Quantification of flow rates using harmonic grey scale imaging in an in-vitro-model

The capability of the dye dilution theory to measure perfusion using harmonic imaging was investigated. An in-vitro study using six doses of Levovist as the ultrasound contrast agent was conducted. Results showed that the area under the curve (AUC) and the peak increase increased only in the dose range between 0.1 and 1.0 ml. Further increase had no effect. However, increasing the flow rate decrease the AUC and the mean transit time. Thus, the dye dilution theory is not a useful theoretical model for the analysis of perfusion using harmonic imaging.