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 method and apparatus for determining the three-dimensional movement of a patient positioned on a table between an X-ray source and an image receiver of an X-ray imaging apparatus. The apparatus has an X-ray source positioned opposite an image receiver, the X-ray source and the image receiver being driven in rotation about an axis. The method and apparatus has the following operation: at least three radio-opaque markers are placed on the patient's body; at least one first radiographic image of the patient is taken for a first determined fixed position of the imaging apparatus; at least one second radiographic image of the patient is taken for a second determined fixed position of the imaging apparatus; and a matrix of the three-dimensional movement of the patient with respect to the X-ray source of the imaging apparatus is determined on the basis of the two-dimensional movements of the markers in the radiographic images, the X-ray source constituting a fixed reference frame.

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: 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: Certain embodiments of the present invention relate to a system and method for object and isocenter alignment in an imaging system. The system includes an electromagnetic, an electromagnetic receiver, and an imaging unit for determining an isocenter of an imaging scanner based on information from the electromagnetic receiver. The imaging unit identifies the isocenter based on a plurality of electromagnetic position measurements. The imaging unit identifies a center of an object to be imaged based on information from a second electromagnetic receiver. The imaging unit repositions the object based on the isocenter. In an embodiment, the emitter is located on the object, the first receiver is located on a detector, and the second receiver is located on a tool for identifying a center of the object or a portion of the object.

Abstract: In registration of images in digitized subtracted angiography, X-rays irradiate a patient's body. A first digitized mask image is acquired without an injection of the contrast agent into the body, then the contrast agent is injected into the body, and a second digitized contrast image is acquired. The mask image is divided with regular geometrical patterns and a registration is made of the mask image relative to the contrast image through the use of landmarks defined at the corners of the geometrical patterns. These two images are subtracted after registration, and the subtracted image is displayed. The robustness of the landmarks is furthermore tested, and if the robustness is insufficient, a subdivision is made of the regular geometrical patterns.

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: 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.