Quantitation of ischemic injury with 99mTc-HEDP in experimental acute tubular necrosis

Incremental ischemic injury was induced in rabbits by transient occlusion of the renal artery. Renal localization of 99mTc-HEDP was quantitated in ischemic and normal kidneys at fixed intervals following restoration of blood flow. Creatinine clearance and microscopic evaluation of renal structure were determined concurrently with scintigraphic studies. There was a sequential reduction in creatinine clearance and an increase in tubular necrosis with prolongation of the ischemic period. 99mTc-HEDP localization in ischemic renal tissue was dependent on the degree of renal injury, ranging from twice normal with minor injury to a nine-fold increase with the most severe ischemic changes. The increased accumulation was demonstrable for longer periods with increasing ischemic injury. Considerable recovery of renal function was apparent in all groups by one week. 99mTc-HEDP may be useful in evaluation of renal failure secondary to ischemic injury.