Instant MRI - Cardiac care in real time
Being strapped into the MRI machine for cardiovascular care can seem like a lifetime to many heart patients.
To help end the claustrophobia, a team of engineers at The Ohio State University is collaborating with their medical colleagues to make the procedure almost instantaneous – and more effective.
Ohio State Department of Electrical and Computer Engineering (ECE) assistant research professor Rizwan Ahmad, PhD student Adam Rich, and ECE professor Lee Potter collaborated with cardiovascular medicine and radiology professor Dr. Orlando Simonetti to develop the new MRI technique. They were assisted by Ohio State adjunct assistant professor and Siemens Healthcare scientist Ning Jin.
Simonetti said the new process the team proposes allows for over 10 times faster patient MRI scans over current methods, creating real-time and non-invasive imaging of a beating heart. Several patent applications are now pending on their methods and at least one Columbus hospital is already looking at implementing the technology.
Along with cardiologist and ECE alumna Dr. Subha Rahman, Simonetti directs Cadiovascular MRI research at the Ohio State Wexner Medical Center, where their work is performed.
“MRI is the only imaging modality capable of 3D measurement of blood flow velocity in all directions. These measurements can be critically important in the evaluation of patients with congenital heart disease or valve disease and can be used to assist in decisions regarding the timing and strategy for surgery,” Simonetti said. “Unfortunately, current MRI methods used to make these measurements can take 10 to 20 minutes, making them clinically impractical and prone to errors caused by patient motion. We hope to use this new technology to reduce the scan time from minutes down to seconds, enabling these scans to fit into the clinical workflow, thereby making important information on blood flow available to physicians.”
For these researchers, reducing the MRI scan time is personal as well. Potter said his daughter is scheduled to receive an MRI soon and Simonetti said he has known MRIs that lasted almost an hour - a time which is not conducive to helping patients become more accepting of the important cardiac procedure.
Magnetic resonance imaging, or MRI, is a medical procedure that uses strong magnetic fields and radio waves, instead of X-rays, to produce cross-sectional images of organs and internal structures in the body. According to the FDA, and numerous health market reports, more than 30 million scans are performed each year.
The collaborative research efforts by the Ohio State team are outlined in the paper, “A Bayesian Model for Highly Accelerated Phase-Contrast MRI,” recently published in the Magnetic Resonance in Medicine Journal.
Providing more detail, Potter said the team proposes a new data processing approach called ReVEAL, or "Reconstructing Velocity Encoded MRI with approximate message passing Algorithms," which uses computer algorithms to create an MRI video from the faint MRI signals gathered by the scanner. Data collected during a few heartbeats is then processed to synthesize a video view of a single representative beat.
“By collecting a more informative set of measurements, and then processing to take into account physical structure in the images, we are able to significantly reduce the scan time,” Potter said.
In other words, being stuck for an extended length of time in the MRI scanner could become a thing of the past.
“Our target is to acquire data sufficient for 3D imaging in about a dozen heart beats,” Potter said.
The radar-imaging strategies the team incorporates, he said, were originally developed through research funding provided by the United States Department of Defense.