Increased perinephric activity in 99mTc-DTPA studies of renal transplants.

All 99mTc-DTPA studies of renal transplant patients whose grafts infarcted during a three-and-one-half-year period were reviewed. Four patients demonstrated absent renal perfusion and clearance and absent bladder activity. Three of these exhibited increased perinephric 99mTc-DTPA activity and never regained renal function. The fourth patient did not demonstrate increased perinephric activity, and some return of graft function appeared in a subsequent 99mTc-DTPA study. The pathogenesis of increased perinephric activity is unknown, but may signify renal infarction, and its absence may indicate potential renal viability.