Laser-Based Camera Improves View of Carotid Artery

A scanning fiber endoscope (SFE) has been used to acquire high-quality images of possible stroke-causing regions of the carotid artery that may not be detected with conventional radiological techniques.

Scanning fiber angioscopic images with red reflectance for structural images (left) and blue fluorescence for label-free biochemical contrast (right). Images demonstrate multiple atherosclerotic lesions with very low fluorescence in the blue spectrum in comparison to the surrounding healthy artery. Courtesy of Michigan Medicine.

Originally designed for early cancer detection, researchers from Michigan Medicine at the University of Michigan used the instrument differently by illuminating tissues with multiple laser beams and digitally reconstructing high-definition images to determine the severity of atherosclerosis and other qualities of the vessel wall.

"The camera actually goes inside the vessels," said Luis Savastano, a Michigan Medicine resident neurosurgeon. "We can see with very high resolution the surface of the vessels and any lesions, such as a ruptured plaque, that could cause a stroke. This technology could possibly find the 'smoking gun' lesion in patients with strokes of unknown cause, and may even be able to show which silent, but at-risk, plaques may cause a cardiovascular event in the future."

Strokes and heart attacks often strike without warning. This new application could one day help physicians know who is at risk for a cardiovascular event by providing a better view of potential problem areas. It can also assist neurosurgeons with therapeutic interventions such as stent replacement, releasing drugs and biomaterials, and helping with surgeries.

The SFE uses fluorescence indicators to show key biological features associated with increased risk of stroke and heart attacks in the future.

"The ability to identify and monitor the biological markers that render a plaque unstable and at risk for rupture could enable the detection of individuals within high-risk populations who are most likely to suffer from cardiovascular events, and therefore benefit the most from preventive treatment during the asymptomatic stage," said B. Gregory Thompson, a professor of neurosurgery at the University of Michigan Medical School.

A senior author of the paper, Thompson said, "In addition, plaque-specific data could help physicians modulate treatment intensity of atherosclerosis, which is currently based on systemic surrogates such us cholesterol and blood sugar levels and occurrence of cardiovascular events such as stroke or myocardial infarction."

All research is in the pre-clinical phase. The proof-of-concept results for this imaging platform for atherosclerosis has been published in the journal Nature Biomedical Engineering (doi:10.1038/s41551-016-0023).