[Acute renal vein thrombosis in children. Early detection with duplex and color-coded Doppler ultrasound].

Two children with clinically suspected renal vein thrombosis were evaluated by duplex Doppler sonography and colour flow imaging. Both cases presented unspecific findings with an enlarged kidney and loss of cortico-medullary delineation on gray-scale ultrasound, but an unusual flow pattern with retrograde plateau-like frequency shifts during diastole. No venous signal could be obtained. By colour flow imaging only the main renal artery and its proximal branches could be visualised with a reverberating oscillation of blood flow. In addition, partial thrombosis of inferior vena cava in one patient and iliac vein thrombosis in the other could be demonstrated. Clinical improvement during fibrinolytic therapy in one case and nephrectomy in the other case confirmed the diagnosis.