TABLE 1.

System used to score the different pathology types

Pathology type	Score	Scoring criteria
Edema	0	Normal appearance
	1	Minimal focal perivascular or interstitial
	2	Mild focal perivascular or interstitial
	3	Moderate focal to locally extensive, perivascular, and interstitial
	4	Marked with a >25% section affected, focally to locally extensive, perivascular, and interstitial
Hemorrhage	0	None
	1	Mild (focal)
	2	Moderate with up to 25% section affected, mild/focal or locally extensive
	3	Marked with a >25% section affected, focal to locally extensive
Infiltrate	0	None
	1	Minimal with less than three vessels affected, up to three layers of cells surrounding
	2	Mild with 3 to 10 vessels, up to three layers, no interstitial infiltrates
	3	Moderate with 10 or more vessels, three layers or more, focal/patchy interstitial
	4	Marked with numerous vessels and/or extensive areas of interstitial infiltrates
Necrosis	0	None
	2	Mild with focal necrosis and a <10% section affected
	3	Moderate with mild/focal to locally extensive, >10% to 25% affected
	4	Marked with focal to locally extensive, >25% affected, large areas of consolidation