Multiple Out Of Actions and Lasting injuries

The Core Rulebook states that when an injury roll results in more than 1 OOA, a separate roll on the Lasting Injury table is made for every OOA result. But what is an injury roll? Is it the sum of all injury dices resulting from all unsaved wounds? Or is it the injury dice from one wound (and potentially multiple damages)?

To clarify, consider the following example: My fighter shoots an enemy fighter with a scattershot, Damage 1 weapon. The hit is successful, I roll 1d6 for determining the number of wounds and I obtain 6. My opponent saves 2 of them, I then have 4 injury dice. Let's say I obtain 3 OOA. Do I have to roll 3 times on the Lasting Injury table (and then the 3 OOA are considered as 1 injury roll)? Or since the weapon is Damage 1, these are 3 separate injury rolls and then, I apply the first one, the opponent's dude goes OOA, I roll once one the Lasting Injury table and the last 2 OOA do not have any effect?

Hope it's clear enough! Thanks for your help!!