Bolusgeometrie und -dynamik nach intravenöser Kontrastmittelinjektion

Abstract

Studies of contrast bolus geometry and dynamics were carried out by means of a chronogram - a digital serial radiographic method. Four situations were considered - contrast volume, speed of injections, subsequent saline injections and rapidly repeated contrast boli. Peak values, maximum duration and half-life of the bolus and maximum contrast enhancement were recorded. The results have shown that a larger volume of contrast with reduced injection speed leads to a lengthening of the peak period. More rapid injection speed up to 8 ml/sec leads to a higher peak and increased contrast enhancement. Further increases of injection speed beyond 8 ml/sec does not further increase contrast enhancement. The subsequent injection of saline has no recognisable effect on bolus geometry or dynamics.

Optimizing liver contrast in helical liver CT: value of a real-time bolus-triggering technique

“…The dynamics and the geometry of an injected contrast bolus depend on contrast load and rate, as well as individual factors such as, for example, venous capacitance and cardiopulmonary function. Bolus geometry is characterized by the onset of contrast, its amplitude, and the duration of the bolus as described by Claussen et al [10,11]. Unfortunately, there is no direct correlation of bolus geometry with simple physiologic parameters such as heart rate, blood pressure, age, body surface, or weight [14].…”

“…It is dependent on contrast load and injection rate on the one hand. On the other hand, individual patient factors, such as cardiac output, peripheral resistance, and circulation time affect the geometry of the contrast bolus and may lead to considerable individual variability of peak enhancement and its time window [10,11]. Some investigators have tried small test boli for estimating circulation time and delay for digital subtraction angiography (DSA) and spiral CT [12±14]; however, this method is not without drawbacks.…”