| One of the most common cardiovascular diseases is coronary atherosclerosis, the build-up of plaque on artery walls. Intravascular ultrasound (IVUS) produces unique echographic images showing artery cross-sections that clearly reveal the lumen, walls and plaque, providing information about the nature of atherosclerosis lesions and plaque shape and size. However, the 3D geometry of the artery stay unknown and the different regions of interest are difficult to determine in the IVUS images.;Given that an IVUS exam results in several hundred of images, which are often of poor quality due to speckle noise or calcification of the wall leading to the appearance of shadow in the images, the IVUS images are hard to visually analyze and it is useful to develop automatic analysis tools for this type of images. The second part of this thesis present a new IVUS segmentation method based on helical active contour approach.;These works promise a more accurate and efficient use of the intravascular echography.;Keywords: intravascular imaging(IVUS), single-plane angiography, 3D reconstruction, 2D/3D tracking, 3D segmentation;Several 3D reconstruction methods of arteries required that we combine IVUS and two angiogram planes, a radiography of blood vessels, in order to use stereography principles. Unfortunately, these methods induce high costs, complicate the image acquisition process, are not available in all medical centers and lead to more radiations to the patient. To simplify and reduce the cost associated to biplane angiography procedure, we have elaborated an algorithm to recover the transducer 3D trajectory with a single view X-ray image sequence, presented in the first part of this thesis. |
