A. Cvitković Kuzmić, B. Brkljačić

Color duplex Doppler ultrasonography has been extensively used in the assessment of various kidney diseases in adults and children. It enables evaluation of intrarenal flow, of blood vessels distribution and, and noninvasive evaluation of renal vascular resistance by measuring renal resistance index. In pediatric nephrology Doppler was first used to evaluate vascular alterations in transplanted kidneys. In native kidneys Doppler is used for the diagnosis and follow-up of hemolytic-uraemic syndrome, renal artery stenosis and renal vein thrombosis, for differentiation between obstructive and nonobstructive pelvicalicectasis, and for the evaluation of renal vascular resistance in various renal parenchymal diseases. It is also used for the detection of biopsy complications - A-V fistulas and pseudoaneurismas, and for the evaluation of the perfusion of kidney neoplasms. Power Doppler enables better visualisation of the small vessels with slow and is indicated for the detection of hyperemia in the areas of acute inflammation, for detection of neopastic vessels, and for the detection of areas of decreased flow due to ischemia and infarction. Doppler can be used to visualize ureteric jets, representing inflow of urine into the bladder. Doppler analyses of ureteric jets can be used in evaluation of normal ureteric physiology, in the detection of unilateral ureteric obstruction, and vesicoureteric reflux in children.