We demonstrate the feasibility of intravascular ultrasound (IVUS) chirp imaging as well as chirp reversal ultrasound contrast imaging at intravascular ultrasound frequency. Chirp excitations were emitted with a 34 MHz single crystal intravascular transducer and compared to conventional Gaussian-shaped pulses of equal acoustic pressure. The signal to noise ratio of the chirp images was increased by up to 9 dB relative to the conventional images. Imaging of contrast microbubbles was implemented by chirp reversal, achieving a contrast to tissue ratio of 12 dB. The method shows potential for intravascular imaging of structures in and beyond coronary atherosclerotic plaques including vasa vasorum.

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This paper proposes a new approach - set up within the REALISEGRID research project - for speeding up approval procedures for building transmission infrastructure. The experiences of Transmission System Operators from Netherlands, Italy, France, Austria and Germany are studied in order to generalize and pinpoint the main weaknesses and strengths of current approval procedures. Recommendations concerning how to reduce the time needed for approval procedures are made. The problem of consensus improvement is also analysed. Suggestions for better structuring of the decision process in transmission planning, with high involvement of stakeholders, are made. A systemic approach for speeding up authorization procedures is proposed by combining the country survey and the consensus improvement findings. Actions are defined on different time horizons.@en