Abstract: The invention relates to a method which enables distributed or dilute structures, for example a vascular system filled with a contrast medium, to be reproduced in a synthetic projection image which reproduces the parts of the vascular system which are situated in a selectable sub-volume more clearly than the X-ray images, formed from different perspectives, wherefrom the projection image is derived. The voxel image values associated with the voxels of the sub-volume are first determined and from these voxel image values there is calculated a synthetic projection image in which the selected sub-volume is reproduced.

Abstract: An X-ray imaging method, and device for carrying out the method, utilizes a first imaging device to form and digitally store a series of two-dimensional X-ray images in which an object to be examined is projected onto an X-ray image pick-up device from different perspectives, and a second imaging device to form a three-dimensional image of the same object. Quasi three-dimensional reproduction of anatomic structures is achieved by extracting a relevant structure of the object to be examined from the three-dimensional image, calculating synthetic, two-dimensional projection images of the extracted structure, the structure being projected with the same geometrical parameters as used for the relevant structure during the formation of the individual X-ray images, forming superposition images by superposing the synthetic projection images and the X-ray images formed under the same geometrical conditions, and displaying the series of superposition images.

Abstract: A distorted input image, produced by an X-ray exposure and composed of pixels defined by their position and their respective input image value, is transformed into a substantially distortion-free output image composed of pixels defined by their position and their output image value. Improvement is achieved in that the transformation utilizes a determination of the position of the corner points of the pixels of the output image (or the input image) as well as the surface area of a polygon defined by the corner points in the input image (output image).

Abstract: A memory arrangement for fast geometric transformation of an image is formed by a first memory for storing image values generated by an image-generating system, a second memory for storing image values corresponding to an image resulting from geometric transformation of image values from the first memory, and a third memory with the same number of memory addresses as the second memory and in which an assignment between the addresses of the first and second memories is stored.

Abstract: An X-ray diagnostic apparatus, comprises an X-ray source (1), an imaging surface (6) on which the intensity distribution of the X-rays to be applied to a test object (4) is imaged, an optical imaging device for imaging an overall image (10) of the imaging surface (6) onto the entrance surface of a first image sensor (11), a device (12) for the visual display of the overall image (10), and an imaging enlargement device for the enlarged visual display of a selectable detail of the overall image. Strongly enlarged and still high-resolution detail images are generated in that the selectable detail (20) of the overall image is directed onto a second image sensor 16) which discriminates a substantially higher number of pixels relative to the unit of surface area of the overall image.

Abstract: The invention relates to a method of forming images of layers of an object, and a device for performing this method. The layer images are formed from single-shadow images produced from different radiation source positions. The image values of the single-shadow images are first stored in a first as well as in a second memory. From the values of given image points in the second memory, a layer image value is calculated. The layer image value is added to the corresponding image points in a third memory. From the differences between these standardized sums in the third memory and the original image values in the first memory, there are formed correction values for correcting the image values in the second memory. Improved layer images are thus obtained.

Abstract: The invention relates to a method which enables spatial display in cases where X-ray images are formed from different perspectives which are situated far apart. To this end, from the single images a synthetic image of the examination zone is calculated for at least one position which neighbors one of the radiation source positions, which synthetic image is used for imaging the examination zone.

Abstract: The invention relates to a method of generating a layer image from a plurality of single images, the image processing errors which locally occur in the single images being substantially eliminated in the layer image. To this end, the image values for the individual layer image points are formed by that image value of the image points geometrically situated with the layer image point which corresponds to the next to the lowest absorption value.

Abstract: The invention relates to an X-ray subtraction method, and equipment for implementing this method, in which a moving structure is subtracted from the fixed background. The picture values corresponding to the minimum absorption are used as the mask image for each picture element from the projection images.