Newswatch: February 2005

Siemens receives patent for new cardiac MRI

They've gone and done it. Siemens Medical Solutions (Malvern, Pa) has developed cardiac MR (CMR) self-gating technology* that is designed to eliminate the need to obtain an electrocardiogram (ECG) signal during imaging. Developed with partners from Northwestern University (Evanston, Ill) and the Cleveland Clinic Foundation, self-gating could potentially ease performance of CMR exams.

"ECG requires lengthy setup times and is not 100 percent effective, due to the distortions of the signal caused by the MRI scanner's magnetic field," said Andrew C. Larson, PhD, assistant professor of radiology at Northwestern University. "The advent of self-gating will make it possible to acquire images of a beating heart without the need of an ECG signal."

One of the biggest challenges in CMR imaging has always been accurate and reliable synchronization of an MRI scan with the heartbeat. The new software is designed to overcome this challenge by extracting cardiac motion information from MRI data, eliminating the need for wires and electrodes to be attached to the patient and avoiding the difficulties of obtaining a reliable ECG signal inside the MRI's high magnetic field.

Techniques do exist that allow CMR exams to be acquired in a real-time mode without ECG synchronization. However, for high resolution and diagnostic value, most CMR exams are acquired over a series of approximately 6–12 successive heartbeats, so accurate synchronization of the scan with the heartbeat is essential.

* Siemens notes that the information about this product is preliminary. The product is under development, is not commercially available in the United States, and its future availability cannot be ensured.