This website is designed and structured to enhance physician understanding and diagnostic accuracy in the interpretation of Tc-99m MAG3 diuretic renography studies using RENEX as an educational tool. RENEX is decision support software designed to interpret MAG3 diuretic studies. The website assumes the user is a referring physician, resident, radiologist or nuclear medicine physician with prior exposure to Tc-99m MAG3 diuretic studies.

The 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 in many institutions, some nuclear medicine residents may fail to acquire the expertise needed for a competent interpretation.  This problem is far more acute for radiology residents and general radiologists whose total nuclear medicine training is typically limited to 3-4 months.  Limited training and experience may discourage the use of the procedure, lead to incorrect scan interpretation and negatively impact patient care.

To address this issue, we developed software (RENEX) to interpret Tc-99m MAG3 diuretic renal scans using quantitative data derived from the renogram [1-3].  RENEX is a heuristic or rule based decision support system that interprets each kidney as obstructed, indeterminate, or not obstructed, indicates the level of confidence in that interpretation and provides the rationale (rules) supporting the interpretation [1, 4].  Although RENEX was designed for separate baseline and furosemide acquisitions, its rational will often be relevant for acquisition protocols that administer furosemide before or concurrently with Tc-99m MAG3.

RENEX has been shown to have a diagnostic accuracy approaching that of experts and a significantly greater diagnostic accuracy than nuclear medicine resident physicians with one full year of training; when the residents were given access to the scores and rationale provided by RENEX and asked to reinterpret the cases, their diagnostic accuracy significantly improved [5].  In a follow-up study, RENEX outperformed a second group of experienced nuclear medicine residents and, again, the diagnostic accuracy of the residents improved with access to RENEX [6]. To determine if the second group of residents had learned from their initial experience with RENEX, they interpreted a new set of cases without access to RENEX and showed a significant improvement in their agreement with experts [6].

The website is organized into Home, Introduction, Case Review, RENEX and Expert Interpretation Pages. The Introduction Pages contain a sample study with an explanation of relevant renogram parameters and an introduction to RENEX.  The Case Review Page contains a link to 10 Tc-99m MAG3 diuretic studies.  The studies may be reviewed in one or more settings and in any order.

The reader selects a study and enters an interpretation for each kidney (not obstructed, indeterminate, or obstructed) using the provided numerical scoring system.  Once the scores are entered and saved, the RENEX Interpretation Page becomes available; this page provides the RENEX scores and RENEX rationale.  The website then asks the reader to enter a 2nd set of scores for each kidney.  The reader has the option of modifying the original scores based on the input from RENEX or re-entering the original scores if the interpretation is unchanged.  Once both kidneys have been scored a 2nd time, the reader is given access to the Expert Interpretation Page; this page contains the scores and comments of 3 experienced readers.

NOTE: It is important to view the website in full screen mode for optimal function.