cloudy kidney?

My mom went to the emergency room earlier because she was having severe pain in her left side. I assumed she was passing a stone or ruptured a cyst. She went in and they did blood and urine which came back normal, but when they did a ct scan the doctor said her left kidney came back cloudy
(like it had a film on it) but they did a renal function and it came back normal.

I've tried googling and everything keeps coming up cloudy urine and kidney stones/infections, so I'm just wondering if anyone has ever heard of a cloudy kidney on a ct scan or if they might know what it is? TIA