Marked bilateral global persistent CT nephrogram 48 h after percutaneous coronary intervention with contrast-induced nephropathy requiring transient hemodialysis with severe cardiac dysfunction.

An iodinated contrast medium (CM) is generally excreted into the urinary tract within 3 min after administration. However, some cases present a persistent kidney nephrogram several hours after administration of CM. This phenomenon seems to be associated with the development and acceleration of contrast-induced nephropathy (CIN). A 74-year-old woman with chronic kidney disease and a very low ejection fraction (EF) (11%) was admitted to Sapporo Medical University Hospital because of heart failure. Coronary angiography revealed occlusion of the left anterior descending artery (LAD) on day 21 of admission. Percutaneous coronary intervention (PCI) to the LAD using 218 ml of iohexol was performed with a preventive measure for CIN by saline infusion on day 28. After PCI, she developed CIN requiring hemodialysis. Non-contrast computed tomography 48 h after PCI showed a marked bilateral persistent nephrogram with a cortical attenuation value of 168 HU. Vicarious excretion of CM was noted in the small bowel and colon. Her kidney function gradually recovered and hemodialysis was discontinued after ten sessions on day 43. The findings from this case suggest that a patient with a very low EF is at a high risk for CIN through persistent retention of the CM in the kidney cortex.

Acute interstitial nephritis manifesting as a persistent nephogram.

We report a case of a 61-year-old woman who presented to the emergency department with high inflammatory parameters and acute renal failure. Marked enlarged kidneys with persistent nephrogram were found on contrast-enhanced computed tomography . Renal biopsy showed acute interstitial nephritis. Acute interstitial nephritis must be included in the differential diagnosis in patients presenting with a persistent nephrogram.

Acute Renal Failure with Severe Loin Pain and Patchy Renal Vasoconstriction in a Patient without Hypouricemia, Provoked by Epileptic Seizure.

A 26-year-old Japanese man without hypouricemia and with 3 previous episodes of seizures concurrent with acute kidney injury (AKI) was admitted due to an epileptic seizure, lower back pain and AKI. His creatinine kinase levels were slightly elevated. Patchy renal ischemia on contrast-enhanced computed tomography and persistent residual contrast medium was observed, consistent with acute renal failure with severe loin pain and patchy renal ischemia after anaerobic exercise (ALPE). Diffusion-weighted imaging (DWI) demonstrated signal changes in the corresponding area. ALPE should be considered a cause of AKI following seizures. We recommend DWI as an alternative diagnostic modality.