title: Tc-99m DMSA renal scan in first-time versus recurrent urinary tract infection-yield and patterns of abnormalities.
abstract: OBJECTIVE
  To determine the yield and patterns of abnormalities noted by Tc-99m DMSA renal imaging in cases of first-time versus recurrent urinary tract infections (UTIs) in children.
  
  
  METHODS
  We reviewed 101 Tc-99m DMSA studies performed for 52 first-time and 49 recurrent UTIs in 99 children during a period of 1 year. The average age of the patients was 4.4 years, and the female:male ratio was 7:1. Static images of the kidneys were acquired 2 hours after injection of Tc-99m DMSA in anterior, posterior, and right and left posterior oblique views. SPECT was performed in 9% of the cases. The studies were scored as normal or abnormal.
  
  
  RESULTS
  The yield of abnormal scans in first-time UTIs was 22 (42%) and in recurrent UTI 27 (55%). Three categories of abnormalities were noted: 1) renal cortical defects (55% of the abnormal scans in first-time UTIs and 59% of the abnormal scans in recurrent UTIs; P = 0.40); 2) dilated pelvicalyceal system (27% of the abnormal studies in first-time UTIs and 63% of the abnormal studies in recurrent UTIs; P < 0.01); and 3) renal swelling showing disproportionate function with size (41% of the abnormal scans in first-time UTIs and 22% of the abnormal scans in recurrent UTIs; P = 0.21).
  
  
  CONCLUSIONS
  The high yield of renal abnormalities by Tc-99m DMSA scanning emphasizes the importance of testing all cases of UTI, including patients with a first-time infection. Documentation of the pattern of abnormalities may help in planning for subsequent management of UTIs in these patients.
authors.affiliation: Department of Nuclear Medicine, Kuwait University and Mubarak Hospital, Ministry of Public Health, Safat. loutfi@hsc.kuniv.edu.kw
authors.forename: I
authors.initials: I
authors.lastname: Loutfi
authors.forename: K
authors.initials: K
authors.lastname: Al-Zaabi
authors.forename: A H
authors.initials: AH
authors.lastname: Elgazzar
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D004108:Dilatation, Pathologic / Q000000981:diagnostic imaging; D004487:Edema / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007668:Kidney / Q000000981:diagnostic imaging*; D007670:Kidney Calices / Q000000981:diagnostic imaging; D007672:Kidney Cortex / Q000000981:diagnostic imaging; D007682:Kidney Pelvis / Q000000981:diagnostic imaging; D008297:Male; D010347:Patient Care Planning; D011379:Prognosis; D019275:Radiopharmaceuticals; D012008:Recurrence; D012189:Retrospective Studies; D019783:Technetium Tc 99m Dimercaptosuccinic Acid; D015899:Tomography, Emission-Computed, Single-Photon; D014552:Urinary Tract Infections / Q000000981:diagnostic imaging*
chemical_list: D019275:Radiopharmaceuticals; D019783:Technetium Tc 99m Dimercaptosuccinic Acid