Tissue Autofluorescence is Correlated With Intima and Media Thickness in Atherosclerotic Human Aorta

This study identifies fluorescence excitation-emission pairs correlated with atherosclerotic pathology in an ex vivo human aorta. Fluorescence spectroscopy, wide-field fluorescence imaging, gross pathologic and histologic evaluation of ex vivo cadaveric human aorta are performed. A matrix of Pearson correlation coefficients are determined for the relationship between relevant histologic features and fluorescence intensity for 427 excitation-emission pairs. A multiple linear regression analysis indicates that tryptophan and elastin fluorescence intensity predicts 58% of the variance in intima thickness (R-squared = 0.588, F(2, 18) = 12.8, p = 0.0003), and 48% of the variance in media thickness (R-squared = 0.483, F(2, 18) = 8.42, p = 0.002). Excluding lesions identified as necrotic lipid cores on histology from analysis, a combination of tyrosine, tryptophan, collagen and elastin autofluorescence predicted 86.0% of the variance in intima thickness (R-squared = 0.8598, F(4, 13) = 19.9, p = 1.87 × 10^-5) and 51.8% of the variance in media thickness (R-squared = 0.518, F(4, 13) = 3.49, p = 0.0382).