Figure 15a. Emphysematous pyelonephritis in a 60-year-old diabetic man with several days’ history of nausea and general malaise. (a) Longitudinal US image of the left kidney demonstrates normal findings. (b) Longitudinal US image of the right kidney shows foci of high-amplitude echoes (long arrow) with associated posterior dirty shadowing (short arrow). (c) Corresponding contrast-enhanced CT scan obtained during the late excretory phase shows multiple parenchymal gas collections (arrows). Earlier-phase images (not shown) demonstrated decreased perfusion and excretion relative to the normal left kidney.