Abstract: Method of automatic registration of three-dimensional images making possible visualization of the blood vessels, by comparison of a three-dimensional digital image obtained by means of a radiology apparatus and a three-dimensional digital image obtained by means of a nuclear magnetic resonance apparatus, in which, from a point of correspondence between the two three-dimensional images, an estimate is made by processing of the projected two-dimensional images of a rotation capable of registering the two three-dimensional images, then an estimate is made by processing of the projected two-dimensional images of a translation capable of registering the two three-dimensional images, and one of the two three-dimensional images is registered in relation to the other.

Abstract: A system and method of calibrating an imaging system, in which intrinsic parameters relating to the various types of image which can be taken are calibrated in predetermined angular positions of an emitter of radiation, and of a receiver of the radiation. The intrinsic parameters are estimated using a two-dimensional phantom in order to establish a distortion field for a particular angulation, the distortion field for any angulation being calculated by polynomial interpolation of the distortion fields, each established for a control point, a control point being defined by a particular angulation for each axis of rotation of the imaging system, having to be subject to calibration.

Abstract: Method of automatic registration of two- and three-dimensional angiography images by comparison of a two-dimensional digital subtracted angiography image with data on a three-dimensional image reconstructed from rotational angiography sequences, in which a field of distortions in the image is estimated, a conical projection matrix is estimated and an approximation is made of a rigid transformation in space equal to the difference between an initial registration based on the field of distortions and on the conical projection matrix and a perfect registration.

Abstract: The invention concerns a method and system for simulating the diameter enlargement of a lesion of a blood vessel by means of an endovascular prosthesis. A three-dimensional simulated image is visualized, showing the result of interaction between the lesion and the endovascular prosthesis after deployment of the latter. The three-dimensional simulated image visualized is the superposition of two three-dimensional images, a first three-dimensional simulated image showing the endovascular prosthesis deployed, taking into account the resistance of the lesion, and a second three-dimensional simulated image showing the enlarged lesion following the deployment of the endovascular prosthesis.

Abstract: A system and method of calibrating an imaging system, in which intrinsic parameters relating to the various types of image which can be taken are calibrated in predetermined angular positions of an emitter of radiation, and of a receiver of the radiation. The intrinsic parameters are estimated using a two-dimensional phantom in order to establish a distortion field for a particular angulation, the distortion field for any angulation being calculated by polynomial interpolation of the distortion fields, each established for a control point, a control point being defined by a particular angulation for each axis of rotation of the imaging system, having to be subject to calibration.

Abstract: Method and apparatus for viewing instrument markers used in medical imaging for calibrating a surgical or medical procedure assistance system. The apparatus comprises acquiring radiographic images, constructing a three-dimensional model from a set of radiographic images acquired, and locating, in a given coordinate system, at least one marker placed on an instrument used during the procedure. A set of opaque elements appearing on the images is placed in the field of the apparatus, and in that the position of a set of markers rigidly connected to the set of opaque elements is determined with respect to the locating coordinate system. A transformation is applied to the coordinate system for locating a marker whose position is automatically determined, depending on the positions thus determined for these markers in the coordinate system.

Abstract: Method of automatic registration of three-dimensional images making possible visualization of the blood vessels, by comparison of a three-dimensional digital image obtained by means of a radiology apparatus and a three-dimensional digital image obtained by means of a nuclear magnetic resonance apparatus, in which, from a point of correspondence between the two three-dimensional images, an estimate is made by processing of the projected two-dimensional images of a rotation capable of registering the two three-dimensional images, then an estimate is made by processing of the projected two-dimensional images of a translation capable of registering the two three-dimensional images, and one of the two three-dimensional images is registered in relation to the other.

Abstract: The radiology instrument contains a source emitting X-radiation, a radiological image receiver, a chassis arranged between the X-ray source and the image receiver in order to accommodate an object to be radiographed, and a positioning and guiding device which can be connected to the chassis and can intercept the X-radiation so as to position and guide probes intended to interact with the object. The positioning and guiding device has first means forming a retractable guide grid having holes whose respective axes converge towards the focal point of the source when the first means intercept the conical radiation, and a retractable positioning grid with holes.