic imaging and the SHAPE technique may work in identifying PH.

Inclusion Criteria: * Provide signed and dated informed consent form * Willing to comply with all study procedures * Adult patients (age of 18 years or older) * If a female of child-bearing potential, must have a negative pregnancy test * Be scheduled for HVPG measurement Exclusion Criteria: * Patients who are unable to provide consent * Females who are pregnant or nursing * Patients with known or suspected hypersensitivity to perflutren lipid microsphere or its components, such as polyethylene glycol (PEG)