"The most popular method is probably not the best method, because the best method is hard to use," said Carl Wesolowski, explaining their new approach is much simpler and gives "best method" results. The team‘s work is described in a paper published in the March 2016 issue of the European Journal of Nuclear Medicine and Molecular Imaging. How well each kidney is functioning -- something called split renal function -- is critical knowledge for anyone planning to donate a kidney or to guide doctors‘ decisions for surgery and other medical treatments. "Most of the time kidneys are 50-50 in terms of their split function," explained Carl Wesolowski. "Sometimes having different sized kidneys is just an act of nature -- you can be born that way -- and you can have a small kidney that‘s normal and a big one that is normal as well. But sometimes, each kidney can function differently due to an illness such as high blood pressure, a cancerous tumor or a urine blockage. A kidney stone, for example, can prevent urine from draining properly, causing it to build up in the organ and eventually stopping it from working."