THE IMPORTANCE OF TC-99(M)-DMSA RENAL SCINTIGRAPHY IN THE FOLLOW-UP OF ACUTE PYELONEPHRITIS IN CHILDREN - COMPARISON WITH UROGRAPHIC DATA

At present, Tc-99(m)-dimercaptosuccinic acid (DMSA) renal scintigraphy is the most sensitive examination for the detection of parenchymal da mage during acute pyelonephritis (APN) in children. This prospective s tudy had three aims: (1) to evaluate the medium-term evolution of the scintigraphic abnormalities, to find a prognostic criterion of scintig raphic evolution; (2) to assess the correlation between the severity o f early or late scintigraphic damage and selected clinical factors; an d (3) to compare the permanent scintigraphic renal scars with intraven ous urography (TW) 2 years after the acute infection. Seventy-four chi ldren (mean age 32 months), presenting with a first clinical episode o f pyelonephritis and an initial scintigraphic abnormality, were includ ed in the study. Patients with a history of urinary tract infection (U TI), uropathy other than vesico-ureteral reflux (VUR) and a relapse of acute pyelonephritis were excluded. All children underwent control sc intigraphy (mean 9 months after APN) and 43 had an NU (mean 26 months after APN). Fifty-seven children (77%) still have scintigraphic abnorm alities of varying severity (7 atrophic kidneys). Initial relative DMS A uptake of less than 45% results in a worse scintigraphic prognosis. The age of the child has no bearing on the severity of the initial ren al involvement or on the evolution of the scintigraphic abnormalities. The rapid introduction of antibiotics (<12 h) significantly improves the scintigraphic prognosis (P < 0.01). The presence of reflux (n = 39 ) leads to more serious initial damage, but we did not find any effect on later evolution in this study, in which all reflux was low grade i n nature. Among the 43 children who had an IVU, 5 showed typical urogr aphic and scintigraphic renal scars in the corresponding region and 38 showed a normal IVU with 28 cases of scintigraphic abnormalities. A D MSA scan is more sensitive than TW for the detection of renal scarring after a first episode of APN. ((C) 1998 Lippincott-Raven Publishers).