Kidney size worry!!!!

[Radhammamd]

My husband got abdomen and back pain 3years back, we went to do abdominal ultrasound and it showed dilated pericalvIal system And doc told that might be due to the kidney stone that passed and we did repeat ultrasound  and everything was normal. Now after 1year again got pain and found it to be ulcer and now during a normal ultrasound check up found a mildly enlarged fatty liver, enlarged speeln and blood reports are normal  other than uric acid bit high. What worries me is two times when  we did scan also right kidney was 10cm but now it's showing 9.4 after three years. have no idea why it is so? Kindly help and he is prediabetic and obese 33years old that we found now.