Abstract: A magnetic resonance imaging (MRI) system is used to produce an image representative of the vasculature of a subject by applying a non-contrast MRI pulse sequence to acquire MRI k-space data from non-stationary nuclei flowing in a selected spatial region of a subject after nuclei within the region have been subjected to spatially non-uniform pre-saturation of nuclear magnetic resonance (NMR) magnetization. Such pre-saturation suppresses subsequent MRI signals emanating from background nuclei located within said region during said pre-saturation, while enhancing MRI signal from flowing nuclei therewithin as a function of speed, slice thickness and elapsed time until image capture as a function of the spatially shaped profile of non-uniform pre-saturation across the imaged volume. Thus, acquired MRI k-space data can then be used to reconstruct an image representing vasculature of the subject.

Abstract: A method comprises: performing a number of B i field mapping sequences (24) using a set of radio frequency transmit coils (11) to acquire a B1 field mapping data set wherein said number is less than a number of radio frequency transmit coils in the set of radio frequency transmit coils; and determining coil sensitivities (30) for the set of radio frequency transmit coils based on the acquired B1 field mapping data set. In some embodiments, the performed B1 field mapping sequences are defined by (i) performing a linear transform (40) on the set of radio frequency transmit coils to generate a set of orthogonal virtual radio frequency transmit coils (42) and (ii) selecting (44) a sub-set (46) of the set of orthogonal virtual radio frequency transmit coils that define the performed B1 field mapping sequences.

Abstract: Temperature control device (20) for an NMR sample tube (22), wherein multiple interleaved, concentric flow channels (28, 31; 40, 41, 42; 50, 51) for temperature control fluid extending coaxially with respect to a cylindrical interior space (21) for holding the NMR sample tube are constituted around said interior space (21), wherein said temperature control device is constituted such that it is closed toward the interior space in an axial end region (26) and, an axial end region (23) at the opposite end thereto, open to the interior space for inserting the NMR sample tube into said interior space (21), wherein, in a counter flow region (GB), adjacent flow channels (28, 31; 40, 41, 42; 51) are interconnected through a fluid passage (34, 43, 44) at one axial end in such a way that the direction of a fluid flow in the flow channels of the counter flow region is reversed with respect to the corresponding adjacent flow channel in the counter flow region, wherein the outermost flow channel (28; 51) of the counter fl

Abstract: The present embodiments relate to a balanced-to-unbalanced transformer for converting a symmetrical high-frequency signal into an asymmetrical high-frequency signal. The balanced-to-unbalanced transformer includes two coil windings made of wire. The two coil windings are electrically insulated from each other and are wound on a winding form. Each of the two coil windings has an input at one end of the winding form for the symmetrical high-frequency signal and an output at another end of the winding form for the asymmetrical high-frequency signal. The two coil windings lie on top of one another in a radial direction of the winding form.

Abstract: The present embodiments relate to an apparatus that includes a local coil for a magnetic resonance tomography system and an implantable device.

Abstract: A stress detecting system and method operable to detect stresses in a conduit or pipe includes a tool movable along a conduit or pipe and operable to generate a magnetic field. The tool is operable to sense magnetic Barkhausen noise within the conduit, such as within a wall of the conduit, in response to the tool generating the magnetic field. The stress detecting system is operable to detect a change in stress along the conduit responsive to an output of the tool. The system may detect changes in stress that are caused by geological changes or shifting or thermal changes at or near the conduit to determine changes in stress along the conduit and changes in stress along the conduit over time and during use of the conduit.

Abstract: A magnetic resonance imaging apparatus includes a spectrum acquisition unit and a determining unit. The spectrum acquisition unit acquires a frequency spectrum of magnetic resonance signals from a metabolic product in a target region in an object. The determining unit determines the number of (a) integrations and/or (b) phase encodes of magnetic resonance signals for obtaining the frequency spectrum depending on a factor influencing the frequency spectrum.

Abstract: The present embodiments include a magnetic resonance antenna having parallel-running longitudinal antenna rods arranged in a birdcage structure and antenna ferrules connecting the parallel-running longitudinal antenna rods at ends of the parallel-running longitudinal antenna rods in radio frequency terms. The magnetic resonance antenna includes a plurality of radio-frequency switching elements configured to interrupt at least a part of the parallel-running longitudinal antenna rods to detune a natural resonance frequency with respect to an operating magnetic resonance frequency in radio frequency terms. At least some radio-frequency switching elements of the plurality of radio-frequency switching elements are arranged at end sections of the parallel-running longitudinal antenna rods.

Abstract: A magnetic resonance device with a measurement chamber, an antenna arrangement that has a plurality of antenna elements arranged at least in certain areas around the measurement chamber, a gradient coil system arranged outside the antenna arrangement as seen from the measurement chamber, and a high-frequency shield system arranged between the antenna arrangement and the gradient coil system are provided. The high-frequency shield system has a reflector array with a plurality of passive reflector resonance circuits, each of which is configured such that resonance frequencies of the plurality of passive reflector resonance circuits lie below an operating magnetic resonance frequency of the magnetic resonance device and that the plurality of passive reflector resonance circuits has an inductive overall impedance.

Abstract: A device of estimating a dose of ionizing radiation absorbed in an intra bone volume. The device comprises a static magnetic field source adapted to generate a substantially static magnetic field in a probing space having a volume of less than 2 cubic millimeter (mm3), the probing space being placed in front of a distal end of static magnetic field source, a micro resonator mounted in adjacent to the distal end, and at least one transmission line which feeds the resonator so as to generate an microwave magnetic field at the probing space and to transmit a signal returned from said microwave magnetic field and indicative of radiation induced paramagnetic defects in said probing space so as to allow a spectrometer to compute a dose of ionizing radiation absorbed in a portion of a bone placed in the probing space according to an analysis of the signal. The static magnetic field source being sized and shaped to maneuver the probing space to overlap with an intra bone volume of the bone.

Abstract: A system for travelling wave MR imaging includes an MR imaging apparatus having a magnet coil assembly having a magnet coil bore extending therethrough, a gradient coil assembly positioned within the magnet coil bore and having a gradient coil bore extending therethrough, and a waveguide positioned within the gradient coil bore. The waveguide has a waveguide bore extending therethrough. A computer is programmed to access a scan sequence comprising an RF pulse sequence and execute the scan sequence. During execution of the scan sequence, the computer is programmed to operate the waveguide in a hybrid mode to transmit an RF pulse of the RF pulse scan sequence as a travelling wave at a frequency lower than a cutoff frequency of a principal mode of the waveguide absent a dielectric core and to acquire MR signals from an imaging subject positioned within the waveguide bore.

Abstract: In a magnetic resonance apparatus and operating method therefore, 3D navigator data are acquired and are used to correct spatially varying phase errors in contemporaneously acquired imaging data in each shot of a multi-shot data acquisition sequence. A mosaic sampling scheme is used to enter the diffusion-weighted magnetic resonance data and the navigator data into k-space respectively in blocks that each form a subset of the entirety of k-space. The navigator data in each shot are entered into a block that is located at the center of k-space, and, in each shot, the corresponding image data are entered into an offset block in k-space, that is offset in at least one spatial direction from the navigator data block. The offset is varied from shot-to-shot.

Abstract: In a magnetic resonance (MR) method and apparatus for spatially resolved determination of at least one MR parameter that influences an MR signal detected in an MR measurement of a region of an examination subject, first complex image data and second complex image data, respectively acquired with different acquisition coils and at different echo times in an echo imaging sequence, are provided to a processor. The different image data sets have complex image points that correspond with each other with regard to the imaged volume element of the examination subject. The MR parameter is determined in the processor for at least a portion of these image points by determination of an image point vector respectively for the first and second echo times and by combining the image point vectors to at least partially compensate echo time-independent phase or magnitude portions in the acquired image data.

Abstract: Apparatus for use in a magnetic resonance imaging system, the imaging system generating a magnetic imaging field in an imaging region (5), the apparatus including at least one coil for at least one of transmitting, receiving or transceiving an electromagnetic field, a field component (4) (such as a coil or a shield) and a drive (6) coupled to the field component for moving the field component (4) relative to the imaging region (5) to thereby modify the electromagnetic field during imaging process. The same concept can also be applied to nuclear imaging or nuclear spectroscopy apparatus.

Abstract: A magnetic resonance imaging (MRI) system and method uses an MRI gantry having a static magnet structure, controllable gradient magnet structures and at least one radio frequency (RF) coil for transmitting and receiving RF signals to and from an imaging volume. Control circuits are configured to control gradient magnetic fields generated by the gradient magnet structures, to transmit/receive RF signals to and from the at least one RF coil and to process RF signals received during a diagnostic MRI scan to produce displayable images of structures located within the imaging volume. The control circuits are configured to include a preparatory fat decoupling RF pulse as part of a patient ROI (region of interest) shimming sequence effected prior to a fat suppression type of diagnostic MRI data acquisition scan sequence.

Abstract: A transmit coil arrangement for a magnetic resonance device includes a plurality of individually actuatable conductor loops following one after another in a peripheral direction and a longitudinal direction on a cylinder surface. At least two groups, at a distance from one another in the peripheral direction, of at least two conductor loops following one after the other in the longitudinal direction are provided in the peripheral direction. To decouple the at least two groups, each of the at least two groups is bounded at least in the peripheral direction by at least one screen surface extending essentially in a radial direction and the longitudinal direction.

Abstract: In one aspect, an apparatus for performing chemical exchange saturation transfer (CEST) magnetic resonance imaging on a region of an object being imaged is provided.

Abstract: A method of performing nuclear magnetic resonance imaging of a body comprising at least two populations of nuclei characterized by different spin resonance frequencies, the method comprising the steps of: (a) immerging said body (B) in a static magnetic field (B0) for aligning nuclear spins along a magnetization axis; (b) exposing it to a transverse radio-frequency pulsed field (B1) for flipping said nuclear spins, said radio-frequency pulsed field comprising a train of elementary pulses, each having a constant frequency and amplitude, and a continuous phase; (c) detecting a signal emitted by nuclear spins excited by said radio-frequency pulsed field; characterized in that it also comprises, prior to performing steps (a)-(c), computing a set of optimal parameters (N, ?i, ?i, ?i) of said train of elementary pulses for minimizing the differences between the actual values of the spin-flip angles (FAj) of nuclei belonging to each of said populations and predetermined target values thereof; said predetermined targ

Abstract: A method of controlling the static magnetic field in an NMR spectrometer in such a way that the magnetic field can be homogenized even if there is a temperature gradient across a sample tube. A distribution of resonance frequencies and chemical shift differences within the sample tube is found by NMR measurements for each of two peaks of a calibration sample. A temperature distribution is found based on the distribution of the chemical shift differences. A distribution of chemical shifts of a solvent used for the measurements is found, based on the temperature distribution in the sample tube. Shimming is done using magnetic field gradients based on the distribution of the chemical shifts of the solvent.

Abstract: A method based on pure phase encode FIDs that permits high strength gradient measurement is disclosed. A small doped water phantom (1˜3 mm droplet, T1, T2, T2*<100 ?s) within a microprobe is excited by a series of closely spaced broadband RF pulses each followed by single FID point acquisition. Two trial gradient waveforms illustrate the technique, neither of which could be measured by the conventional microprobe measurement. The first is an extended duration gradient waveform while the other illustrates this method's ability to measure gradient waveforms with large net area and/or high amplitude. This method is a point monitor with simple implementation and low cost hardware requirements.