That's odd that the radiologists do not mention it. I had a cyst found on my kidney during a CT scan looking for other stuff 6-7 years ago (it ended up being nothing), but it gets noted on every single CT scan that I've had since.
I read that when you have kidney stones, only one kidney produces them. If you lose that kidney, the other one starts producing stones. It makes one wonder how your system directs the minerals to the one kidney. Our systems are beyond miraculous.