摘要:
A process is disclosed which involves automatic position-finding for a point of interest of an object that exhibits high contrast as compared with surrounding tissues, the process being carried out by means of a stereotactic photographic device that includes a digital image acquisition system. The process includes a number of steps for each image belonging to the pair of stereotactic images. An initial analysis of a histogram of the image pixels are made, and a subsequent determination is made of a threshold corresponding to the difference between the high contrast objects and the surrounding tissues. A subsequent determination is made of the threshold of the image, in order to obtain a binary image incorporating two gray levels. This is followed by the filtering of the threshold determined image in the preceding step, based on morphological criteria of the object in which the point of interest is located. This operation is designed to obtain a segmented projection of the object of interest. This is followed by the localization of the point of interest in the image reference mark. Utilization of the process is for stereotactic examinations performed during mammography.
摘要:
A derivation procedure for a three-dimensional digital mask from a series of two-dimensional masks in a radiographic device containing a source (S) of X-rays, a means of recording and a volume of interest hat contains the object to be X-rayed located between the source (S) and the means of recording consists of an extrapolation of each mask Mθ2 includes determining a last segment 1fin beyond the limits of the means of recording; and working out a two-dimensional mask Mγ associated with a position Sγ of the source, for any angle γ included in the angular range θ2 to θ1 (a position close to θ2). For every parallel segment 1 located between segment d (or d′ respectively) and segment 1fin, the procedure further includes deriving a three-dimensional mask (21) of the object for each voxel at the intersection of plane P1θ2 and the volume of interest; and projecting the three-dimensional mask onto the segment 1.
摘要:
A method of image processing in a radiological apparatus includes reconstructing a 3D image of a body from a set of radiography projection images, locating structures presumed to be representative of 3D radiological signs within the 3D image, determining a set of 2D candidate particles corresponding to projections of the presumed 3D radiological signs, assigning, through a fuzzy logic description, to the 2D candidate particles a degree of membership in 2D membership classes of a set of membership classes, each membership class being relative to a type of radiological sign, considering a 2D fuzzy particle being formed by the set of the 2D candidate particles and by their respective degrees of membership in a class, making an aggregate of the 2D fuzzy particles to obtain 3D fuzzy particles in a digital volume, and determining a degree of confidence for each 3D radiological sign from the 3D fuzzy particles.
摘要:
In an image-processing method for the detection of radiological signs in series of 3D data, an algorithm is used to detect radiological signs in a digital volume according to their contrasts. This algorithm is applied to reconstructed slices or directly to the series of projections. This algorithm is made by means of linear differential filters for signal analysis. It is used to color or enhance the intensity of the detected radiological signals according to the degree of malignancy.
摘要:
A sensor comprises two identical vibrating members operating with a common working frequency and joined to each other by a mechanical decoupling device. The device comprises a frame and two connecting bridges each supporting one member. The frame comprises a succession of mass portions and thinned portions so that the frequency of one mode of structural resonance of the frame is substantially equal to the common working frequency, and each connecting bridge is disposed in a node of vibration of the frame at the common working frequency. Thus, the vibrations of the two vibrating members are decoupled from each other.
摘要:
A region of interest is selected in an input image, such as a digital or analog image form a mammography apparatus. Display parameters for the input image or a part thereof are determined as a function of the region of interest. The image or a part thereof is displayed using the determined parameters. Choosing display parameters as a function of the region of interest optimizes the display of the possible region of interest without any adjustment by the operator.
摘要:
The stereotaxic images being digitized, a target pixel in a target region of interest is selected, a target window of chosen dimensional characteristics and containing the said target region of interest is generated around the selected target pixel, a set of pixels is determined in a second image, according to a predetermined selection criterion, a second window, of the same dimensional characteristics as the said target window, is generated around each selected pixel, a correlation processing between the grey-scale levels of the pixels of each second window and the grey-scale levels of the pixels of the target window is carried out so as to obtain a correlation value for each second window, and the region of interest homologous to the target region of interest is identified on the basis of the analysis of the set of correlation values thus obtained, so as to minimize the risks of matching error between the homologous regions of interest. The element of interest is then located on the basis of the positions of the two homologous regions.
摘要:
A monolithic miniature accelerometer machined in a plate of material, comprising a fixed part, two first mobile mass parts referred to as inertial masses, two hinge blades each having one end fastened to one of the two mobile mass parts, and two resonators each having one end fastened to one of the two mobile mass parts, a third mobile mass part fastened to the other end of each of the two resonators and of each of the two hinge blades, and a flexible stem situated between the first two mobile mass parts and connecting the third mobile mass part to the fixed part.
摘要:
The accelerometric sensor is of the type comprising a fixed mass, a mobile mass and two flectional vibrating beams each having ends that are linked to the masses. According to the invention, the masses and the beams consist of one single piece machined in a same plate of material of uniform thickness, e.g. in a piezoelectric material such as quartz. The single piece preferably comprises two second beams each having ends that are integral with the masses and placed on both sides of the vibratory beams. The flexural stiffness of the second beams is higher than that of the vibrating beams.
摘要:
A medical imaging device is provided. The medical imagining device includes an object support; a handle; a radiation source configured to emit radiation from a plurality of positions about the object support, wherein the positions are located substantially in a plane; a radiation detector configured to detect the radiation emitted by the radiation source; and displacement means configured to shift the handle relative to the radiation detector and to the radiation source.