Abstract: A method and device for calibrating images acquired by radiography comprising an X-ray source, an image acquisition, a support placed between the source and the image acquisition, on which support an object to be X-rayed is intended to be positioned. A region of interest, in which the object is likely to be found, is determined between the support and the image acquisition, the center of gravity of this region is determined and at least one calibration factor of the image or images is determined as a function of the position thus determined.

Abstract: A method and apparatus for imaging including reconstruction of an image of an object from a set of projections acquired for different positions of an acquisition apparatus around the object to be imaged and in which a projection source is situated at a finite distance relative to the acquisition apparatus. The method includes undertaking a set of rectifications of projections acquired for different positions of the acquisition apparatus, rectifications comprising transforming the data of the projection acquired projection into projection data on a virtual rectification support placed in a preset orientation in concordance with a set of reconstruction calculation points distributed over the image to be reconstructed.

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: A process for cardiac movements to be used with a radiography apparatus (1) wherein acquiring of a series of successive images In of the region of the heart, an analysis of at least some of the images thus acquired to identify a heart movement; and a determination of the cardiac cycle starting from this movement.

Abstract: A method and apparatus for determining a set of functional parameters using a fluoroscopic radiography apparatus of the type comprising an X-ray source, a detector or recorder of the radiation facing the source, the source and the detector or recorder being installed on a mobile support capable of movement with respect to a table placed between the source and the detector or recorder on which a patient with a region of interest to be X-rayed will be placed. The method comprises a) movement of the support following a given movement with respect to the table, repeated during a given time; b) acquisition by the detector or recorder of a series of images of the region of interest during movement of the support with respect to the table; c) reconstitution of a series of three-dimensional models of the region of interest, starting from a series of acquired images; and d) determination of all functional parameters.

Abstract: An element is dissolved displayed having a periodic structure, such as a stent, images of which are acquired by means of a radiography machine of the type comprising an X-ray source and an image detector and an image display placed opposite the source.

Abstract: In the field of medical imaging minimizing the number of acquisitions required to calibrate a radiological device. Calibration of the radiological imaging device is provided by moving the device with respect to a calibration object and performing a series of acquisitions, each acquisition being associated to a calibration position of the device. Based on the acquisitions performed, determining the projection parameters associated to each calibration position of the device. For an additional position that has not been taken by the device during the acquisition, determining the projection parameter values associated to this additional position according to the parameters associated to the calibration positions.

Abstract: The invention concerns a method of three-dimensional image reconstruction from a set of acquired two-dimensional images. A subsampling is taken of the set of acquired two-dimensional images so as to reduce their resolution. A first analytical algorithm of three-dimensional image reconstruction from low-resolution (LR) acquired two-dimensional images is applied in order to obtain a low-resolution three-dimensional image. A reconstruction support is determined by selecting in the low-resolution three-dimensional image a set of particular voxels. One then applies a second analytical algorithm of three-dimensional image reconstruction from acquired two-dimensional images and considering only the voxels of the reconstruction support in order to obtain the high-resolution (HR) three-dimensional image.

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: A process for reconstructing a tridimensional image of an object moving with a substantially cyclic motion, for example the vessels of the human heart, in which, for an acquisition duration extending over several cycles of the movement of the object, an acquisitio of a plurality of initial digital radiographic images is performed using a snapshot apparatus rotating around the object. Initial images having the same temporal occurrence in the course of each cycle are selected respectively in successive cycles so as to form a group of images which is associated with this same temporal occurrence. Several different groups of initial images corresponding respectively to several different temporal occurrences are formed. An intermediate tridimensional representation of the object is reconstructed on the basis of each group of initial images and of an iterative image reconstruction algorithm.

Abstract: A method and apparatus for reconstructing an image of an organ or body part from at least two images of the organ or body part taken using radiography in two positions of the organ or body part separated by a rolling movement of the organ or body part. The rolling movement of the organ or body part is determined between two positions, extracting motion vectors for the surface of the organ or body part, interpolating motion vectors between the motion vectors extracted, and reconstructing an image of the organ or body part. The method and apparatus allows the three-dimensional structure of the tissue to be reconstructed while reducing ambiguities due to the presence of a lesion overlaying the tissue.

Abstract: Several acquisitions of digital radiographic images of an element of interest are made, by using a moving camera rotating around the element of interest in a plane parallel to the plane of a section, a matching stage is carried out in which projected elements are located in all the acquired images, corresponding respectively to the projections of the element of interest in those acquired images. The width of each projected element is determined and the section of the element of interest is reconstructed from the different widths determined.

Abstract: A method of cardiac radiological examination for coronarography comprises the steps of:

Abstract: The process comprises a calibration of the apparatus, in which a virtual volume surrounding the object is generated and broken down into voxels, an acquisition of the set of numbered projected two-dimensional images, and a reconstruction of the three-dimensional image from the projected acquired two-dimensional images, and from an iterative algebraic image reconstruction algorithm. A first iteration of the algorithm is performed with a predetermined initial image resolution so as to obtain, at the end of this first iteration, first density values for the voxels of the volume, at least one part of the voxels of the virtual volume is subdivided into several sets, respectively, corresponding to different image resolutions that are multiples or sub-multiples of the initial resolution, and during each subsequent iteration of the algorithm, the algorithm is successively aplied to each of the sets of voxels.

Abstract: A method and device for displaying an element having a periodic structure, such as a stent, images of which are acquired by means of a radiography machine of the type comprising an X-ray source and an image detector and an image display placed opposite the said source, wherein the images obtained are displayed with an overall magnification of: 1 f S f C ⁢   ⁢ S ⁢   ⁢ F × E ⁢   ⁢ S ⁢   ⁢ D × π 180 ,

Abstract: A method and device for calibrating images acquired by radiography comprising an X-ray source, an image acquisition, a support placed between the source and the image acquisition, on which support an object to be X-rayed is intended to be positioned. A region of interest, in which the object is likely to be found, is determined between the support and the image acquisition, the center of gravity of this region is determined and at least one calibration factor of the image or images is determined as a function of the position thus determined.

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: A method and apparatus for determining a magnification factor in a radiography device of the type comprising an X-ray source and means for acquiring images placed facing the source, the source and the means for acquiring images being mounted so as to rotate about at least one axis with respect to a support on which an object to be X-rayed is intended to be positioned. The method and the apparatus implementing the method comprises: acquiring at least two images corresponding to two different angular positions of the source and of the recording means with respect to the support; identifying on these images projections of at least one point of the X-rayed object; and determining the magnification factor of at least one of the images, first, as a function of the angular displacement of the source and of the recording means between the acquisitions of the images in question and, secondly, as a function of the positions on these images of the identified projections.

Abstract: The method comprises a phase of reconstruction of a static three-dimensional image of the object from a first set of digitized two-dimensional projected images of the object respectively obtained for different positions of a camera around the object, a phase of acquisition of at least a second set of n static two-dimensional projected images respectively obtained for a same first position of the camera and at n successive propagation times of the contrast medium, and a phase of reconstruction of the dynamic three-dimensional image of the object from each static two-dimensional image of the second set and the reconstructed static three-dimensional image.

Abstract: Method of controlling of a radiology device, of the type comprising a means of emission of an X-ray beam and a means of reception of the X-ray beam, after it has crossed a part of the object's body, in which a three-dimensional image of a part of the object's body is reconstructed from a series of two-dimensional films, two-dimensional views of the three-dimensional image are produced at different angles of incidence, the angle of incidence allowing the best visualization of the part of the object's body are selected, the angles of incidence are stored in memory, and the angles of incidence are supplied to the radiology device for its positioning with a view to an intervention or procedure on the part of the object's body under fluoroscopy allowing a visualization in real time of two-dimensional.