Dynamic contrast enhancement of the upper abdomen: effect of contrast medium and body weight.

Contrast enhancement (CE) of the aorta, liver, and spleen was studied in dynamic body computed tomography (CT) in 71 patients. Four contrast media (CM) (diatrizoate, ioxithalamate, ioxaglate, iopamidol) were injected intravenously in equal bolus doses of 18.5 g iodine. Iopamidol produced the highest average peak and 2-minute aortic CE, significantly different from ioxithalamate (P less than 0.001), diatrizoate (P less than 0.01), and ioxaglate (P less than 0.0125) at peak levels. Two-minute CE values of the aorta were highest with iopamidol as were peak and 2 minute CE of the liver and spleen. A linear, inverse relationship between body weight and CE was present both at peak CE and after 2 minutes in all tissues. The nonionic CM appear to have best dose efficiency in the vascular phase of dynamic CT. These results are also applicable to digital angiography. Differences in the CE of parenchymal organs with different CM are so small that they are unlikely to have clinical significance.