Imaging of atherosclerotic plaques by Optical Coherence Tomography (OCT)

Optical Coherence Tomography (OCT) is an imaging technique that measures the intensity of light back scattered from subsurface tissue structures with a very high resolution. This report describes the qualitative and quantitative correlation of OCT and histology measurements for plaque presence and thickness of caps overlying atherosclerotic plaques, respectively. Imaging of samples (n = 12) was performed from the luminal side with 1300 nm 1 mW or 10 mW light sources, with coherence lengths of 21 and 16 μm, respectively. Samples were histologically processed and stained with H&E, EvG and picro-sirius red (PSR) and histological and OCT images were matched. For each sample, the presence of plaque was assessed and the minimal cap thickness was measured by means of histomorphometry and OCT. We found a sensitivity of 6/6 and a specificity of 5/6 for detection of plaques with OCT. Quantitative analysis showed a strong and significant correlation between OCT and histology cap thickness measurements (R2 = 0.968). Thus, OCT is a sensitive method for detection of plaques, is quantitatively comparable to histology and holds promise as a high-resolution diagnostic tool for visualization of plaque cap thickness.