Subharmonic Aided Pressure Estimation of Portal Hypertension
Thursday, July 28, 2016
3:00 PM-5:00 PM
BIOMED PhD Research Proposal
Title:
Subharmonic Aided Pressure Estimation of Portal Hypertension
Speaker:
Ipshita Gupta, PhD Candidate, School of Biomedical Engineering, Science and Health Systems
Advisors:
Peter Lewin, PhD, Richard B. Beard Distinguished University Professor, School of Biomedical Engineering, Science and Health Systems
Flemming Forsberg, PhD, Professor of Radiology, Thomas Jefferson University
Abstract:
Portal hypertension is difficult to diagnose at its early stage as symptoms rarely manifest until the later stages of liver disease. As pressures in the portal vein cannot be directly measured, portal pressures are estimated using the hepatic venous pressure gradient (HVPG). This is defined as the difference between the wedged and free hepatic venous pressures. Patients with an HVPG greater than 10 mmHg are at increased risk of developing varices, while patients with an HVPG above 12 mmHg are at risk of variceal bleeding (which is associated with mortality rates of 15-20 %). The current clinical technique for measuring HVPG is invasive and requires insertion of a balloon catheter via a transjugular approach into the hepatic vasculature.
Noninvasive techniques such as ultrasound, magnetic resonance imaging (MRI) and computed tomography (CT) have a very poor sensitivity to portal pressure estimation and are therefore, not accurate enough to be used routinely for diagnosis of portal hypertension. Thus, an alternative accurate, noninvasive ultrasound based procedure would be a major development in the diagnosis of portal hypertension making the diagnosis safer, quicker and relatively cheaper. Hence, the fundamental hypothesis of this project is that portal vein pressures can be monitored and quantified noninvasively in humans using contrast-enhanced subharmonic-aided pressure estimation (SHAPE).
SHAPE is based on the inverse relationship between the subharmonic amplitude of contrast microbubbles (obtained by transmitting at the fundamental frequency fo and receiving at fo/2) and the ambient pressure. The hypothesis of this study is that portal vein pressures can be monitored and quantified noninvasively in humans using SHAPE.
Contact Information
Ken Barbee
215-895-1335
barbee@drexel.edu