Contrast enhancement of the liver and blood. Nonionic versus ionic contrast media in the pig.

The contrast enhancement of low-osmolality (iohexol) and high-osmolality (diatrizoate) contrast media was compared in 18 pigs following intravenous bolus administration. Liver and blood attenuation and blood sample iodine concentration were measured during the first 3 minutes after injection. Iohexol produced a significantly higher contrast enhancement in the blood during the period from 0.5 to 3 minutes after injection. Diatrizoate produced a significantly higher contrast enhancement in the liver during the period from 9 to 30 minutes after injection. The greater contrast enhancement of iohexol during the acute phase should be advantageous in dynamic CT.