HMN 2025: How MRI and NASA-inspired pants enhance stress exams and reveal hidden coronary heart points

University of Texas at Arlington researcher Michael Nelson would not recall the specifics of the presentation, however he remembers the picture. It confirmed astronauts floating in area, carrying uncommon gear known as decrease physique negative-pressure pants, which simulate gravity’s pull on the human physique.

The picture sparked an “aha” brief time period for Dr. Nelson: What if the identical idea might be used to enhance coronary heart testing in an MRI?

During an train stress check inside an MRI machine, sufferers usually lie flat. That place causes extra blood to return to the guts from the decrease physique, since gravity is not pulling it downward. This will increase stroke quantity—the quantity of blood the guts pumps with every beat—which may make the guts seem to perform extra successfully, even in individuals with coronary heart illness.

As a outcome, it turns into more durable for docs to detect actual variations in coronary heart efficiency between wholesome and unhealthy sufferers.

Nelson and his workforce use the negative-pressure pants to resolve that drawback. By mimicking the results of standing up, the pants reveal how the guts actually features beneath stress. This patent-pending expertise marks a serious development in coronary heart imaging, and UT Arlington is certainly one of only a few locations on the earth exploring it.

“We’ve utterly reworked the way in which we take a look at train cardiac MRI,” Nelson stated. “In my opinion, the current developments we have made ought to grow to be the brand new commonplace. You should not be doing train cardiac MRI with out decrease physique negative-pressure pants.”

The decrease physique negative-pressure pants are simply certainly one of a number of improvements Nelson and his workforce are creating to advance exercise-based MRI testing. In a current study published within the American Journal of Physiology-Heart and Circulatory Physiology, the researchers confirmed that MRI can be utilized to measure venous oxygen ranges—vital indicators of how effectively the physique is extracting oxygen from the blood—with out inserting an invasive catheter.

Previously, docs needed to insert a catheter into the inferior vena cava, the physique’s largest vein, to get this sort of information. The new MRI approach avoids that invasive step—decreasing threat for sufferers whereas nonetheless offering the identical degree of accuracy and reliability, stated Richard Thompson, a professor on the University of Alberta and senior writer of the review.

Why does that matter? By combining this venous oxygen information with cardiac output—how a lot blood the guts pumps per minute—Nelson’s workforce can now calculate how a lot oxygen an individual’s physique is definitely utilizing throughout train—a big measure that can be utilized to foretell the chance of future sickness or threat of dying.

Taken collectively, these developments present the muse for a brand new technology of coronary heart testing that is utterly noninvasive, extremely repeatable and powered completely by MRI. In bygone days, researchers needed to depend on sufferers utilizing a stationary bike whereas carrying an oxygen masks connected to a metabolic cart and separate scans to picture and consider the guts.

“Our preliminary proof-of-concept information clearly highlights the energy and promise of this strategy,” stated Brandon Hathorn, a Ph.D. scholar in Nelson’s Applied Physiology and Advanced Imaging Laboratory and lead writer of a recently published article on the subject within the European Heart Journal – Cardiovascular Imaging.

The negative-pressure pants, mixed with the brand new noninvasive blood oxygenation technique, symbolize groundbreaking developments in advancing MRI exercise-based coronary heart testing. In November 2024, UTA opened its $6.2 million Clinical Imaging Research Center (CIRC), which encompasses a 3-Tesla MRI machine with a 70-centimeter bore that gives sufficient area for train research.

“What’s nice about MRI is that it is utterly protected—we might do certainly one of these MRI stress exams each day, or each month,” stated Mark Haykowsky, a former UTA professor who’s now on the University of Alberta and is a senior investigator on the mission. “We’ve eradicated quite a lot of the dangers because it’s noninvasive and there is not any ionizing radiation.”

Ultimately, the analysis is important to understanding why some individuals battle with bodily exercise. Poor train capability shouldn’t be solely a predictor of illness and dying—it additionally impacts day by day life, Nelson stated, making even primary duties like strolling to the mailbox or vacuuming really feel tough. By figuring out the precise causes of train intolerance, docs can develop extra focused therapies to assist enhance it.

“Imagine feeling such as you’re working at your absolute most a lot of the day?” Nelson stated. “Being in a position to noninvasively determine particular mechanisms limiting somebody’s capability, whether or not it’s the coronary heart, the muscle groups, or each, will permit for focused remedies to enhance high quality of life and longevity.”