Liver pressure monitoring using ultrasound microbubbles: Study
Repeated damage to the liver can cause scar tissue to gradually accumulate inside the organ. This condition, called cirrhosis, alters the liver's normal structure and can restrict blood flow through the portal vein, which carries blood from the digestive organs to the liver. This condition is called portal hypertension (PH), one of the most serious complications of advanced liver disease. Portal hypertension can cause serious complications such as bleeding from enlarged veins in the esophagus and stomach, fluid buildup in the abdomen called ascites, and kidney failure known as hepatorenal syndrome.
The current method used to detect portal hypertension is called hepatic venous pressure gradient, or HVPG. In this procedure, doctors insert a catheter through a vein in the neck or groin and guide it into the liver circulation to measure blood pressure linked to portal hypertension. HVPG can also help doctors assess the severity of cirrhosis and the risk of complications. However, it is invasive, expensive, and requires specialized medical equipment and trained experts to perform.
A study published in the journal Portal Hypertension & Cirrhosis on April 13, 2026, explores the use of contrast-enhanced ultrasonography (CEUS) as a safer and less invasive alternative for assessing portal hypertension in patients with cirrhosis. The study was led by Dr. Wenjuan Wang and Dr. Guo Zhang from the Department of Gastroenterology, Guangxi Hospital Division of The First Affiliated Hospital, Sun Yat-sen University, China.
Dr. Wang explains the limitations of HVPG, “First, the method is invasive, making it hard for patients to accept in early-stage PH. Second, it requires specially trained interventionalists, which introduces technical risk and inconsistent detection levels. Third, it relies on expensive catheter consumables and large-scale medical equipment.”
CEUS is a noninvasive imaging technique where microbubble-based ultrasound contrast agents are injected into the bloodstream during an ultrasound scan. These microbubbles respond strongly to ultrasound waves, allowing doctors to observe how blood flows through the liver and surrounding blood vessels. Importantly, these microbubble-based contrast agents are not nephrotoxic and are associated with fewer severe allergic reactions compared to iodinated contrast agents.
The paper discusses various CEUS parameter measurements linked to portal hypertension, including hepatic vein arrival time (HVAT) and intrahepatic transit time (ITT). These measurements track how quickly the microbubble contrast agents move through the liver circulation and can help doctors estimate the severity of portal hypertension. Some studies also found that these measurements may help identify patients at high risk of dangerous bleeding from enlarged veins.
One important technique discussed in the study is called subharmonic aided pressure estimation, or SHAPE. This method measures changes in the sound signals produced by the microbubbles to estimate pressure in the portal circulation. Several clinical studies reviewed in the paper found that SHAPE measurements closely matched HVPG measurements, suggesting that CEUS could become a reliable noninvasive tool for diagnosing portal hypertension.
In one large clinical study involving 125 patients, SHAPE measurements showed high accuracy in identifying patients at increased risk of variceal bleeding, one of the leading causes of death in people with cirrhosis. The researchers also found that CEUS may help monitor patients who undergo transjugular intrahepatic portosystemic shunt (TIPS) procedures, which are used to redirect blood flow and reduce pressure in the portal vein.
According to the researchers, CEUS shows strong potential as a noninvasive tool for diagnosing portal hypertension, though certain technical and clinical limitations remain. “Contrast-enhanced ultrasonography has high diagnostic accuracy for clinically significant portal hypertension and severe portal hypertension, and its parameters can help guide treatment decisions. However, there is no standardized method for directly measuring portal pressure from ultrasound images, and the results can depend on operator experience and image quality,” says Dr. Zhang.
Cirrhosis is becoming a growing global health concern. Rising alcohol consumption and the increasing prevalence of fatty liver disease associated with obesity and changing dietary habits are driving an increase in chronic liver disease worldwide. Noninvasive and accessible methods such as contrast-enhanced ultrasonography could significantly improve the diagnosis, monitoring, and management of the disease, helping to prevent its progression.
Reference:
D.Huang, Z.Liu, L.Liu, F.Huang, W.Wang, and G.Zhang, “Microbubble-Based Ultrasound Contrast Agents in Contrast-Enhanced Ultrasonography for Managing Portal Hypertension in Cirrhosis,” Portal Hypertension & Cirrhosis0 (2026): e70040, https://doi.org/10.1002/poh2.70040.
