Many causes of dark urine, kidney disease is certainly one of them.
You will have to wait for your MRI to determine the cause.
Yes, certain NSAIDs are nephrotoxic (damage the kidney) but way down the list of probable causes of kidney damage, so if you have gout, then continue with the treatment. To complicate matters further.......gout can cause kidney disease ( gouty nephropathy).
So pummpy, you are between a rock and a hard thing at the moment.
Drink plenty and wait for the results of your MRI scan.
If you become feverish, and/or shivering, then contact your doctor.