Abstract: The method consists of subjecting the organ to pre-exposure with a low dose of rays, creating in the field of the pre-exposure image a multi-cellular image in which each cell represents the mean signal level of a predetermined number of pixels of the detector, selecting from the columns the cell of minimum signal level most distant from a reference point, establishing about this cell a band parallel to the reference point and selecting from the band the cell having the absolute minimum signal level.

Abstract: A method of operating a display including providing a display; acquiring an image of a structure by measuring, for each of a plurality of elements, a magnitude representing an element of the structure; providing a plurality of contrast setting control buttons including a first contrast setting button that directly and independently modifies dark parts of the image of the structure and a second contract setting button that directly and independently modifies light parts of the image of the structure; digitizing the magnitudes according to a direct mode by assigning a digitized value d representing the measured magnitude of each of the elements; displaying a direct image by assigning a luminosity l corresponding to the digitized value d of each of the elements and transmitting to the display the luminosity l of each of the elements; transforming the direct image to a transformed image by assigning to each the of elements a digital value i which corresponds to the digitized value d of each of the elements; and d

Abstract: To filter a signal delivered in interleaved form, there is provision for the introduction, in series, of a filter on half frames having a bandpass transfer function on the horizontal plane and a high-pass transfer function on the vertical plane. It is shown that this filter then carries out a general bandpass transfer function on the total image signal. Steps are taken to make the center frequency of this filter correspond to a desired resolution of the image. It is shown then that by acting in this way it is possible to heighten the contours of the structures. The invention can be applied particularly to medical radiography.

Abstract: The formation of a NMR machine phantom having a homogeneous material serving for forming the image which is confined to precise positions. The precise positions are evenly distributed in the form of a matrix so that a particular image formation method may be used. The combination of the image formation method and the matrix distribution allows for obtaining information with respect to the field at numerous points and increases the speed at which these points are determined.

Abstract: In a method of direct line-by-line acquisition of an image by nuclear magnetic resonance, each line is selected at the intersection of two planes in which the atoms of the selected element such as hydrogen, for example, have been successively excited in order to produce a spin echo, said echo phenomenon being produced solely by the atoms of said line. The selection planes are separate and distinct from the tomographic plane.

Abstract: Axial transverse tomography system analyzing a transverse section of a body by means of a source of X-rays and a detector of X-rays located on opposite sides of the section and in motion about the section. The data received by the detector are employed simultaneously with their formation for an optical reconstitution of the picture from the densities of absorption of the analyzed section. A filter having a predetermined spatial transparency law, associated with the reconstitution optical system, enables a good picture to be obtained.

Abstract: The object of the invention is an ultrasonic echo-tomographic device. An alignment of transducers coupled to the body under observation emits flat ultrasonic radiation. The wave fronts of the echoes received in response at each line parallel to the front of the transducers are transformed by means of an electrical chain, without alteration of phase, in a crystalline medium. A laser and an optical system form by Bragg diffraction the images of these lines which are picked up by a vibrating mirror and projected onto the target of a television camera. The invention is applicable in echo-tomography and enables 1000 images per second to be obtained.