I have no experience, other than a similar 'waiting game'... to hear from the Doctor, after what was a very uncomfortable reaction from the clinician performing a test on my infant.....
., which is why I google'd this MDKD condition. I don't know what any of this means, but there are examples of Kidney ultrasounds on the 2nd kidney for such MDKD cases..where the 2nd kidney has what look like the black holes you describe.... meanwhile it is really one of these other treatable conditions..... so I don't think what you saw can be interpreted wih any certainty other than something is going on with the 2nd kidney.
So for some hopeful thinking, here are some excerps from articles on google about the 2nd kidney of an MDKD case:
"the normal kidney can have other associated conditions such as vesico-ureteral reflux, uretero-pelvic junction obstruction, or uretero-vesical junction obstruction. The risk of an associated abnormality is as high as 51 percent. These are all surgically correctable problems and in some cases may resolve with observation alone. "
Also spotted , on google, an Abstract on this issue...t I think means it can be hard to see the difference between an MDKD condition and one of these other treatable issues:
"Diagnosis is usually easy as MDKD has in the vast majority of cases a striking ultrasound appearance including enlargement of the kidney and multiple renal cysts. However, differentiation from obstructive uropathy may be difficult, and we made a total of five erroneous diagnoses. "
Also, here is a link on facebook that I stumbled on ... seems to be lots of people talking about their experiences with the disease ... maybe you can reach out to some of them ...
http://ja-jp.facebook.com/group.php?gid=42415440788&v...