Renal power Doppler ultrasound does not predict renal scarring after urinary tract infection.
OBJECTIVE
Young children may develop renal scarring following a urinary tract infection (UTI) especially after pyelonephritis which is difficult to diagnose. Permanent renal scars are diagnosed by dimercapto-succinic acid (DMSA) scan several months later. To decrease unnecessary exposure to radiation, we investigate the role of renal power Doppler (RPD) in predicting those who may not require a late DMSA scan.


METHODS
Children under four years of age with a first UTI underwent an RPD study soon after diagnosis, and a DMSA scintigraphy six months later. The predictive values of the early RPD to detect DMSA renal scarring were calculated.


RESULTS
Twenty three children (median age 30 months) were enrolled: 13 had a febrile presentation, two with bacteraemia. Permanent scarring occurred in three children (13%). In the 46 kidney units studied, initial RPD was abnormal in two and late DMSA abnormal in three units. Overall concordance between RPD and DMSA was 93.5%. The sensitivity of RPD for renal scar as per DMSA was 33.3%, specificity 97.7%; positive predictive value 50% and a negative predictive value of 95.4%.


CONCLUSIONS
RPD offered no advantage over ultrasound to predict renal scarring and cannot be recommended to predict renal scarring following UTI.
Narchi
H
H
Paediatric Department, Sandwell General Hospital, West Bromwich, B71 4HJ, United Kingdom. hassibnarchi@hotmail.com
Donovan
R
R
D002675:Child, Preschool; D002921:Cicatrix / Q000000981:diagnostic imaging* / Q000209:etiology; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007668:Kidney / Q000000981:diagnostic imaging*; D008297:Male; D011237:Predictive Value of Tests; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D019783:Technetium Tc 99m Dimercaptosuccinic Acid; D018608:Ultrasonography, Doppler; D014552:Urinary Tract Infections / Q000150:complications*
D019275:Radiopharmaceuticals; D019783:Technetium Tc 99m Dimercaptosuccinic Acid