The new cardiac catheter
Courtesy of Marcu Lab/UC Davis

UC Davis team creates better cardiac catheter by combining ultrasound and light

October 06, 2017
by Lauren Dubinsky, Senior Reporter
A team at UC Davis has invented a new cardiac catheter that combines intravascular ultrasound and fluorescence lifetime imaging to identify plaques that may cause a heart attack.

“Integration of FLIm with IVUS can improve the diagnostic ability of IVUS, the most widely used intravascular imaging technique in cardiology, and create new paradigms for the diagnosis and management of atherosclerotic cardiovascular disease,” Laura Marcu, professor at UC Davis, told HCB News.

Cardiologists can examine blood vessels for constricted regions with contrast-enhanced angiography, but it could miss dangerous plaque buildups since plaque doesn’t always result in constricted vessels. IVUS is capable of penetrating the buildup to determine its depth, but it’s unable to identify some of the finer details of plaque rupture risk.

Pairing IVUS with FLlm in a single catheter probe makes it possible to image the small arteries in a living heart. The new catheter can also retrieve structural and biochemical information on arterial plaque, which could more accurately predict heart attacks.

An optical fiber inside the catheter sends short laser pulses to surrounding tissue, which fluoresces with tiny flashes of light in return. Tissue such as collagen, proteins and lipids emit different amounts of fluorescence.

“FLIm can improve the functionality of conventional IVUS — provided that the two techniques are synergistically integrated in an imaging catheter,” said Marcu.

In the development process, Marcu and her team had to overcome a couple of obstacles. They had to design and build a hybrid catheter that is small enough to image coronary arteries and come up with solutions that make FLlm fast enough to acquire data in a few seconds from a segment of the coronary artery in the beating heart.

The team outlined how they were able to overcome those challenges in a study that was published in Scientific Reports.

The new catheter has been tested in living swine hearts and samples of human coronary arteries. Marcu’s team is currently working to obtain FDA approval to test the catheter on human patients.