Near Infrared Diffuse Spectroscopy Laser Targets Coronary Artery Disease


April 29, 2008

InfraReDx Inc. developed the LipiScan Coronary Imaging System that is intended to characterize fatty deposits in coronary vessel walls using near infrared diffuse spectroscopy.

Near-infrared [NIR] diffuse reflectance spectroscopy is a highly developed technique that is in common use in fields such as chemistry and pharmaceutical development to identify the chemical composition of substances. The identification of the chemicals present is based on the differential absorption of light in the NIR spectrum by different molecules. An important feature of near-infrared light is that it can penetrate tissue and can therefore identify a tissue despite the presence of blood between the detector and the target. This is an important advantage for imaging within the human coronary artery.

The InfraReDx system consists of a laser light source, an automated pullback and rotation device and a small fiberoptic catheter. While the catheter is similar in size and ease of use to an intravascular ultrasound catheter, the information it provides is quite different since it is based on an optical rather that an ultrasonic signal.

The NIR system obtains signals from patients that are analyzed with algorithms validated by comparison to tissue histologic findings in ex-vivo coronary specimens. It is therefore possible to perform a pullback in a patient’s artery, and provide an image of the NIR signals which indicate the presence of lipid and other chemicals of interest. It is expected that these images, which are called Intravascular Chemograms, will provide information to interventional cardiologists to help in the care of patients already undergoing cardiac catheterization for a coronary event.

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