A new technique for conducting cardiac magnetic resonance imaging (MRI) tests improves patient comfort, shortens testing time and has the potential to increase diagnostic accuracy and reliability.
The MR multitasking approach solves the problem many cardiologists face when using conventional methods to perform MRI scans: how to get a still image when a beating heart and blood flow can blur the picture.
The current protocol is to ask patients undergoing cardiac MRI to hold their breath while images are being taken — but then each image must be timed precisely to a specific part of a heartbeat. This method has proved difficult, unreliable and unsuitable for patients, especially those who have irregular heartbeats or breathing problems.
Rather than trying to avoid the motion caused by breathing and heartbeats, the researchers from Cedars-Sinai in Los Angeles decided to embrace the movement by incorporating motion and time into the analysis. MR multitasking continuously acquires image data and then, when the test is completed, the program separates out the overlapping sources of motion and other changes into multiple time dimensions.
MR multitasking was demonstrated to be accurate when tested in 10 healthy volunteers and 10 cardiac patients. It was also more comfortable for patients because they were no longer required to hold their breaths, and the team was able to complete three cardiac MRI tests in as little as 90 seconds. Current standard approaches would have taken many times as long.
The images have six dimensions, and the researchers explain that if a picture is 2D, then a video is 3D because it adds the passage of time. The videos are 6D because clinicians can play them back four different ways, including cardiac motion, respiratory motion and two different tissue processes that reveal cardiac health.
MR multitasking is undergoing initial clinical investigation at several medical centers in the U.S. and the team now is looking to expand MR multitasking to patients with other diseases, like cancer.
The research is published in Nature Biomedical Engineering.