Fig. 4
Subject 13: Two minute sequential images following the administration of [99mTc]Tc-MAG3 (320 MBq) and [99mTc]Tc(CO)3(NTA) (54 MBq) with the corresponding renogram curves. The relative uptake of the left kidney was 50% for both tracers. The T1/2 of the left kidney for MAG3 was > 50 min and the 20 min/maximum count ratio was 0.79 compared to a T1/2 of 7 min and 20 min/max count ratio of 0.34 for NTA. The images, renogram curve, prolonged T1/2 and elevated 20 min/max ratio of the MAG3 study might be interpreted as indeterminate for obstruction or representing an obstructed left kidney. In contrast, the combination of a normal T1/2, equal uptake by the two kidneys and a normal 20 min/max ratio for NTA study excludes left kidney obstruction