Greetings from radiology. Since EM didn’t match 500 residents this year, and didn’t match 250 residents last year, you’d think they’d be desperate for any warm body. That being said, if you can’t start, think of it as a sign from God— EM sucks. Just find a prelim spot and do radiology, anesthesia, pathology, or PM&R. Even Family Med is better than EM, seriously. You’ll be OK no matter what. Stay strong and don’t worry.
I am a radiologist— used to do voiding cystourethrograms (VCUGs) in residency routinely, except I had to place the catheter myself. Hated doing them. Anyhow, this child’s problem is an incompetent valve from the urethra into the urinary bladder, so urine is flowing upstream back into the kidney. The dilation of the renal calyces means it’s a lot. This is the reason the UTIs are recurrent. A lot of the comments here are addressing the UTIs, but that is not the problem, but a result of the vesicoureteral reflux.
There is a good comment below by u/rayshade with more information.