Abstract: An image processing method for interventional imaging in which a region of interest of a patient is viewed. The method comprises acquiring a succession of images of a region of interest of the patient. The method also comprises detecting and tracking, on the successive images, at least one surgical instrument introduced inside the region of interest of the patient, in order to isolate said instrument therein; and comparing two successive images on which the surgical instrument has been isolated in order to identify at least one common shape therein. The method further comprises estimating the displacement of said common shape between both of these successive images; and re-alignment processing of the different successive images depending on the thereby determined estimations of displacements, these displacement estimations being considered as corresponding to the displacement caused by the physiological movement of the patient with the exception of any other movement.

Abstract: In the field of medical imaging using fluoroscopy, a method for reducing noise in a sequence of fluoroscopic images acquired by an X-ray detector comprises for each image (xn) of the sequence: applying temporal filtering to the image (xn) at instant n, the temporal filtering comprising fluoroscopic noise reduction processing; applying spatial filtering to the image (yn) at instant n, the spatial filtering comprising: transforming the image (yn) acquired at the instant n from the spatial domain into the curvelet domain using a curvelet transform, each transformed image being represented by a set of coefficients, thresholding the coefficients of the image (yn) using a thresholding function, the thresholding function cancelling the coefficients below a third predetermined threshold, and preserving or adjusting the coefficients above the third predetermined threshold, transforming the image (Zn) whose coefficients have been thresholded from the curvelet domain into the spatial domain using an inverse curvelet tra

Abstract: In the field of medical imaging using fluoroscopy, a method for reducing noise in a sequence of fluoroscopic images acquired by an X-ray detector comprises for each image (xn) of the sequence: applying temporal filtering to the image (xn) at instant n, the temporal filtering comprising fluoroscopic noise reduction processing; applying spatial filtering to the image (yn) at instant n, the spatial filtering comprising: transforming the image (yn) acquired at the instant n from the spatial domain into the curvelet domain using a curvelet transform, each transformed image being represented by a set of coefficients, thresholding the coefficients of the image (yn) using a thresholding function, the thresholding function cancelling the coefficients below a third predetermined threshold, and preserving or adjusting the coefficients above the third predetermined threshold, transforming the image (zn) whose coefficients have been thresholded from the curvelet domain into the spatial domain using an inverse curvelet tra

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 is presented. 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: 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; and a matrix of the three-dimensional movement of the patient 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 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 navigate an image-guided object traveling in an area of interest of an imaged subject in relation to an acquired image of the imaged subject as created by an imaging system is provided. The system includes a navigation system to track movement of the object in the imaged subject in spatial relation to a navigation coordinate system, and a controller. The controller is operable in detecting an image of the object in the at least one image of the imaged subject, calculating a spatial relation between the location of the image of the object and a tracked location of the object, and modifying the spatial relation of the image coordinate system relative to the navigation coordinate system so as to reduce the difference between the location of the image of the object and the tracked location of the object by the navigation system.

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 system for navigating an image-guided object through an imaged subject supported on table in relation to an image acquired by an image detector is provided. The system includes a first tracking element attached to the patient, and a second tracking element attached at the table. The first and second tracking elements define first and second coordinate systems. A controller is operable to register the second coordinate system with a third coordinate system defined by the image detector, measure a spatial relation between the first tracking element and the second tracking element, register the first coordinate system with the third local coordinate system defined by the image detector based on the spatial relation between the first and second tracking elements, and generating a composite image comprising a virtual image of the object in spatial relation to the image of the imaged subject acquired by the image detector.

Abstract: An image processing method for interventional imaging in which a region of interest of a patient is viewed. The method comprises acquiring a succession of images of a region of interest of the patient. The method also comprises detecting and tracking, on the successive images, at least one surgical instrument introduced inside the region of interest of the patient, in order to isolate said instrument therein; and comparing two successive images on which the surgical instrument has been isolated in order to identify at least one common shape therein. The method further comprises estimating the displacement of said common shape between both of these successive images; and re-alignment processing of the different successive images depending on the thereby determined estimations of displacements, these displacement estimations being considered as corresponding to the displacement caused by the physiological movement of the patient with the exception of any other movement.

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: 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: 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 generate an image dependent on tracking movement of an object travelling through an imaged subject is provided. The system comprises a tracking system operable to detect a position or an orientation of the object travelling through the imaged subject, and an imaging system operable to create a three-dimensional model of a selected anatomical structure of the imaged subject. A controller is operable to store a plurality of computer-readable program instructions for execution by a processor, the plurality of program instructions representative of the steps of: calculating at least one two-dimensional view of a volume of interest extracted from the three-dimensional model, the volume of interest dependent relative to the tracked position of the object, and generating an output image illustrative of the at least one two-dimensional view of the volume of interest.

Abstract: A method for registering images acquired by at least one imaging system. The method includes:positioning at least a first sensor (S) interdependent on the imaging system; positioning at least a second sensor (P) so as to make it interdependent on the movements of an organ of a patient of which at least two images are taken; acquiring the positions of said sensors (S, P) during acquisitions of the images; and registering the images according to the positions of the sensors (S, P). A system for registering images acquired by at least one imaging system includes means for acquiring the position of at least a first sensor interdependent on the imaging system and of at least a second sensor interdependent on the movements of an organ of a patient of which two images are taken, the registration being performed according to the positions of the sensors at the moment when the images are acquired.

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 system to navigate an image-guided object traveling in an area of interest of an imaged subject in relation to an acquired image of the imaged subject as created by an imaging system is provided. The system includes a navigation system to track movement of the object in the imaged subject in spatial relation to a navigation coordinate system, and a controller. The controller is operable in detecting an image of the object in the at least one image of the imaged subject, calculating a spatial relation between the location of the image of the object and a tracked location of the object, and modifying the spatial relation of the image coordinate system relative to the navigation coordinate system so as to reduce the difference between the location of the image of the object and the tracked location of the object by the navigation system.

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: 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: A system for navigating an image-guided object through an imaged subject supported on table in relation to an image acquired by an image detector is provided. The system includes a first tracking element attached to the patient, and a second tracking element attached at the table. The first and second tracking elements define first and second coordinate systems. A controller is operable to register the second coordinate system with a third coordinate system defined by the image detector, measure a spatial relation between the first tracking element and the second tracking element, register the first coordinate system with the third local coordinate system defined by the image detector based on the spatial relation between the first and second tracking elements, and generating a composite image comprising a virtual image of the object in spatial relation to the image of the imaged subject acquired by the image detector.

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.