60-year-old female undergoing radiation therapy. Evaluate for split renal function. The posterior abdominal radionuclide angiogram demonstrates prompt, symmetrical perfusion of the kidneys.Sequential renal images show the left kidney to be of normal size and morphology. There is decreased size of the right kidney, particularly of the right lower pole, as seen on prior MRI and which may be due to postsurgical change versus scarring from prior infection or infarct.There is prompt uptake and excretion of the radiopharmaceutical by both kidneys. The estimated contribution of the right kidney to total renal function is 42% and that of the left kidney is 58%. On washout phase, there is pooling of radiotracer in the dilated right renal pelvis with delayed clearance from the proximal right collecting system. The half time of tracer clearance from the left kidney is 12.2 minutes and that from right kidney is 185 minutes. As a result, partial obstruction cannot be excluded.
1. Mildly decreased contribution of the right kidney to total renal function as detailed above.2. Delayed washout of radiotracer from the dilated right renal pelvis, and as a result, partial obstruction cannot be excluded.