<prompt> Non-visualisation of kidney in excretory urogram is seen inDuplicationRenal vein thrombosisHydronephrosisHypoplasia  <response>: B i.e. Renal vein thrombosis - Nonvisualization of kidney or absence of nephrogram occurs in complete renal ischemia secondary to occlusion of main renal aery, global absence or focal renal infarctionischemia secondary to focal aerial occlusion or renal vein thrombosisQ or space occupying lesions segmental absence. - Persistent dense nephrogram both increasingly or immediate is seen in systemic hypotension, severe dehydrationQ, renal aery stenosis, renal vein thrombosis, tubular obstruction damage and urinary tract obstruction eg ureteral obstructionQ but not in systemic hypeension. Although hydronephrosis usually 1t scallopedshell i.e. non smooth rim nephrogramQ. 