title: Functional parameters and 99mtechnetium-dimercaptosuccinic acid scan in acute pyelonephritis.
abstract: The diagnostic value of 99mtechnetium-dimercaptosuccinic acid (DMSA) scintigraphy, ultrasonography and renal functional parameters [urine N-acetyl-beta-D-glucosaminidase (NAG)/creatinine and urine albumin/creatinine quotients] in acute pyelonephritis (APN) were studied in 39 children (28 girls, 11 boys, median age 9 months, range 2 weeks to 9.4 years, 28 patients < 1 year, 11 patients > 1 year) with first-time urinary tract infection. Ultrasonography of the urinary tract was performed on admission and together with DMSA scintigraphy (< 10 days from admission). Urine NAG/creatinine and urine albumin/creatinine quotients were measured daily and after 6-8 weeks. Ultrasonography revealed abnormalities in 12 of 39 (31%) patients [11/32 patients (34%) with positive DMSA scintigraphy], while DMSA uptake defects were present in 32 of 39 (82%) patients [21/28 < 1 year (75%), 11/11 > 1 year (100%), P = 0.08]. Urine NAG/creatinine and urine albumin/creatinine quotients were significantly higher in children < 1 year with APN, as well as in non-renal fever controls, than in older children. However, in both age groups the urine NAG/creatinine and urine albumin/creatinine quotients were significantly higher in APN than in non-renal fever. The urine NAG and albumin excretion decreased rapidly after the initiation of antimicrobial therapy and had normalized at 6-8 weeks. The size and grade of the DMSA uptake defect (DMSA score) did not correlate with duration of disease at admission, maximum C-reactive protein or maximum fever. The urine NAG/creatinine quotient in the children < 1 year showed, however, a significant correlation with the DMSA score (r = 0.58, P < 0.05), while no correlation was found in the older children. We conclude that DMSA scintigraphy is a sensitive method to confirm the clinical diagnosis of APN, although a substantial number of infants appear to have normal scans. Early determination of the urine NAG/creatinine and albumin/ creatinine quotients may further improve the diagnostics in the infant.
authors.affiliation: Department of Paediatrics, St. Göran's Hospital, Stockholm, Sweden.
authors.forename: T
authors.initials: T
authors.lastname: Linné
authors.forename: O
authors.initials: O
authors.lastname: Fituri
authors.forename: R
authors.initials: R
authors.lastname: Escobar-Billing
authors.forename: A
authors.initials: A
authors.lastname: Karlsson
authors.forename: I
authors.initials: I
authors.lastname: Wikstad
authors.forename: A
authors.initials: A
authors.lastname: Aperia
authors.forename: K
authors.initials: K
authors.lastname: Tullus
mesh_terms: D000118:Acetylglucosaminidase / Q000652:urine; D000208:Acute Disease; D000419:Albuminuria / Q000652:urine; D002648:Child; D002675:Child, Preschool; D003404:Creatinine / Q000652:urine; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D015609:Organotechnetium Compounds; D010783:Photometry; D011704:Pyelonephritis / Q000000981:diagnostic imaging* / Q000378:metabolism; D011877:Radionuclide Imaging; D004113:Succimer; D019783:Technetium Tc 99m Dimercaptosuccinic Acid; D014463:Ultrasonography
chemical_list: D015609:Organotechnetium Compounds; D019783:Technetium Tc 99m Dimercaptosuccinic Acid; D003404:Creatinine; D004113:Succimer; D000118:Acetylglucosaminidase