Solution: A "striated nephrogram" is a finding that can be seen in both the nephrographic and the excretory phase, although it is more commonly thought of in the excretory phase. This is a delayed CT (reason for the delay is unclear, it was done at an outside facility) that beautifully shows the stasis of contrast material in dilated tubules within a background of edematous renal parenchyma. The stasis is likely due to obstruction of the tubule by inflammatory cells and/or debris. It does have a differential including obstruction, pyelonephritis, contusion, renal vein thrombosis, hypotension, ARPDK, and Medullary sponge kidney, but with this appearance and history, one would be most concerned about severe pyelonephritis. The US images show decreased flow within the renal parenchyma with hypoechogenicity within the parenchyma, typical of pyelonephritis. Urinalysis should confirm. Pyelonephritis tends to be secondary to gram negative organisms and in this case was secondary to E. coli.