by Dr. D Wyner of the University of Florida
Nuclear medicine scanning (commonly referred to as a MAG-3 scan) is excellent at determining glomerular or tubular function. 99-Technetium is the radioactive agent that is coupled to either DTPA (100% filtered, 0% secreted by the tubules) or MAG-3 (97% secreted by tubules, 3% filtered by glomerulus) depending on the structure you wish to analyze. Nuclear medicine images of the kidney are taken from the posterior view, so the right kidney is on the right side of the image. Scanned images then measure the number of radioactive counts over time in each region of interest (renal artery, cortex, renal pelvis, proximal ureter, distal ureter, bladder). These pictures over time can help you determine if there is poor uptake, obstruction, or both.