Persistent nephrogram after administration of an isoosmolar contrast medium.

Recently, we performed a contrast-enhanced thoracic 16-channel multi-slice computed tomography (CT) with intravenous (i.v.) administration of iodixanol [Visipaque, dose 0.5 g I/kg body weight (bw)] in a 73-year old patient, suffering from multiple myeloma and chronic renal failure (calculated creatinine clearance of 23ml/min). Three days later, an unenhanced CT of the upper abdomen was performed, showing a striking enhancement of the renal parenchyma of both kidneys [mean, 142 hounsfield units (HU)] (Figure 1). No contrast excretion within the collection system was noted. Eight days later there was still residual renal cortical attenuation of both kidneys (67HU). Unenhanced CT 17 days after the first examination revealed normal findings of both kidneys with complete vanishing of the parenchymal abnormality. The baseline serum creatinine was 2.3mg/dl (202 mmol/l) and rose to 2.6mg/dl (235 mmol/l) 4 days after the administration of the contrast media. Comment