Arlington, Texas — Scientists at the University of Texas at Arlington have developed a groundbreaking method to improve the accuracy of heart function tests conducted inside MRI machines, offering new hope for better diagnosis of cardiovascular conditions.
Dr. Michael Nelson, a UTA researcher, had a key realization after seeing a photograph of astronauts in space wearing special garments known as lower body negative-pressure (LBNP) pants. These suits are designed to simulate the effects of gravity on the human body in a weightless environment.
That image sparked a question for Dr. Nelson: Could this same technology help improve the way we test heart function inside an MRI?
A New Approach to MRI Heart Stress Tests
Traditional cardiac stress tests in MRI machines require patients to lie flat. This position allows more blood to flow back to the heart from the lower body due to the absence of gravity. As a result, the heart appears to pump more efficiently than it does under normal conditions, potentially masking symptoms of heart disease.
To address this, Nelson’s team began using LBNP pants to simulate the effects of standing up while patients remain in the MRI machine. The pants apply gentle suction to the lower body, reducing blood return to the heart and revealing a more accurate picture of how it functions under stress.
“This completely changes how we perform exercise cardiac MRI,” said Nelson. “In my view, this should be the new standard. Exercise cardiac MRI without lower body negative-pressure pants isn’t telling the whole story.”
The university holds a pending patent for the method, which positions UTA among a handful of institutions globally exploring this advanced imaging technique.
Noninvasive Oxygen Monitoring: Another Major Step
In addition to the LBNP innovation, Nelson’s team has also made strides in using MRI to assess how the body uses oxygen during exercise—without the need for invasive procedures.
In a recent study published in the American Journal of Physiology, the researchers demonstrated that MRI could accurately measure venous oxygen levels, a key indicator of how well the body extracts oxygen from the blood. Traditionally, this required inserting a catheter into the inferior vena cava, the body’s largest vein.
“This new method eliminates the need for a catheter while maintaining accuracy and reliability,” said Richard Thompson, a professor at the University of Alberta and senior author of the study.
By combining this oxygen data with cardiac output—how much blood the heart pumps per minute—scientists can now calculate how much oxygen the body actually uses during exercise. This measurement is a strong predictor of future illness or even risk of death.
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