A more favourable intraarterial pattern of bolus dynamics can be expected in DSA on applying nonionic contrast media via the intravenous route, as can be concluded from the results of numerous experimental studies on the different effects of ionic and nonionic contrast media on cardiovascular function. However, bolus measurements of ionic and nonionic contrast media in intraindividual comparison of 28 patients via serio-CT did not yield any significant difference. The influences of various factors on measurement results--quantities of contrast media, time and method of measurement--are discussed as possible causes of this discrepancy.