Abstract: A method for two-dimensional sheare wave elastography imaging comprises: a) acquiring B-mode ultrasound images of a target region in a body; b) selecting a region of interest inside the B-mode image; c) transmitting a shear wave excitation pulse focalized on an excitation region; d) measuring displacements of tracking focal points at different depths positions along laterally staggered tracking lines within the region of interest; e) determining elasticity parameters of the regions between two of the tracking focal points at the same depth and on at least two adjacent tracking lines as a function of the displacements caused by the shear wave at the tracking focal points; f) modifying the appearance of pixel(s) of the B-mode image inside the regions relatively to the grey-scale B-mode image as a function of elasticity parameters determined for the regions; and g) displaying the pixel(s) having a modified appearance at the corresponding pixel of the B-mode image.

Abstract: A method for quantifying the elasticity of a material by ultrasounds, comprising the generation of one excitation point, for generating a shear wave, a measurement of the shear wave at a plurality of lines of sight placed in a region of interest at different predetermined distances from the first excitation point, the calculation of the speed of the measured shear wave and the assessment, by calculation, of a mean stiffness value of the material in the region of interest on the basis of the measured speed of the shear wave. In the acquired image, a second excitation point is defined, in such a position that the region of interest is interposed between the first excitation point and the second excitation point.

Abstract: A method for two-dimensional sheare wave elastography imaging comprises: a) acquiring B-mode ultrasound images of a target region in a body; b) selecting a region of interest inside the B-mode image; c) transmitting a shear wave excitation pulse focalized on an excitation region; d) measuring displacements of tracking focal points at different depths positions along laterally staggered tracking lines within the region of interest; e) determining elasticity parameters of the regions between two of the tracking focal points at the same depth and on at least two adjacent tracking lines as a function of the displacements caused by the shear wave at the tracking focal points; f) modifying the appearance of pixel(s) of the B-mode image inside the regions relatively to the grey-scale B-mode image as a function of elasticity parameters determined for the regions; and g) displaying the pixel(s) having a modified appearance at the corresponding pixel of the B-mode image.

Abstract: Method for quantifying the elasticity of a material by ultrasounds, comprising the generation of one acoustic disturbance ultrasound beam (10) for the first excitation point (1), for generating a shear wave (11), a measurement of the shear wave (11) at a plurality of lines of sight placed in a region of interest (2) at different predetermined distances from the first excitation point (1), the calculation of the speed of the measured shear wave (11) and the assessment, by calculation, of a mean stiffness value of the material in the region of interest (2) on the basis of the measured speed of the shear wave (11). In the acquired image (3) a second excitation point (4) is defined, in such a position that the region of interest (2) is interposed between the first excitation point (1) and the second excitation point (4).

Abstract: A Magnetic Resonance apparatus includes a 3D structure having a cavity for receiving a body under examination, a mechanism for generating a static magnetic field in the patient receiving cavity, a mechanism for generating variable magnetic fields in the cavity, an antenna for transmitting electromagnetic nuclear spin excitation pulses, an antenna for receiving the electromagnetic signals generated by nuclear spin relaxation, a plate for locating and fixing magnetic dipoles for fine correction of magnetic field homogeneity, and a compartment for the magnetic correction dipole locating and fixing plate, the compartment being adapted to be opened for direct access to the magnetic correction dipole locating and fixing plate from the outside. The compartment may be opened either by removal of an end plate of the magnetic field generating mechanism, or via a lateral slot for insertion and removal of the magnetic correction dipole locating and fixing plate.

Abstract: A Magnetic Resonance apparatus includes a 3D structure having a cavity for receiving a body under examination, a mechanism for generating a static magnetic field in the patient receiving cavity, a mechanism for generating variable magnetic fields in the cavity, an antenna for transmitting electromagnetic nuclear spin excitation pulses, an antenna for receiving the electromagnetic signals generated by nuclear spin relaxation, a plate for locating and fixing magnetic dipoles for fine correction of magnetic field homogeneity, and a compartment for the magnetic correction dipole locating and fixing plate, the compartment being adapted to be opened for direct access to the magnetic correction dipole locating and fixing plate from the outside. The compartment may be opened either by removal of an end plate of the magnetic field generating mechanism, or via a lateral slot for insertion and removal of the magnetic correction dipole locating and fixing plate.

Abstract: A magnet structure for a Nuclear Magnetic Resonance imaging apparatus includes at least two opposing magnetic pole pieces, which are located at a certain distance from each other and delimit an imaging region. The pole pieces are formed by at least one massive layer of a magnetically permeable material, and at least one layer of magnetically permeable material having a pack of superimposed sheets or foils, electrically insulated from each other. Each of the sheets has cuts arranged over the surface of the sheet in positions that are at least partly non coincident with the cuts of at least one, or both adjacent sheets. The magnetically permeable sheets or foils have a first face and a second face and the cuts are so arranged on each sheet that the cuts of a sheet or foil are offset and not coincident with respect to the cuts of an adjacent sheet or foil, when said adjacent sheet is laid over the previous sheet in an overturned position, i.e.

Abstract: A magnet structure for a Nuclear Magnetic Resonance imaging apparatus includes at least two opposing magnetic pole pieces, which are located at a certain distance from each other and delimit an imaging region. The pole pieces are formed by at least one massive layer of a magnetically permeable material, and at least one layer of magnetically permeable material having a pack of superimposed sheets or foils, electrically insulated from each other. Each of the sheets has cuts arranged over the surface of the sheet in positions that are at least partly non coincident with the cuts of at least one, or both adjacent sheets. The magnetically permeable sheets or foils have a first face and a second face and the cuts are so arranged on each sheet that the cuts of a sheet or foil are offset and not coincident with respect to the cuts of an adjacent sheet or foil, when said adjacent sheet is laid over the previous sheet in an overturned position, i.e.

Abstract: A magnet structure for a Nuclear Magnetic Resonance imaging apparatus includes at least two opposing magnetic pole pieces, which are located at a certain distance from each other and delimit an imaging region. The pole pieces are formed by at least one massive layer of a magnetically permeable material, and at least one layer of magnetically permeable material having a pack of superimposed sheets or foils, electrically insulated from each other. Each of the sheets has cuts arranged over the surface of the sheet in positions that are at least partly non coincident with the cuts of at least one, or both adjacent sheets. The magnetically permeable sheets or foils have a first face and a second face and the cuts are so arranged on each sheet that the cuts of a sheet or foil are offset and not coincident with respect to the cuts of an adjacent sheet or foil, when said adjacent sheet is laid over the previous sheet in an overturned position, i.e.

Abstract: A method of compensating for eddy currents induced by the switching on and off magnetic fields in gradient coils in NMR imaging apparatuses, which method includes at least one compensation cycle including the steps of performing at least one detection of the magnetic field generated by the current flowing in a gradient coil, i.e., a gradient field; extrapolating the course of the effectively generated gradient field from the data of said at least one detection; generating a gradient fields excitation current compensating the eddy current effects on the gradient fields on the basis of the comparison of the effectively generated gradient fields and of the target gradient field.

Abstract: A method for compensating for magnetic noise fields in spatial volumes includes determining the strength of a magnetic field outside said spatial volume; defining the correlation between the noise field outside the spatial volume and the corresponding noise field inside said spatial volume; generating a magnetic compensation field for neutralizing the noise field in said spatial volume. The method further provides separate detection of noise fields with frequencies in the range of at least two different frequency bands.

Abstract: A magnet structure for a Nuclear Magnetic Resonance imaging apparatus includes at least two opposing magnetic pole pieces, which are located at a certain distance from each other and delimit an imaging region. The pole pieces are formed by at least one massive layer of a magnetically permeable material, and at least one layer of magnetically permeable material having a pack of superimposed sheets or foils, electrically insulated from each other. Each of the sheets has cuts arranged over the surface of the sheet in positions that are at least partly non coincident with the cuts of at least one, or both adjacent sheets. The magnetically permeable sheets or foils have a first face and a second face and the cuts are so arranged on each sheet that the cuts of a sheet or foil are offset and not coincident with respect to the cuts of an adjacent sheet or foil, when said adjacent sheet is laid over the previous sheet in an overturned position, i.e.

Abstract: A method of compensating for eddy currents induced by the switching on and off magnetic fields in gradient coils in NMR imaging apparatuses, which method includes at least one compensation cycle including the steps of performing at least one detection of the magnetic field generated by the current flowing in a gradient coil, i.e., a gradient field; extrapolating the course of the effectively generated gradient field from the data of said at least one detection; generating a gradient fields excitation current compensating the eddy current effects on the gradient fields on the basis of the comparison of the effectively generated gradient fields and of the target gradient field.

Abstract: A method for compensating for magnetic noise fields in spatial volumes includes determining the strength of a magnetic field outside said spatial volume; defining the correlation between the noise field outside the spatial volume and the corresponding noise field inside said spatial volume; generating a magnetic compensation field for neutralizing the noise field in said spatial volume. The method further provides separate detection of noise fields with frequencies in the range of at least two different frequency bands.

Abstract: The invention relates to a process for manufacturing magnetic field generating devices in Nuclear Magnetic Resonance imaging apparatuses and to an image generating device according to said method. According to the invention, at least one layer of each pole piece is composed a plurality of adjacent or overlapping sheets, electrically insulated from each other. These sheets or foils may have slots, notches or apertures which cause bridges of a material having a lower electric conductivity to be formed between the areas separated by the notches and/or apertures. The bridges of material may be removed after sheet assembly by a cutting operation, particularly by laser cutting.

Abstract: The invention is directed to a method, an instrument and a system for performing verification measurements and corrections of magnetic fields in magnets for Nuclear Magnetic Resonance imaging machines. According to the invention, test elements are used whereof Nuclear Magnetic Resonance images are detected. Then, these actually detected images are compared with the theoretical images which would be obtained in ideal conditions. The number, magnitude and position of correcting magnetic charges are determined from the differences between the actual image and the theoretical image. The invention is also directed to a specific test element and to a Nuclear Magnetic Resonance imaging machine.

Abstract: The invention relates to a process for manufacturing magnetic field generating devices in Nuclear Magnetic Resonance imaging apparatuses and to an image generating device according to said method. According to the invention, at least one layer of each pole piece is composed a plurality of adjacent or overlapping sheets, electrically insulated from each other. These sheets or foils may have slots, notches or apertures which cause bridges of a material having a lower electric conductivity to be formed between the areas separated by the notches and/or apertures. The bridges of material may be removed after sheet assembly by a cutting operation, particularly by laser cutting.

Abstract: The invention is directed to a method, an instrument and a system for performing verification measurements and corrections of magnetic fields in magnets for Nuclear Magnetic Resonance imaging machines. According to the invention, test elements are used whereof Nuclear Magnetic Resonance images are detected. Then, these actually detected images are compared with the theoretical images which would be obtained in ideal conditions. The number, magnitude and position of correcting magnetic charges are determined from the differences between the actual image and the theoretical image. The invention is also directed to a specific test element and to a Nuclear Magnetic Resonance imaging machine.

Abstract: High-pass filtering process for focusing images, particularly digital images, or similar, which are composed of a plurality of single dot areas, named pixels (Pi,j), having different individually variable luminous intensities I (Pi,j). The filtering process provides, for each pixel (Pi,j) a correction C (Pi,j) of the intensity value of said pixel (Pi,j), which is calculated statistically, on the basis of combinations of high-pass filterings performed in at least one, preferably in at least four different directions (0.degree., 45.degree., 90.degree., 135.degree.). According to the invention, the high-pass filter determines the correction (C,(Pr,r)) of each pixel (Pr,r; Px,x) on the basis of a mean of the intensities of at least pairs of pixels being next to, that is at predetermined distances from and on opposite sides of the filtered pixel (Pr,r; Px,x), with reference to each of the predefined directions (0.degree., 45.degree., 90.degree.,135.degree.