Research News

02/19/2025

What is diffusion MRI: how advanced cardiac imaging can benefit care, research

Dr. Christopher Nguyen discusses current challenges in heart screening and imaging, and how he’s overcoming them by advancing cardiac MRI.

A false-colored MRI scan of a heart. The image is so high-resolution you can see each individual fiber making up the tissue.

Christopher Nguyen is a recognized leader in advancing cardiac diffusion MRI, a technique that lets you take high-resolution images of the heart

Cardiac MRI is the gold standard for image-based heart screening, but the technology we use to take and analyze pictures of our hearts has not changed in over 40 years. Cleveland Clinic’s Christopher Nguyen, PhD, is looking to change that.

“Interpreting an MRI image is almost like an art. The image itself doesn’t show the exact type and location of heart damage or disease,” says Dr. Nguyen, founder of Cleveland Clinic’s Cardiovascular Innovation Research Center (CIRC). “There’s a major cognitive load involved for cardiac radiologists and referring physicians in interpreting these images to determine the best treatment.”

Dr. Nguyen, who started his lab with dual appointments in in Cleveland Clinic’s Heart, Vascular and Thoracic Institute and Biomedical Engineering in 2022, is regarded as a “founding father” of the cardiac diffusion MRI, a technology being implemented to improve heart imaging and build “digital twins” to further care and research.

What is diffusion MRI?

Regular MRIs capture pictures based on the location of water molecules. Diffusion MRIs take things a step further by capturing the movement of water molecules in our bodies as they diffuse, or travel, through our tissue microstructure. Diffusion MRIs give radiologists detailed images of an organ down to a 100-micrometer scale, letting them easily identify the damage in a tissue.

“Diffusion cardiac MRI can identify early forms of heart failure to ensure patients receive treatment sooner," Dr. Nguyen says. “Diffusion MRI can also potentially detect small amounts of tissue damage before someone exhibits symptoms, making it an attractive method to proactively treat at-risk individuals.”

Dr. Nguyen has been working on cardiac diffusion MRI since graduate school. The Society for Cardiovascular and Magnetic Resonance recently incorporated his expertise into a consensus statement that provides recommendations for clinical and research-based cardiac diffusion MRI, leading to Cleveland Clinic’s recent adoption of the technique.

Another false-colored diffusion MRI of the heart, from a different angle. The image shows the millions of overlapping muscle fibers making up the heart at a very high resolution.

The heart may look smooth from the outside, but the deeper layers of our heart are made up of millions of individual muscle fibers. Diffusion cardiac MRI lets radiologists and perscribing physicians see these fibers at unprecedented resolutions.

How can advances in diffusion MRI help combat cardiac metabolic disease?

In addition to diffusion MRI, Dr. Nguyen is also perfecting an imaging method to show how microstructures in the heart metabolize energy.

“Knowing what type of damage is in the heart, and where it is, is helpful. But what would be even more helpful is knowing what's causing that damage in the first place," he says. “A more complete picture will help radiologists and physicians can quickly and easily tailor treatment regimens to a patient's specific needs."

His proof-of-concept study demonstrated the technique’s potential use by measuring how bariatric surgery impacts an individual’s cardiovascular metabolism.

When Dr. Nguyen started making plans to move his diffusion cardiac MRI technology into the clinic, he learned that only four of Cleveland Clinic’s 80 MRI locations would be able to provide the service.

“The issue isn't that our other 76 machines can’t do it; it's that radiologists who know how to do cardiac scans are extremely rare,” Dr. Nguyen says. “I realized that I could still improve the field of cardiac imaging while my technology was in development just by expanding access to the current techniques we already have.”

A green 3D rendering of a heart. The outer and inner layers are visible.

This cardiac digital twin is a virtual clone of a human heart, made from hundreds of pictures taken of a real patient receiving cardiac MRI. Physicians can use this digital twin to model interventions, design tailor-made shunts and other devices, simulate surgeries and more to determine the best method to treat the patient

How can machine learning help us make cardiac digital twins?

Dr. Nguyen and his team developed a software program called AutoCMR that lets standard MRI machines automatically take hundreds of images at a time to guarantee they get the right shot. Then using machine learning, the program identifies which of the hundreds of images will show the damaged area.

“AutoCMR democratizes cardiac MRI by letting any radiologist capture and analyze high-quality heart images with the push of a button,” he says.

Because AutoCMR takes so many pictures of the heart, radiologists can essentially download an individual patient's entire heart data in a single MRI appointment. Dr. Nguyen’s current research is using this data to make a digital twin – a data model that can simulate how different treatments and devices would work in individual patients.

“We can run simulations on these downloaded hearts to forecast disease, print out tailor-made cardiovascular devices and valves, and more. All from a less than 30-minute scan,” he says. “This is the kind of thing that used to just be science fiction. It’s so exciting to help bring it into reality to help people combat and prevent heart disease.”