Composition of human thrombus assessed by quantitative colorimetric angioscopic analysis

Angioscopy surpasses other diagnostic tools, such as angiography and intravascular ultrasound, in detecting arterial thrombus. This capability arises in part from the unique ability of angioscopy to assess true color during imaging. In practice, hardware-induced chromatic distortions and the subjectivity of human color perception substantially limit the theoretic potential of angioscopic color. We used a novel application of tristimulus colorimetry to quantify thrombus color to both aid in its detection and assess its composition. A series of human thrombus models were constructed in vitro. Spatial homogeneity was ensured by light and electron microscopy. Quantitative colorimetric angioscopic analysis demonstrated excellent measurement reproducibility (mean difference, 0.07% to 0.17%), unaffected by illuminating light intensity (coefficient of variation, 0.21% to 3.67%). Colorimetric parameters C1 and C2 were strongly correlated (r=.99, P