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.