Contrast enhancement in abdominal CT: bolus vs. infusion

Abstract
The accuracy of in vivo iodine estimations by CT in the aortic blood was determined in the dog. Iodine wash-out curves of five patients each receiving either a bolus of 100 ml diatrizoate 60% or a 10 min infusion of 300 ml diatrizoate 30% and 138 nonenhanced abdominal CT scans with various lesions in 104 patients were analyzed. This investigation suggests: (1) In vivo estimations of iodine concentrations are subject to considerable variation. (2) Iodine accumulation and wash-out for a given contrast administration mode are similar in liver, spleen, and pancreas with tissue iodine concentrations always below blood iodine concentrations, while a significant iodine concentration above iodine blood levels is found in the renal parenchyma. (3) If contrast enhancement is analyzed separately for bolus effect (arteriovenous iodine difference [AVID] greater than 30 H), nonequilibrium phase (AVID 10-30 H) and equilibrium phase (AVID less than 10 H), a good correlation between aortic blood and tissue iodine concentr...