Figure 1.

A - Portal tract (yellow) and portal structures (hepatic artery, red line; bile duct, green line) and hepatic artery-bile duct distance (black line) are measured as illustrated above. Note the presence of ductules located at the periphery of the portal tract (arrows) (hematoxylin and eosin, 400X magnification). B- In incomplete portal tracts, a hepatic artery branch >20 μm can be considered “unpaired” (arrow) if a bile duct is not present within a radius of 10 hepatic artery diameters from the edge of the arterial profile, as illustrated. In the example above, the arterial profile located at the center of the biopsy core can be labeled as “unpaired”, while the artery closer to the biopsy edge cannot. Abbreviations: HA, hepatic artery; PV, portal vein (Trichrome stain, 400X magnification).