Patent ID: 8000774

Claim:
A method for locating a vascular obstruction within a vessel, the method comprising: determining spectral responses of a wall of the vessel through an intervening fluid by inserting a catheter into the vessel, irradiating the wall of the vessel via a head of the catheter and detecting returning light while rotating the head within the vessel and drawing the head through the vessel to generate, from the returning light, a spectral image of the wall comprising a plurality of pixels, and defining spatial regions of the spectral image relative to the rotation of the head and longitudinal position of the head in the vessel; calculating average spectral responses at multiple wavelengths for pixels within each of the spatial regions of the spectral image analyzing fluctuations in the measured spectral responses within each of the spatial regions by comparing a measured spectral response of each pixel within the region with at least one threshold derived from the average spectral response; locating the vascular obstruction based on the spatial fluctuations in the measured spectral responses by indentifying spatial regions in which the measured spectral responses exceed the threshold; and providing information indicating the location of the spatial region of the vascular obstruction to a user via a user interface.