Improved modelling of ultrasound contrast agent diminution for blood perfusion analysis.

Ultrasound contrast imaging is increasingly used to analyze blood perfusion in cases of ischemic or cancerous diseases. Among other imaging methods, the diminution harmonic imaging (DHI), which modells the diminution of contrast agent due to ultrasound pulses, is the most promising because of its speed. However, the current imaging quality of DHI is insufficient for reliable diagnoses. In this paper, we extend the mathematical DHI model to include the part of the intensity signal which is due to tissue reflections and other effects not based on the contrast agent and its concentration in the blood. We show in a phantom experiment with available perfusion ground truth the vast improvements in accuracy of the new model. Our findings also strongly support the theory of a linear relationship between the perfusion speed and the determined perfusion coefficient, which is a large step towards quantitative perfusion measurements.