An 81-year-old man with chronic kidney disease, hypertension, and aortic stenosis was admitted with a fever and nausea. Computed tomography (CT) of the abdomen with intravenous administration of iodixnanol was performed on the day of admission at another hospital ([Picture 1](#g001){ref-type="fig"}). One day later, unenhanced CT of the abdomen was repeated, showing a striking enhancement of the renal parenchyma of both kidneys ([Picture 2a](#g002){ref-type="fig"} and [b](#g003){ref-type="fig"}). Seven days later, unenhanced CT was performed again for a persistent fever and newly developed abdominal pain. No residual renal cortical attenuation was noted in either kidney. Although the patient received hydration therapy for the prevention of contrast-induced nephropathy, his serum creatinine rose to 3.3 mg/dL from his baseline of 1.6 mg/dL one day after the administration of the contrast media. The prolonged renal cortical retention of contrast media is called persistent nephrogram. While details regarding the mechanism of persistent nephrogram are unclear, some have hypothesized that it represents a tubular obstruction or a generalized shutoff of glomerular filtration, as a consequence of altered glomerular hemodynamics ([@B1]).

![](1349-7235-55-3687-g001){#g001}

![](1349-7235-55-3687-g002){#g002}

![](1349-7235-55-3687-g003){#g003}

The authors state that they have no Conflict of Interest (COI).
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[^1]: Correspondence to Dr.　Naohiko Imai, <imaix006@umn.edu>
