MRI scans to be made safe for pacemakers

More than 2 million Americans depend on pacemakers or defibrillators to keep their hearts beating right, but those lifesaving implants come with a price: They're not allowed in MRI machines, leaving these patients out of luck if they later need scans to detect cancer, stroke or myriad other ailments. That's poised to change.

Doctors at a handful of hospitals are beginning to give MRIs to certain patients despite those implants — in careful experiments of ways to shield the heart devices from potentially deadly meltdowns or misfires. And the first human study of a pacemaker specially designed to withstand MRIs is expected to begin by year's end.