Nuclear Renogram of Multi-cystic kidney.
A nuclear renogram is the best imaging study to differentiate a multi-cystic kidney from hydronephrotic kidney. A CAT scan would require sedation, it exposes the child to more radiation and it is more expensive.
Notice that, unlike x-rays, nuclear renogram images show the right kidney on the viewer's right. Multi-cystic kidneys do not function. This study shows that there is no perfusion or renal tubular concentration of the isotope in the left retroperitoneum. Only the right kidney is seen. Most multi-cystic kidneys cause no problems and, therefore, they need not be removed.
