Abstract: An image of a physical object is produced by receiving a plurality of raw images, dividing the plurality of raw images into a first subset of primary images and a second subset of secondary images according to a predetermined criterion. From the first subset of primary images an intermediate image is determined while from the second subset of secondary images a mask image is determined. Afterwards a registration of the intermediate image and the mask image is performed by using direct registration of predetermined features present in the intermediate image and the mask image. A fused image of the physical object is generated out of the mask image and the intermediate image.

Abstract: An x-ray system (100) comprises a gantry (102) on which an x-ray source (104) and an x-ray detector (106) are mounted. A control unit (110) comprises means (114) for effectuating a wiggling motion of the gantry, wherein an axis (116) connecting the x-ray source and the x-ray detector traces a surface (128) of a cone (118). The x-ray source and the x-ray detector have a fixed position with respect to the axis. The control unit comprises means (120) for acquiring a series of x-ray images during the wiggling motion of the gantry. An object recognition unit (122) detects an object (124) appearing in the series of x-ray images to obtain a tracked path. A depth estimation unit (126) uses the tracked path for estimating a depth parameter indicative of a position of the object in a direction substantially parallel to the axis (116).

Abstract: An imaging apparatus includes a multi-dimensional assembly supporting a plurality of x-ray sources that are individually addressable. The plurality of x-ray sources is further configurable to simultaneously emit x-ray spectra at different mean energies. Furthermore, the multi-dimensional assembly includes a plurality of x-ray detectors that are arranged to detect at least a part of the x-rays that are emitted from at least one of the x-ray sources.

Abstract: Images of static vascular maps (B), which were taken at different phases of the cardiac cycle and/or the respiratory cycle and were archived in a memory (6), are superimposed on a current image (A) of a catheter (2, 8) in the vascular system (9). In the method, a defined section of a map image (B) around the estimated actual position of the catheter is selected and is displayed superimposed on the current image (A) on a monitor (10). The map image (B) used for this is preferably selected by an electrocardiogram to match the particular cardiac cycle. The position of the catheter relative to the map image (B) is estimated using a distance image (D).

Abstract: A method for acquiring fusion images of a periodically moving body organ and an apparatus adapted to implement such method is described. In a preferred embodiment of the method, X-rays are irradiated to the body organ and a multiplicity of mask images is acquired by X-ray detection at a high image acquisition rate of at least 60 frames per second. Then, contrast medium is injected into vessels of the body organ and subsequently at least one contrast image of the body organ with the contrast medium included in the vessels is acquired by X-ray detection. A matching image from the multiplicity of mask images is determined which has been acquired at substantially the same stage of the movement of the body organ as the contrast image. By calculating the difference between the matching mask image and the at least one contrast image a subtraction image of the body organ can be obtained and displayed.

Abstract: Scatter compensation is achieved in an X-ray imaging system by providing collimation means in the form of shutters (12) to collimate the primary X-ray beam (1) such that the radiation (8) transmitted through a subject (4) to be imaged is incident substantially centrally on the active part (14) of an image detector (3), so as to define an active border (14b), in respect of which scatter levels can be measured. An electrical signal (104) representative of the scatter level is subtracted from the electrical signal (7) representative of the radiation (8) transmitted through the subject, to obtain a scatter-compensated image signal (106).

Abstract: Scatter compensation is achieved in an X-ray imaging system by providing collimation means in the form of shutters (12) to collimate the primary X-ray beam (1) such that the radiation (8) transmitted through a subject (4) to be imaged is incident substantially centrally on the active part (14) of an image detector (3), so as to define an active border (14b), in respect of which scatter levels can be measured. An electrical signal (104) representative of the scatter level is subtracted from the electrical signal (7) representative of the radiation (8) transmitted through the subject, to obtain a scatter-compensated image signal (106).

Abstract: An imaging apparatus is disclosed. The imaging apparatus comprises a multidimensional assembly that further comprises a plurality of x-ray sources that are individually addressable. The plurality of x-ray sources is further configurable to simultaneously emit x-ray spectra at different mean energies. Furthermore, the multi-dimensional assembly further comprises a plurality of x-ray detectors that are arranged to detect at least a part of the x-rays that are emitted from at least one of the x-ray sources.

Abstract: According to an exemplary embodiment a method for producing an image of a physical object comprises receiving a plurality of raw images, dividing the plurality of raw images into a first subset of primary images and a second subset of secondary images according to a predetermined criterion. From the first subset of primary images an intermediate image is determined while from the second subset of secondary images a mask image is determined. Afterwards a registration of the intermediate image and the mask image is performed by using direct registration of predetermined features present in the intermediate image and the mask image and fused image of the physical object is generated out of the mask image and the intermediate image.

Abstract: A medical viewing system for processing and displaying a sequence a sequence of medical angiograms representing a balloon, moving in an artery, this system comprising extracting means for automatically extracting balloon image data in a phase of balloon expansion, and computing means for automatically defining and storing coordinates of a Region of Interest (ROI) based on the expanded balloon image data, located around the expanded balloon; and display means for displaying the images. Contrast agent may be used as agent of balloon expansion. The system may have means to detect and keep track of balloon markers and means to look around those markers for further balloon image data extraction.

Abstract: The invention relates to the field of digital subtraction angiography. An image processing method is applied to a digitized mask (100) and to a sequence of digitized opacified images (101). A logarithmic function (105) is applied to the values of the pixels of the digitized mask and to the values of the pixels of the sequence of digitized opacified images, and then a subtraction (108) is made of the logarithmic value of each pixel of a digitized opacified image from the logarithmic value of the corresponding pixel in the digitized mask. In order to improve the quality of the images processed, a processing step (102) able to decrease certain pixel values of the digitized mask and of the digitized opacified images is applied before applying the logarithmic function.

Abstract: The invention relates to a device and to a method for combining two images, especially for superimposition of static vascular maps (B), which were taken at different phases of the cardiac cycle and/or the respiratory cycle and were archived in a memory (6), on a current image (A) of a catheter (2, 8) in the vascular system (9). In the method, a defined section of a map image (B) around the estimated actual position of the catheter is selected and is displayed superimposed on the current image (A) in an image (C) on a monitor (10). The map image (B) used for this is preferably selected by means of an electrocardiogram to match the particular cardiac cycle. The position of the catheter relative to the map image (B) can be estimated using a distance image (D).

Abstract: This invention relates to an apparatus and method for improved display of small dark structures such as in particular coronary blood vessels in digital X-ray images. A live image (S) is initially subjected to multiscale decomposition in which firstly multiple uses of low pass filtering with subsequent resolution reduction (RED), and secondly resolution increases using subsequent low pass filtration (EXP), give detailed images (D1, D2, D3, D4) of different resolution. In accordance with the first variant of the method, a mask (M) representative of the uninteresting image background is subtracted from the detailed image (D4) having the lowest degree of resolution. This ensures that the subtraction will only comprise correspondingly coarse structures with dimensions greater than the expected image motion. A further improvement can be achieved by applying a motion estimation (MOT EST) and motion compensation (MOT COMP) to the mask (M) and to the detailed image (D4) of the lowest degree of resolution.

Abstract: The invention relates to the field of digital subtraction angiography. An image processing method is applied to a digitized mask (100) and to a sequence of digitized opacified images (101). A logarithmic function (105) is applied to the values of the pixels of the digitized mask and to the values of the pixels of the sequence of digitized opacified images, and then a subtraction (108) is made of the logarithmic value of each pixel of a digitized opacified image from the logarithmic value of the corresponding pixel in the digitized mask. In order to improve the quality of the images processed, a processing step (102) able to decrease certain pixel values of the digitized mask and of the digitized opacified images is applied before applying the logarithmic function.

Abstract: This invention relates to an apparatus and method for improved display of small dark structures such as in particular coronary blood vessels in digital X-ray images. A live image (S) is initially subjected to multiscale decomposition in which firstly multiple uses of low pass filtering with subsequent resolution reduction (RED), and secondly resolution increases using subsequent low pass filtration (EXP), give detailed images (D1, D2, D3, D4) of different resolution. In accordance with the first variant of the method, a mask (M) representative of the uninteresting image background is subtracted from the detailed image (D4) having the lowest degree of resolution. This ensures that the subtraction will only comprise correspondingly coarse structures with dimensions greater than the expected image motion. A further improvement can be achieved by applying a motion estimation (MOT EST) and motion compensation (MOT COMP) to the mask (M) and to the detailed image (D4) of the lowest degree of resolution.

Abstract: The invention relates to a method, a device and a program for enhancing the image quality of images of the cardiovascular system of a patient which are produced by means of an X-ray device which includes a pulse generator for producing successive images at a given rate.

Abstract: An X-ray examination apparatus includes an X-ray source (1) for emitting X-rays. An object to be radiologically examined is arranged in an examination space. An X-ray detector (2) derives an image signal, for example an electronic video signal, from an X-ray image of the object. An X-ray filter locally attenuates the X-rays partly. The X-ray filter is arranged between the X-ray source and the X-ray detector and the X-ray filter is provided with filter elements whose X-ray absorptivity can be adjusted on the basis of an amount of X-ray absorbing liquid present within the individual filter elements.The X-ray examination apparatus includes an X-ray collimator for locally intercepting the X-rays. The X-ray collimator is arranged between the X-ray source and the examination space and is provided with collimator elements which can be switched between an X-ray transmitting state and an X-ray intercepting state.

Abstract: Noise reduction for use in an x-ray examination apparatus is provided for performing weighted temporally averaging in dependence on an amount of motion in parts of successive x-ray images. Further noise reduction is performed by combining temporal averaging with spatial filtering and motion detection. This reduces both noise breakthrough and the occurrence of trailers. In particular, noise breakthrough is appropriately reduced by hi-temporal filtering. Threshold-values for discriminating between noise and motion are computed on the basis of images generated by the x-ray detector.

Abstract: A contour is determined in the X-ray image by an image processing unit in an X-ray examination apparatus. An arithmetic processor responsive to the processing unit determines the position of X-ray absorbing diaphragm slats which enclose a minimum area situated around the contour of an object image. The diaphragm slats are moved to the correct position by a drive unit. As a result, overexposure of the X-ray image in the intensifier tube is counteracted and the medical details in the image become more distinct. Image harmonization are realized using X-ray absorbing wedges. Placing the wedges in excessively light parts of the X-ray image enables the dynamic range to be increased at areas of interest. The position of the wedges is calculated on the basis of a dose calculation based on exposure time, the voltage and the current applied to the X-ray source, these quantities being applied to the arithmetic processor via a control unit.

Abstract: Scattered radiation in an X-ray image causes a reduction of contrast. An estimate of the scattered radiation contribution is obtained by means of a version of the original image which is spread-out in space and which is multiplied by a location-dependent weighting factor. By subtracting this scattered radiation image from the X-ray image, a corrected image with enhanced contrast is obtained. The estimate of the scattered radiation image is adapted to the adjustment values for the imaging parameters of the X-ray system.