Intrinsic particles in angiographic contrast media.

The five brands of water-soluble contrast media (sodium methylglucamine 60%) used most often for cerebral angiography in Europe were investigated for contamination with intrinsic nonviable particles. A Coulter counter was used to screen particles by size (5--10 mu, 10--30 mu, and greater than 30 mu), and scanning electron microscopy (SEM) combined with energy-dispersive x-ray analysis (EDAX) was used to verify the findings. Particles were found in the solutions, both from ampules and vials. The mean was 302 particles greater than 5 mu in 1 ml of contrast medium contained in ampules; a few particles measuring up to 500 mu were found. EDAX analysis revealed Ca, Cl, Co, Cr, Fe, I, K, Mn, Na, Si, and Zn. The author recommends that contrast media be passed through a filter with a pore size of 5 mu or less.