Contrast-induced nephropathy is essentially fake news. If in doubt, give contrast. And then give some more. The risk of missing a key diagnosis or not doing a life saving procedure far far outweighs the benefit of potentially reducing theoretical risks of damaging the kidney.
For those outside of Radiology who don't know, contrast induced nephropathy for yrs now,felt to be somewhere between a questionable entity, possibly non-existing entity. if a pt w renal failure needs an exam, dangers of missing a dx are often> than CIN risk