>>49893058Uhh, basically different parts of the bodies have different thicknesses and densities, so you x ray them with different settings on the machine.
kV is your voltage (basically your penetrative power), mAs is the amount of x rays you're putting out. The higher your kvp goes the lower the image contrast is (meaning your image has more shades between black and white) so generally you only want that when there is a very slight difference between the healthy and pathological tissue you're looking at. When it comes to bones, you want higher contrast (lower kvp) because the difference between healthy bone (very dense) and a fracture (literally empty space) is quite dramatic, so having it pop out makes it a lot easier for the radiologists to see.
The technique used in this image has super high kvp but low mAs, and that's the kind of technique you would really only use for a chest x ray, so you can see the subtle little things like fluid in the bronchi and the like. That kind of stuff would get completely burnt out of the image if you used a low mAs/high kvp.
So I have to assume that was actually just a chest X ray and not something specifically to do with the posterior spinal rods this guy has, because you're getting way more info about his lung health (looking good by the way) compared to anything about how the rods and his spine are doing.
