Abstract: A system and method for correcting the registration of a 3D image and a 2D image acquired with medical imaging systems is disclosed. The system and method determines acquisition geometry of the imaging system by calculating an initial projection matrix associated with the 2D image. The system performs a projection of the 3D image using the initial projection matrix resulting in a 2D projection of the 3D image. The system registers the 2D projection of the 3D image and the 2D image. A new projection matrix is determined based on the registration of the 2D image and the 2D projection of the 3D image. The 3D image is then registered with the 2D image using the new projection matrix. An associated medical imaging system is disclosed. Method embodiments use previously acquired 3D images or images acquired using imaging modalities different than the one used to acquire the 2D image.

Abstract: A system to track movement of an object travelling through an imaged subject is provided. The system includes an imaging system to acquire a fluoroscopic image and operable to create a three-dimensional model of a region of interest of the imaged subject. A controller includes computer-readable program instructions representative of the steps of calculating a probability that an acquired image data is of the object on a per pixel basis in the fluoroscopic image, calculating a value of a blending coefficient per pixel of the fluoroscopic image dependent on the probability, adjusting the fluoroscopic image including multiplying the value of the blending coefficient with one of a greyscale value, a contrast value, and an intensity value for each pixel of the fluoroscopic image. The adjusted fluoroscopic image is combined with the three-dimensional model to create an output image illustrative of the object in spatial relation to the three-dimensional model.

Abstract: A method for determining acquisition geometry of an imaging system from a set of calibration matrices for an arbitrary position of the system, a projection matrix makes a point in a 2D image correspond to a point of an object in a space. This matrix is produced for any unspecified position of the system from knowledge of a limited number of pre-computed calibration matrices. For instance, a projection matrix may be computed by interpolating coefficients of calibration matrices and/or applying a transformation with a rigid model defined comprehensively or locally to a particular calibration matrix.

Abstract: A method for the correction of registration of radiography images comprises means to determine a residual rigid transformation in comparing the pre-operation 3D image with a fluoroscopic image. This residual transformation is determined according to a registration based on the content of the image. Once the residual transformation is computed, it is combined with a geometrical registration. The use of the geometrical registration in this combination enables the making of a real-time registration comprising the motion of the C-arm without any additional registration. And the use of the registration based on the content of the image enables the precision of said geometrical registration to be refined.

Abstract: A system to track movement of an object travelling through an imaged subject is provided. The system includes an imaging system to acquire a fluoroscopic image and operable to create a three-dimensional model of a region of interest of the imaged subject. A controller includes computer-readable program instructions representative of the steps of calculating a probability that an acquired image data is of the object on a per pixel basis in the fluoroscopic image, calculating a value of a blending coefficient per pixel of the fluoroscopic image dependent on the probability, adjusting the fluoroscopic image including multiplying the value of the blending coefficient with one of a greyscale value, a contrast value, and an intensity value for each pixel of the fluoroscopic image. The adjusted fluoroscopic image is combined with the three-dimensional model to create an output image illustrative of the object in spatial relation to the three-dimensional model.

Abstract: A method and apparatus for determining acquisition geometry of an imaging system from a set of calibration matrices for an arbitrary position of the system, a projection matrix makes a point in a 2D image correspond to a point of an object in a space. This matrix is produced for any unspecified position of the system from knowledge of a limited number of pre-computed calibration matrices. For instance, a projection matrix may be computed by interpolating coefficients of calibration matrices and/or applying a transformation with a rigid model defined comprehensively or locally to a particular calibration matrix.

Abstract: A method and system for medical image display comprising means for acquiring two-dimensional images; means for displaying images; means for managing the display of a three-dimensional representation on the means display and for automatically orienting the three-dimensional representation according to at least one operating parameter of the means for acquisition means so that the three-dimensional representation is viewed on the means for display from a viewpoint corresponding to that from which the means for image acquisition acquire or have acquired a two-dimensional image.

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 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: A method and system for medical image display comprising means for acquiring two-dimensional images; means for displaying images; means for managing the display of a three-dimensional representation on the means display and for automatically orienting the three-dimensional representation according to at least one operating parameter of the means for acquisition means so that the three-dimensional representation is viewed on the means for display from a viewpoint corresponding to that from which the means for image acquisition acquire or have acquired a two-dimensional image.

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: 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 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.