kidney size & kidney problems

I should note that I was born with urinary reflux, and it was bilateral.

One kidney was grade III, and the other was grade IV.  

I had surgery to correct it when I was 12 (I am 24 now), but I started experience chest pain (still do), high blood pressure and tachycardia (still have that as well)

Doc sent me for an Echo & pelvic/renal ultrasound.

My right kidney is 16 cm & 75 cubic centimeters in volume, and my left is 10 cm and 45 cubic centimeters in volume.

Bladder shows PVR of 52.5 mL (the amount of urine left in the bladder after going to the bathroom), and I get recurrent UTI's and what not.

Ultrasound shows what looks like stones in the bladder, though I won't know for sure until I see the radiology report.

Why would my right kidney be bigger? Might I have hydronephrosis?

Also, is >50 mL PVR considered abnormal?