Figure 1.

Study design: (A) surgical liver resection due to HCC at the Vilnius University hospital Santaros Klinikos (Vilnius, Lithuania); (B) specimens tested at the National Center of Pathology (Vilnius, Lithuania); (C) samples stained using a modified Gordon and Sweet’s silver impregnation protocol, combined with Picric Acid–Sirius Red; (D) slides scanned at 20× magnification (0.5 μm per pixel) using an Aperio^® AT2 DX scanner; (E) tissue segmentation using HALO^® AI on the manual annotations; (F) epithelial edge detection and ranking of the hexagonal grid tiles according to tissue class proportions; (G) segmentation of reticulin and collagen fibers using a pretrained convolutional neural network, producing an image of red and green fibers against the black background for viewing and analysis; (H) calculating pixel-level, fiber-level, and image-level features describing the microarchitecture of the fibers within each hexagon; (I) data from individual hexagons are aggregated across predetermined tissue regions to provide case-level features for prognostic modeling.