Transplant renography: 99m-Tc-DTPA versus 99m-Tc-MAG3. a preliminary note

^99mTc-MAG3 has been proposed as a replacement for both ¹³¹I-hippuran and ^99mTc-DTPA on clinical grounds. We undertook a prospective preliminary study to ascertain whether ^99mTc-MAG3 works better than ^99mTc-DTPA in the follow up of renal transplant recipients. Seventeen patients (21 renograms each MAG3 and DTPA) were studied, together, with a reference group of 10 patients in whom MAG3 and Hippuran clearance rates were determined simultaneously. As expected, ^99mTc-MAG3 analog images were excellent and ^99mTcMAG3 clearance correlated very well with ¹³¹I-hippuran clearance (r=0.978). MAG3 values were 60% of hippuran values. However, when the corresponding renographic and perfusion findings were faced with different diagnostic challenges, such as post transplant renal failure and rejection, ^99mTc MAG3 did not differ from ^99mTc-DTPA in a significant way. ^99mTc-DTPA was superior to ^99mtc-MAG3 in one case of rejection.