IMPROVED ULTRASOUND DETECTION OF RENAL SCARRING IN CHILDREN FOLLOWINGURINARY-TRACT INFECTION

A system for defining renal scarring on ultrasound is proposed and com pared with DMSA scintigraphy, Renal scarring was assessed with ultraso und in children following urinary tract infection (UTI) using the foll owing criteria: (1) proximity of sinus echoes to cortical surface; (2) loss of pyramids; (3) irregularity of outline; (4) loss of definition of capsular echo; and (5) calyceal dilatation, Three hundred and thir ty-nine consecutive ultrasound scans (US) and DMSA scintigrams, compri sing 648 kidneys, were performed and reported blindly and the results were compared. Using DMSA scintigraphy as the gold standard, ultrasoun d had a positive predictive value of 93 % and a negative predictive va lue of 95 %. Ultrasound disagreed with DMSA scintigraphy in 5.2 % of k idneys. On review of the cases of disagreement where arbitration was p ossible by comparison with other imaging, ultrasound was incorrect in 10 kidneys and DMSA was incorrect in 13, We conclude that the sensitiv ity in the ultrasound detection of renal scarring can be greatly impro ved using this method. If no scars were detected at ultrasound an alte rnative explanation for an abnormal DMSA scintigram should be sought.