Kidney disease and MRI with dye

My GFR is 47 for my single kidney. Functioning at less than 50 percent..
Last week, while doing a flat xray of my shoulder because I have a shoulder impingement (rotator cuff issue) going on.. they spotted a cyst/tumor on the bone. I asked if this were due to the injury and just a pocket of fluid from a tear.. The answer to that was "No.. This is actually on or in the bone."

My question is...Has anyone had this before and can share with me their experience?

Also.. The dilema right now, is beause of my kidney function is getting worse, my PCP will not approve the MRI using the dye, as the radiologist wants to have done to see this area more clearly. At my healthiest, it functions at 54 percent, never any better than that.
I know that this dye can do more damage and possible kidney failure... my thought was to put me in the hospital, pump me full of IV's for hydration.. do the test the next day.. continue to pump me full of IV's, to make sure the dye clears through my kidney 100%. Am I thinking a simple solution would still be detrimental to my health and kidney???
Why my hydration is so important is because I have had an Ileostomy for 26 years and walk a tightrope daily of keeping my hydration in balance. I can not drink tons of fluids to rehydrate, because it just comes out my pouch first, before it ever hits the kidney. I have Short Gut Syndrome.

Thanks for your time, suggestions.
Mare