Low microbubble concentrations signal enhancement varying echograph electrical power

Abstract

This work has the aim to assess the influence of the Echograph Electrical Power (EEP) on the ultrasound contrast agent (UCA) behavior and the effect of UCA concentration on backscatter enhancement. In several studies there has been the tendency to use high UCA concentrations and high EEP, but this could limit the safety of the microbubbles. Here we show an investigation able to determine the effect on the backscatter intensity varying EEP and UCA concentrations. A new phospolipidic UCA and the last technological innovations in the field of signal processing and radiofrequency (RF) spectrum analysis were used in this study. Eighteen different saline-diluted UCA solutions were pumped into the vessel cavities of a new tissue-mimicking phantom and insonified at constant frequency varying EEP. The acquired RF data were digitally stored and off-line processed by algorithms ad hoc developed by means of a new software research package. The obtained results show that UCA backscatter can be considered independent by UCA concentration at high dilutions, while it is clearly influenced by incident acoustic pressure values in the whole tested dilution range.