In the study group of 65 children and adolescents with cadaveric renal transplant the authors investigated the role of sonography in differentiating various kidney transplant diseases. From 628 duplex Doppler examinations performed in normal functioning grafts they calculated normal resistive index, RI = 0.664 ± 0.004. 99.5% of all children had RI < 0.8. The authors assessed changes in renal morphology, length, volume, RI and diastolic velocity during acute rejection (AR), acute tubular necrosis (ATN), cyclosporine nephrotoxicity (CsTox), pyelonephritis (PN) and chronic rejection (CR). They found significant changes of renal lenght, RI and diastolic velocity predomi- nantly in AR (p < 0.0001). 18% of patients with AR and 20% patients with ATN had RI > 0.9, no patient with CsTox, PN or CR had a RI greater than 0.9. 37% of acute rejection patients, 40% of patients with ATN and 17% of patients with CsTox had RI in the normal range (0.6 - 0.69). The sensitivity of sonography in diagnosing AR was 75 %, the specificity was 86%. Sonography cannot reliably replace biopsy that allows early identification of allograft dysfunction cause and enables specific treatment.

        Key words: ultrasonography - Doppler - kidney transplantation - children