Expanding the reach of cardiac MRI

At the forefront of cardiac imaging, a talented group of physicians and researchers at The Ohio State University Wexner Medical Center is on a mission to translate lowfield magnetic resonance imaging technology into high impact for the patients they treat. With the recent installation of a new 0.55T (tesla) MRI machine, they are quickly advancing that mission for the benefit of more than 2,000 patients every year.

OS: While cardiac MRI can’t fully replace other forms of cardiac imaging, it is considered the gold standard for analyzing blood flow, heart function and heart tissue. Cardiac ultrasound, or echocardiography, is significantly more portable and accessible than cardiac MRI, but MRI produces 3D images that can provide substantially more information. Computerized tomography (CT) scans can produce better-quality images of the coronary arteries and blood vessels, but cardiac MRI offers more detailed images of the structure and function of the heart muscle.

OS: Early MRI scanners operated at low field, but over time MRI technology has evolved toward a “bigger is better” mentality that emphasizes the development of higher and higher field MRI machines, even as high as 11T. This evolution makes sense; higher field means more signal, more detail and faster scanning. But there are also plenty of downsides to high-field MRI. These machines are heavier and more expensive than their low-field counterparts, and their openings are narrower. High-field MRI also holds less promise for patients with implanted devices because of the way metal distorts MR images. My colleagues and I investigated the potential for low-field MRI several years ago and found that we could produce clearer images at a lower field, and this could potentially make MRI technology useful for a wider patient population. We collaborate closely with Siemens Healthineers. The company shared our vision and released the 0.55T MAGNETOM Free.Max in late 2021.

OS: Compared to its higher-field counterparts, the 0.55T weighs significantly less and is much less costly to install and operate. Its larger opening — 80 centimeters compared with the standard 60-70 centimeters — also expands access for patients who are severely obese or claustrophobic. Unlike higher field machines, which struggle to evaluate lung structure and function because of the air in the lungs, the 0.55T has the potential to provide clear images of the lungs. Perhaps most significantly, this new technology enables the development of MRI-guided heart catheterization, which is challenging to perform using higher-field machines that tend to heat up the wires used during such procedures. Finally, we hope to make the 0.55T machine the technology of choice for patients with implanted devices, as the metal in these devices causes less distortion with low-field MRI.

OS: No. Just like with different forms of cardiac imaging, each MRI field strength offers its own distinct advantages. The Ohio State University Heart and Vascular Center has the only imaging program in the world with these three different magnet strengths — 0.55T, 1.5T and 3T — dedicated to cardiovascular imaging. This gives us the unique opportunity to put the right patient in the right machine to get the best outcome. Together with its higher field counterparts, the 0.55T MRI will go a long way toward expanding access to leading-edge cardiac care for patients in central Ohio and beyond.

To learn more visit health.osu.edu