<s>[INST] Good morning.  My 11 year old son was found to have renal ultrasound findings of mild pelvocalyceal fullness in both kidneys.  Per DMSA renal scan, the interpretation was:  "Diminished tracer uptake in superior portion of both kidneys probably due to previous pyelonephritis.  What does it mean?  Thank you.  From a Worrying Mother [/INST] Good day, and thank you for being with Chat Doctor ! It means that because of previous infection the upper part of your sons' kidney is not functioning very well. I suggest repeating the same scan 3 months after and if infection is still present, it should be managed properly. I hope I have answered your question satisfactorily, and please consider a 5-Star rating for my answer. Thank you very much. </s>