It would be ideal to raise the fee you are paying for the question (you can contact customer service on this), as I have given you an extended amount of aid (much more then your original question price really covers). So, if you can do that or open a new question after leaving feedback for this one, I would be grateful.
Now your results support bacterial presence in the urinalysis but culture doesn’t look to have picked up the agent. You may need to check and see if there is an extended culture in process. Or if he has been on those antibiotics during the time of collection, that may have thrown off these results (and we will just need to treat and recheck the urinalysis at the end of the course). Unfortunately, I cannot comment on the antibiotics you used, as that is not a brand that I am familiar with. But if you can let me know what its generic name is, then I can review that for you.
Otherwise, ultrasound can help find stones +/- blockages if present. Though if the ultrasonongrapher has noted changes, I would believe them on this. My comparing 2 photos just won’t provide as significant analysis compared to the findings of someone who got to scan the kidneys in real time (I do think the second one looks more . Therefore, their view on this has the most weight here.
Finally, thank you for the urine protein to creatinine ratio(UP:UC). It is thankfully normal here (<0.5) and I would consider that valid despite his having an ongoing possible infection (since it would have falsely elevated the results if it were affecting them). Therefore, we'd need to address this infection and then recheck the urine specific gravity in the practice to see if we get it back to normal. If it is, then that is positive despite our likely underlying hydronephrosis causing those kidney and urine changes.
All the best,