Large Renal Cyst Underestimates Split Function on Diuretic Radionuclide Renal Scan

Radionuclide renal scan performed with (diethyle triamine penta acetic acid (DTPA), ethylene dicysteine (EC), mercaptoacetyltriglycine (MAG3), and dimercaptosuccinic acid (DMSA) provides split function between the two kidneys. Hence it is a valuable method to evaluate percentage function prior to nephrectomy. Nephrectomy may be done in a prospective renal donor or it may be done for a diseased kidney. In either case, the nephrologist/ urologist must ensure that the remaining kidney is able to sustain renal function post nephrectomy. We present a case where conventional renal scan had underestimated the split function due to a large posterior cortex cyst accounting for attenuation of radionuclide photons. Repeat scan in anterior view had eliminated this erroneous result. We could not find any such reported discrepancy despite extensive web-based search. World J Nephrol Urol. 2021;10(1):12-14 doi: https://doi.org/10.14740/wjnu422