The 125I-Hippuran renogram in rabbit kidneys after graded warm ischaemia

90-minute 99mTc-MDP scintigraphy and 131I-hippuran renography in recently allotransplanted kidneys: evaluation of renal ischemia

Renal ischemic damage in 31 transplanted kidneys was evaluated by renal scintigraphy with 99mTc-methylene diphosphonate and 131I-hippuran renography. The renal uptake of phosphate was monitored for 100 s at 10-min intervals during 90 min following injection. The average uptake of radioactivity in the graft on the 60-, 70-, 80-, and 90-min scintigram was calculated. Grafts with an average uptake of 99mTc-MDP of 150% or below had a significantly more frequent onset of function within the first 3 days following operation than grafts with an average uptake above 150%. Renography was shown to be an equally good method for predicting the onset of function. The success rate (correct prediction of onset of function) was almost equal for the two methods, but in 11 patients the results of the two methods diverged. An obvious degree of overlap limits the usefulness of both methods in any one particular patient. It is concluded that renal scans with 99mTc-MDP and 131I-hippuran renography are complementary in the assessment of ischemic damage following transplantation.

Evaluation of renal ischemia with 99mTc-pyrophosphate

Renal ischemia injury was induced by transient 30-min occlusion of the main artery in five rabbits and by transient 60-min occlusion in four rabbits. The vessels to the contralateral kidneys were ligated in all nine animals and in six additional control rabbits. Renal blood flow was restored immediately following the transient ischemia. Twenty-four hours later, 99mTc-pyrophosphate was injected and renal uptake was monitored for 100 s and 10-min intervals for 90 min following injection. At 90 min postinjection, the animals were killed and the percent injected dose remaining in the kidneys was calculated for three animals in each group. At 60 min postinjection, in vivo activity in the 30-min ischemic kidneys was 2.3 times greater than that of controls, and activity in the 60-min ischemic kidneys 4.6 times greater than that of controls. These results suggest that 99mTc-pyrophosphate scanning may be useful in assessing slight ischemic damage to the kidney.