ABSTRACT
Introduction The previous chapters have shown the feasibility of the IVUS technique for the diagnosis of aortic diseases. The IVUS technique described, with an ultrasound (US) catheter placed intra-aortally, provides a 360°, panoramic cross-sectional image of the aortic inner wall via a 360° fast rotation of the US element at the tip of the catheter. Similar to intra coronary imaging with cross-sections of coronary vessels, the intra-aortal two-dimensional images show the morphologic changes in the respective aortic cross-sections. However, to obtain information about the extension of any aortic wall disease along the aorta, the IVUS catheter has to be pulled back slowly with on-line image registration. During that procedure the two-dimensional cross-sectional images change, corresponding to the catheter position, and the observer mentally composes the single images to form a three-dimensional impression. The interpretation of that kind of 3-dimensional impression is strongly observer-dependent, and therefore subjective, and not available for documentation.
