Comment by dgacmu

No, there literally is always a tradeoff, even in human medicine. I was at my doctor's office yesterday because I'm an idiot and injured myself. I asked about the diagnostic advantages of getting an MRI vs an x-ray for the injury (sciatic pain, probably from an injury to my piriformis; don't snowboard on the east coast). The MRI might have provided better diagnostics, but the x-ray (much faster, at lower cost, but at some radiation exposure to me) ruled out the really serious stuff, and the treatment plan was the same regardless. So: Tradeoff. It was, IMO, both financially and ethically better to use the low-resource diagnostic modality instead of tying up the rare and expensive one, even though it gave me a bit of radiation that in an ideal case I wouldn't have had.