Figure 3. Plots and linear regressions of triglyceride content vs. converted fat contents from voltage signals of the reflectance and Raman channels. Shadow areas: 95% confidence bands of linear regressions.
An expert liver pathologist (AES) assessed the whole slide images (as shown in Figure 4A ) and estimated, to the nearest 5% interval, the percent of large droplet MaS and the percent of global (macro- and micro-vesicular) HS. The assessment of large droplet MaS was performed per the most recent Banff recommendations12 for “large droplet fat,” defined as a single droplet expanding the hepatocyte and larger than adjacent cells, with low power determination of the percentage of tissue affected, followed by higher magnification assessment of fatty areas to determine what proportion of steatotic cells meet the definition of “large droplet fat,” and finally adjustment of the low power percentage accordingly. After completion of pathologist estimates, positive pixels (as shown in Figure 4B ) were counted automatically using the Positive Pixel Count algorithm v9 of Aperio ImageScope (Leica Biosystems); this value was normalized by the area assessed to generate a percentage. Areas of artifact, such as tissue folding or coverslip lifting, were manually excluded from the analysis.