Microbubble‐Based Ultrasound Contrast Agents in Contrast‐Enhanced Ultrasonography for Managing Portal Hypertension in Cirrhosis

ABSTRACT Contrast‐enhanced ultrasonography (CEUS), enabled by microbubble‐based agents, provides a noninvasive alternative to the hepatic venous pressure gradient (HVPG) for assessing portal hypertension (PH) in cirrhosis. The HVPG is considered the “gold standard” for assessing portal vein pressure (PVP); however, its clinical application is limited by its invasive nature, high cost, and varying levels of detection technology. Therefore, there is a critical unmet need to develop a safe, reliable, convenient, and accessible noninvasive diagnostic method or means to diagnose and dynamically and accurately monitor PVP. Recently, with the rapid progress in digital technology and imaging modalities and the accessibility of microbubble‐based ultrasound contrast agents (UCAs), CEUS has shown great promise in the noninvasive assessment of PVP. Microbubble‐based UCAs not only perform well in the diagnosis and dynamic monitoring of PH but also have clinical significance in cirrhosis complications, monitoring the progression of PH, and identifying patients who respond to PH therapy. In this study, we summarize the principles, methods, diagnostic efficacy, and limitations of using microbubble‐based UCAs in CEUS for assessing PVP in patients with cirrhosis.