Everything looks good. The doctor thinks I have a double kidney on the left side, like about 2% of people. Usually nobody knows about it until they're old and getting an ultrasound for some other kidney problem. But here in Germany they do the exam on all newborns, so they turn up this kind of thing more regularly. The doctor isn't worried, because my bladder and ureters all look normal, but we'll have it checked out again at my next doctor visit.