A new probe that can image both the structural anatomy of artery walls as well as the biological activities within them could one day help detect blood clots before they cause problems.
“Now we’re going to be able to more precisely predict which plaques are going to cause symptoms and heart attacks and sudden cardiac death,” says Farouc Jaffer, director of the Cardiovascular Molecular Imaging Program at the Massachusetts General Hospital’s Center for Molecular Imaging Research in Boston.
Stent-related clotting, which often leads to full-blown heart attacks, occurs in at least 2% of people who have the tubes implanted into their coronary arteries. And with more than a million stents implanted each year in the US alone, researchers are always looking for better ways to find detect clotting when the plaques are still small and relatively complication-free.
To this end, Jaffer, together with Guillermo Tearney and Hongki Yoo from Mass General’s Wellman Center for Photomedicine, created their new catheter-based device by combining two microimaging techniques that doctors have traditionally performed separately. The first, called ‘optical frequency domain imaging’, provides a high-resolution structural view of the arterial wall structure; and the second, called ‘near infrared fluorescence’, detects molecular information from tissues tagged with fluorescent markers.
Reporting online this week in Nature Medicine, the researchers showed in rabbits and in cadaver tissue taken from people with blocked stents that the new device can accurately identify areas of active inflammation and clot-inducing fibrin deposition with exquisite three-dimensional and technicolor detail.
Because the fiberoptic probe is so similar to existing catheters that only show detail at one level or ‘modality’, Tearney says that it should be pretty straightforward to get the new device into clinical use. “We believe that this catheter — which looks to the end user just like a standalone catheter, but now provides two modalities — should be readily adaptable to human use very quickly,” he says.
Above, you can watch a short video in which Tearney explains the kinds of images and animations that the device produces.