ACUTE CHILDHOOD PYELONEPHRITIS - PREDICTIVE VALUE OF POSITIVE SONOGRAPHIC FINDINGS IN REGARD TO LATER PARENCHYMAL SCARRING

Rationale and Objectives. The authors evaluated the importance of posi tive sonographic findings in acute childhood pyelonephritis. Materials and Methods, A total of 290 children (91 boys, 199 girls, aged 4 days to 15 years [median, 394 days]) with clinically suspected acute pyelo nephritis underwent initial renal gray-scale ultrasound (US) and dimer captosuccinate scintigraphic examination within 3 days of onset. A tot al of 173 patients underwent color or energy US examination. One hundr ed fifteen children with normal scintigraphic or pathologic findings ( other than acute pyelonephritis) were excluded from further study; 170 patients with abnormal scintigraphic findings underwent follow-up sci ntigraphic scanning 60-90 days later. Results. When pathologic structu res other than acute pyelonephritis were not considered, the diagnosti c value of gray-scale US was poor, with a sensitivity of 45.5%, a spec ificity of 86.6%, a positive predictive value of 88.8%, and a negative predictive value of only 40.6%. In regard to future renal scarring, g ray-scale US had a positive predictive value of 67.7%, a negative pred ictive value of 40%, and a likelihood ratio of 1.16. Abnormal Doppler findings helped predict future scarring with a positive predictive val ue of 85.7%, a negative predictive value of 37.2%, a very low sensitiv ity of 26.9%, a high specificity of 90.6%, and a likelihood ratio of 2 .87. Conclusion. Positive US Doppler findings in children with clinica lly suspected acute pyelonephritis indicate the need for immediate tre atment. A positive initial gray-scale US examination does not predict future renal scarring, but a positive Doppler examination indicates a high probability of scarring. Negative gay-scale or Doppler US does no t exclude a diagnosis of acute pyelonephritis and it cannot predict an absence of future scarring.