Session: P1E - BEAMFORMING I

the motion of the artery over time. Because of poor image quality and high geometric variability of AAA, the development of a dedicated segmentation tool was required. It provides a semiautomatic detection of the aortic walls and is adapted to image variability. The motion of the walls over time is deduced from the TDI velocity measurements at the location of the artery walls. Due to the use of a curved array, the variations of the Doppler angle require TDI velocities correction. Measurements of diameters, dilations, distensibility and pulsatility are derived. Preliminary clinical tests were performed to assess the potential of the method. Areas of interest are the follow up of AAAs, before and after surgical treatment. For AAAs treated with endoprosthesis, the main interest lies in the detection of leaks, which are potentially dangerous, and not always visible with conventional Doppler imaging. Reproducibility of the measurements was also evaluated and will be detailed in the presentation. Sequences of 24 witnesses, 23 patients with AAA and 20 patients with AAA treated with endoprosthesis were acquired. For witnesses, patterns of dilations are spatially homogeneous. On the contrary, AAAs exhibit inhomogeneous dilation patterns, with maximum amplitude at the maximum diameter. Pulsatility of the AAAs could be observed clearly in dynamic viewing of the dilations. The results for endoprosthesis show that the surgical treatment was able to reduce the AAA pulsatility. The dynamic behavior of some treated AAAs revealed leaks of endoprostheses.