Imaging strategy for infants with urinary tract infection: a new algorithm.
OBJECTIVE
We analyzed clinical data for prediction of permanent renal damage in infants with first time urinary tract infection.


METHODS
This population based, prospective, 3-year study included 161 male and 129 female consecutive infants with first time urinary tract infection. Ultrasonography and dimercapto-succinic acid scintigraphy were performed as acute investigations and voiding cystourethrography within 2 months. Late scintigraphy was performed after 1 year in infants with abnormality on the first dimercapto-succinic acid scan or recurrent febrile urinary tract infections. End point was renal damage on the late scan.


RESULTS
A total of 270 patients had end point data available, of whom 70 had renal damage and 200 did not. Final kidney status was associated with C-reactive protein, serum creatinine, temperature, leukocyturia, non-Escherichia coli bacteria, anteroposterior diameter on ultrasound and recurrent febrile urinary tract infections. In stepwise multiple regression analysis C-reactive protein, creatinine, leukocyturia, anteroposterior diameter and non-E.coli bacteria were independent predictors of permanent renal damage. C-reactive protein 70 mg/l or greater combined with anteroposterior diameter 10 mm or greater had sensitivity of 87% and specificity of 59% for renal damage. An algorithm for imaging of infants with first time urinary tract infection based on these results would have eliminated 126 acute dimercapto-succinic acid scans compared to our study protocol, while missing 9 patients with permanent renal damage.


CONCLUSIONS
C-reactive protein can be used as a predictor of permanent renal damage in infants with urinary tract infection and together with anteroposterior diameter serves as a basis for an imaging algorithm.
Department of Pediatrics, Queen Silvia Children's Hospital, Sahlgrenska Academy, University of Gothenburg, Göteborg, Sweden. iulian.preda@vgregion.se
Iulian
I
Preda
Ulf
U
Jodal
Rune
R
Sixt
Eira
E
Stokland
Sverker
S
Hansson
D000465:Algorithms; D005260:Female; D006801:Humans; D007223:Infant; D007674:Kidney Diseases / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000209:etiology*; D008297:Male; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D019783:Technetium Tc 99m Dimercaptosuccinic Acid; D014463:Ultrasonography; D014552:Urinary Tract Infections / Q000150:complications*
D019275:Radiopharmaceuticals; D019783:Technetium Tc 99m Dimercaptosuccinic Acid