Sequential sonographic features in neonatal renal vein thrombosis.

Abstract

Renal vein thrombosis in newborns is a rare but serious and acute disease. Clinical representations of RVT can vary from discrete symptoms to life-threatening conditions. Therefore imaging, and in particular sonography, plays an important role in the diagnosis of RVT in neonates. Gray-scale, color and spectral/power Doppler ultrasound are all used in the diagnosis of RVT. We present retrospective sequential ultrasonic imaging of three patients (two term and one preterm infant) with findings characteristic of RVT. Initial ultrasound diagnostic features include: renal enlargement, echogenic medullary streaks, lack of the flow pattern characteristic of arcuate vessels and subsequently loss of corticomedullary differentiation, reduced echogenicity around pyramids and echogenic band at the extreme apex of the pyramid. Higher resistance index or less pulsatile venous flow on the affected kidney are helpful Doppler signs. Knowledge and identification of specific features of each phase of the evolution of RTV seems essential to prompt diagnosis. We would like to highlight the evolution of specific sonographic features in each subsequent phase of RVT.