TC(99M)-DMSA IMAGING WITH TOMOGRAPHY IN RENAL-TRANSPLANT RECIPIENTS WITH ABNORMAL LOWER URINARY TRACTS

This study examined whether renal parenchymal imaging using Tc-99m DMSA scintigraphy with tomography is a sensitive measure of renal scarring in renal transplant recipients with an abnormal lower urinary tract and whether such scars correlate with impairment of renal function. Three groups of patients were compared: group 1, patients with an abnormal lower urinary tract and deteriorating renal function (n = 9); group 2, abnormal lower urinary tract and stable renal function (n = 5); and group 3, normal lower urinary tract and deteriorating renal function (n = 8). Eight of the nine patients in group 1 had multiple scars visible on Tc-99m DMSA scans and this correlated with histology when a renal biopsy was performed; the only patient without scars had a transplant glomerulopathy. The presence of scars was associated with either raised intravesical pressures or recurrent urinary tract infections (UTIs). Only one patient in each of groups 2 and 3 had visible scars and both these patients had a history of recurrent UTIs. Patients in group 3 with deteriorating renal function due to chronic rejection documented by biopsy did not have cortical scars visible with Tc-99m DMSA tomography. Tc-99m DMSA scanning with tomography is a useful investigation in the management of renal transplant patients with declining renal function; multiple scars may indicate abnormal lower urinary tract function and are not seen in chronic rejection.