[Color coded ultrasound--quantification of perfusion in a perfusion model]

This experimental study demonstrates the quantification of perfusion in a phantom-simulating tissue using a computer-assisted interpretation. The parameters flow volumin, velocity (defined by pulse-repetition-frequency-PRF), and the time of adding up peaks were varied. The detected color-coded pixels determine the flow area as a percentage of the ground area and the frequency with the highest pixel density. The width is the area between the highest and lowest detected frequencies. The flow area correlates with the perfusion rate (r > or = 0.97). To detect low perfusions, a slow velocity and extended Peak Hold-function are necessary. Peaks with a high frequency superpose those with lower frequencies, so that these signals are not available for the interpretation. To determine the width or the frequency with highest pixel density a short Peak Hold-function must be chosen. When changing the velocity, these quantities are also changed, so that standards are necessary. This study shows a correlation between a defined perfusion in a phantom-simulating tissue and the flow area. It suggests a possibility to quantify flow in different organs. One aim would be to determine abnormal vascularisation, for example, in tumours of the liver or breast.