boy of six month having left kidney hydronephrosis from birth ec scan done on 4 months and 6 months scan at 4 months split function left 42.32 right 57.68 scan at 6 months split function left 44 right 56 ultrasound at 4 months left kidney 6.4*2.5, cortical thickness 3 mm pole calyses 7.9,7.7,6mm. AP diameter 18 mm ultrasound at 6 months left kidney 6.4 cortical thickness 4.5, 4.8,4.7mm APD pelvis 24.5