This application is designed to enhance physician understanding and diagnostic accuracy in the interpretation of Tc-99m MAG3 diuretic renography studies. Users can interpret up to ten Tc-99m MAG3 diuretic renography studies and compare their interpretations for each kidney (obstructed, indeterminate, or not obstructed) with the interpretations provided by RENEX, an expert system for diuretic renography, and with the interpretations of three experienced readers. The website assumes users are referring physicians, residents, radiologists, or nuclear medicine physicians with prior exposure to Tc-99m MAG3 diuretic studies. First time users need to create an account (user name and password, upper right hand corner) to access the studies. This educational application was developed because a large majority of the estimated 590,000 radionuclide renal scans performed annually in the United States are conducted at sites that perform fewer than 3 studies per week. Due to the relative infrequency of renal studies, some individuals may fail to acquire the expertise needed to provide a competent interpretation. Limited training and experience may discourage the use of the procedure, lead to incorrect scan interpretation and negatively impact patient care.