Value of imaging studies after a first febrile urinary tract infection in young children: data from Italian renal infection study 1.
OBJECTIVE
We examined the diagnostic accuracy of routine imaging studies (ultrasonography and micturating cystography) for predicting long-term parenchymal renal damage after a first febrile urinary tract infection.


METHODS
This study addressed the secondary objective of a prospective trial evaluating different antibiotic regimens for the treatment of acute pyelonephritis. Data for 300 children < or =2 years of age, with normal prenatal ultrasound results, who completed the diagnostic follow-up evaluation (ultrasonography and technetium-99m-dimercaptosuccinic acid scanning within 10 days, cystography within 2 months, and repeat technetium-99m-dimercaptosuccinic acid scanning at 12 months to detect scarring) were analyzed. Outcome measures were sensitivity, specificity, and negative and positive predictive values for ultrasonography and cystography in predicting parenchymal renal damage on the 12-month technetium-99m-dimercaptosuccinic acid scans.


RESULTS
The kidneys and urinary tracts were mostly normal. The acute technetium-99m-dimercaptosuccinic acid scans showed pyelonephritis in 54% of cases. Renal scarring developed in 15% of cases. The ultrasonographic and cystographic findings were poor predictors of long-term damage, showing minor sonographic abnormalities for 12 and reflux for 23 of the 45 children who subsequently developed scarring.


CONCLUSIONS
The benefit of performing ultrasonography and scintigraphy in the acute phase or cystourethrography is minimal. Our findings support (1) technetium-99m-dimercaptosuccinic acid scintigraphy 6 months after infection to detect scarring that may be related to long-term hypertension, proteinuria, and renal function impairment (although the degree of scarring was generally minor and did not impair renal function) and (2) continued surveillance to identify recurrent urinary tract infections that may warrant further investigation.
Montini
Giovanni
G
Departments of Pediatric Nephrology, University of Padua, Padua, Italy. montini@pediatria.unipd.it
Zucchetta
Pietro
P
Tomasi
Lisanna
L
Talenti
Enrico
E
Rigamonti
Waifro
W
Picco
Giorgio
G
Ballan
Alberto
A
Zucchini
Andrea
A
Serra
Laura
L
Canella
Vanna
V
Gheno
Marta
M
Venturoli
Andrea
A
Ranieri
Marco
M
Caddia
Valeria
V
Carasi
Carla
C
Dall'amico
Roberto
R
Hewitt
Ian
I
D002675:Child, Preschool; D005260:Female; D005334:Fever / Q000209:etiology; D006801:Humans; D007223:Infant; D007558:Italy; D007674:Kidney Diseases / Q000150:complications / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000209:etiology; D008297:Male; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011859:Radiography; D011877:Radionuclide Imaging; D015203:Reproducibility of Results; D014463:Ultrasonography; D014552:Urinary Tract Infections / Q000150:complications / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000628:therapy