InfraReDx Technology: Near Infrared Diffuse Spectroscopy for Coronary Artery Disease

InfraReDx, Inc, a privately held startup based in Burlington, Mass., said on Friday that its angiography laser scanner, intended to characterize fatty deposits in coronary vessel walls, has been approved by the FDA, according to the New York Times.
So we went ahead to check out the technology behind the device, and here’s what we found:

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.
Much of the activity of InfraReDx has been devoted to overcoming the challenges of performing NIR spectroscopy in the human coronary where problems of access, penetration of blood, motion, and the need to scan must be overcome. Fortunately, major advances in lasers and optical devices developed primarily for the telecommunications industry have made it possible to overcome these challenges.
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. It is expected that the initial use of the InfraReDx device will be for diagnosis, which will help in prevention of a second coronary event in the approximately 2 million individuals world-wide who undergo a coronary intervention each year.

The company is also offering the following presentation of its technology: