The presence of vesicoureteric reflux does not identify a population at risk for renal scarring following a first urinary tract infection.
BACKGROUND
Childhood urinary tract infection (UTI) with or without vesicoureteric reflux (VUR) may predispose to renal scarring. There is no clear consensus in the literature regarding imaging following UTI in infancy.


OBJECTIVE
To define the role of cystography following a first UTI in children aged under 1 year, when urinary tract ultrasonography (US) is normal.


METHODS
Retrospective data collection of 108 children (216 renal units) aged under 1 year at the time of a bacteriologically proven UTI. All had a normal US and underwent both catheter cystogram and DMSA test. Sensitivity, specificity, likelihood ratios positive and negative, and diagnostic odds ratio were calculated for VUR on cystography versus scarring on DMSA.


RESULTS
VUR was shown in 25 (11.6%) renal units. Scarring on DMSA was seen in 8 (3.7 %) kidneys. Only 16% of kidneys with VUR had associated scarring; 50% of scarred kidneys were not associated with VUR. The likelihood ratio positive was 4.95 (95% CI 2.22 to 11.05) and the likelihood ratio negative was 0.56 (95% CI 0.28 to 1.11). The diagnostic odds ratio was 8.9, suggesting that cystography provided little additional information.


CONCLUSIONS
Since only 16% of children with VUR had an abnormal kidney, the presence of VUR does not identify a susceptible population with an abnormal kidney on DMSA. In the context of a normal ultrasound examination, cystography contributes little to the management of children under the age of 1 year with a UTI. In this context, a normal DMSA study reinforces the redundancy of cystography.
Moorthy
I
I
Department of Clinical Radiology, Great Ormond Street Hospital for Children, London, UK. jimandima@aol.com
Easty
M
M
McHugh
K
K
Ridout
D
D
Biassoni
L
L
Gordon
I
I
D002921:Cicatrix / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000209:etiology*; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007674:Kidney Diseases / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000209:etiology*; D008297:Male; D011859:Radiography; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D019783:Technetium Tc 99m Dimercaptosuccinic Acid; D014552:Urinary Tract Infections / Q000150:complications* / Q000175:diagnosis / Q000000981:diagnostic imaging; D014718:Vesico-Ureteral Reflux / Q000150:complications* / Q000175:diagnosis
D019275:Radiopharmaceuticals; D019783:Technetium Tc 99m Dimercaptosuccinic Acid