title: Localized measurement of optical attenuation coefficients of atherosclerotic plaque constituents by quantitative optical coherence tomography.
abstract: Optical coherence tomography (OCT) is a novel, high-resolution diagnostic tool that is capable of imaging the arterial wall and plaques. The differentiation between different types of atherosclerotic plaque is based on qualitative differences in gray levels and structural appearance. We hypothesize that a quantitative data analysis of the OCT signal allows measurement of light attenuation by the local tissue components, which can facilitate quantitative spatial discrimination between plaque constituents. High-resolution OCT images (at 800 nm) of human atherosclerotic arterial segments obtained at autopsy were histologically validated. Using a new, simple analysis algorithm, which incorporates the confocal properties of the OCT system, the light attenuation coefficients for these constituents were determined: for diffuse intimal thickening (5.5 +/- 1.2 mm(-1)) and lipid-rich regions (3.2 +/- 1.1 mm(-1)), the attenuation differed significantly from media (9.9 +/- 1.8 mm(-1)), calcifications (11.1 +/- 4.9 mm(-1) ) and thrombi (11.2 +/- 2.3 mm(-1)) (p < 0.01). These proof of principle studies show that simple quantitative analysis of the OCT signals allows spatial determination of the intrinsic optical attenuation coefficient of atherosclerotic tissue components within regions of interest. Combining morphological imaging by OCT with the observed differences in optical attenuation coefficients of the various regions may enhance discrimination between various plaque types.
authors.affiliation: Laser Center, Academic Medical Center, Amsterdam, The Netherlands. f.j.vandermeer@amc.uva.nl
authors.forename: Freek J
authors.initials: FJ
authors.lastname: van der Meer
authors.forename: Dirk J
authors.initials: DJ
authors.lastname: Faber
authors.forename: David M
authors.initials: DM
authors.lastname: Baraznji Sassoon
authors.forename: Maurice C
authors.initials: MC
authors.lastname: Aalders
authors.forename: Gerard
authors.initials: G
authors.lastname: Pasterkamp
authors.forename: Ton G
authors.initials: TG
authors.lastname: van Leeuwen
mesh_terms: D000465:Algorithms; D050197:Atherosclerosis / Q000473:pathology* / Q000503:physiopathology*; D016893:Carotid Stenosis / Q000473:pathology* / Q000503:physiopathology*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods; D066298:In Vitro Techniques; D016247:Information Storage and Retrieval / Q000379:methods; D008027:Light; D008955:Models, Cardiovascular; D010363:Pattern Recognition, Automated / Q000379:methods; D015203:Reproducibility of Results; D012542:Scattering, Radiation; D012680:Sensitivity and Specificity; D041623:Tomography, Optical Coherence / Q000379:methods*