Persistence of gadolinium in CSF: a diagnostic pitfall in patients with end-stage renal disease.

Two dialysis-dependent patients with end-stage renal disease underwent brain and spine MR imaging a few days after having undergone gadolinium-enhanced imaging studies. Increased signal intensity in the subarachnoid space on T1-weighted and fluid-attenuated inversion recovery images was noted. Excretion of gadolinium into the CSF was proven in one case by mass spectrometry. Dialysis-dependent patients with end-stage renal disease and neurologic abnormalities often undergo contrast-enhanced MR imaging. Recognition that these patients may show increased signal intensity in the subarachnoid space because of gadolinium excretion into CSF may prevent diagnostic errors.