Left renal enlargement, with patchy or striated nephrogram and cortical wedge-shaped areas of decreased density. There is a loss of normal corticomedullary differentiation with multiple peripheral and cortical abscesses. There is a thickening of the walls of the renal pelvis, calyces and proximal ureter with abnormal enhancement.
Excretory phase demonstrates streaky linear bands of alternating high and low attenuation.