[Advantages of the new radiopharmaceutic agent, 99mTC-mercaptoacetyltriglycine (99mTc-MAG3), in the diagnosis of kidneydiseases. A comparative study with 131I-OIH, 99mTc-DTPA and 99mTc-DMSA].

The properties of 99mTc-mercaptoacetyltriglycine (MAG3), a new radiopharmaceutic for dynamic renal scintigraphy, were assessed in a series of 138 patients with different diseases of the uropoietic system. The physiological values of renographic curves were determined as well as the characteristics of MAG3 excretion, which closely resembled the values for 131I-OIH. On comparing the values of separate MAG3 clearance with standard radiopharmaceutics in 26 subjects examined, very good correlation coefficients (r) were obtained: 0.98, 0.96, and 0.92 for 131I-OIH, 99mTc-DMSA, and 99mTc-DTPA, respectively. Global MAG3 clearance reached 0.64 of the OIH value. The higher quality of scinfigraphic imaging than seen with the substances used so far, the favorable pharmacokinetic properties and the low radiation load (H(E) = 0.51 mSv in adults) of MAG3 determine the indication spheres in which it can best be used to advantage. Of the radiopharmaceutics used to date, MAG3 yields the best results. It can well substitute 123I-OIH, which is not readily available in our conditions, and can thus be expected to be widely used in clinical practice.