Fig. 3.

SWIR absorbance spectra [unitless, defined as 1/log(reflectance)] of human carotid atherosclerotic plaques (fibrous, dotted line; calcified, dashed line; and soft, solid line), measured ex vivo using a fiber probe and spectrometer.²² The spectra exhibit features of absorption from water (peaks near 1450 and 1950 nm) and lipids (peak near 1200 nm). This work suggests that SWIR may have the potential to differentiate between vulnerable plaque and more stable forms of plaque. (Figure reproduced with permission.)