My son, 7 weeks old, has mild hydronephrosis in his left kidney (APD 9.9mm) as per usg done at 6 weeks of age. We went for EC renal scan which shows left kidney functioning at 53% , kidney appears normal in size andlocation. Perfusion and cortical uptake are preserved. Photopenic area is seenin the PCS, filling up in serial images and showing no significant drainagetill the completion of dynamic study. Significant tracer retention is seen inthe PCS in delayed image acquired at 4 hrs. Right kidney is absolutely normal, functioning at 47% What are the chances of this resolving without surgery? If surgery is must, then how long can it be delayed? Who is best the paediatric surgeon in Delhi/Noida?