Abstract: A method for magnetic resonance imaging (MRI) a first volume and a second volume spaced apart from the first volume is provided. The first volume is excited with a first linearly varying phase with respect to k-space. The second volume is excited with a second linearly varying phase with respect to k-space, wherein the first linearly varying phase has a different slope than the second linearly varying phase. Data in k-space is acquired line by line. The acquired data in k-space is Fourier transformed to image space. An image is formed with a first volume image and a second volume image from the transformed data. Use of phase modulation allows imaging with a reduced field-of-view, which can result in faster scan times or improved performance of parallel imaging acquisition strategies.

Abstract: This invention relates to a method for improving the performance of a nuclear quadrupole resonance detection system by reducing, during reception, the coupling between one or more excitation coils that provide a radio frequency magnetic field that excites quadrupole nuclei, and one or more high temperature superconductor receive coils that detect the resulting nuclear quadrupole resonance signal.

Abstract: An apparatus for producing a nuclear spin-polarized noble gas by spin-polarizing a noble gas in the presence of an optical pumping catalyst under application of magnetic field and laser light, including a cell having a thin reaction chamber, a gas introduction conduit connected in fluid communication with the reaction chamber for feeding the noble gas, a gas discharge conduit connected in fluid communication with the reaction chamber, a first gate valve having an outlet port connected to the gas introduction conduit and an inlet port adapted to be in fluid communication with a noble gas introduction line, a second gate valve having an inlet port connected to the gas discharge conduit and an outlet port, and a capillary tube removably connected to the outlet port of the second valve for recovering a nuclear spin-polarized noble gas produced in the reaction chamber. The apparatus may be directly connected to NMR or MRI.

Abstract: Methods of, and systems for, simultaneously compensating for external-magnetic-field inhomogeneity as well as radiofrequency magnetic-field inhomogeneity in an MRI system. In one method embodiment, a pulse sequence is applied when the transmitter-reference frequency is delivered on resonance. The pulse sequence includes radiofrequency pulses which may be applied at arbitrary-excitation-flip angles that are not necessarily 90° degrees. The pulse sequence also includes spin-locking pulses applied in concert with a refocusing-composite pulse. In another method embodiment, a pulse sequence is applied when the transmitter-reference frequency is delivered off resonance. This off-resonance-pulse sequence includes radiofrequency pulses which may be applied at arbitrary-excitation-flip angles that are not necessarily 90° degrees. Sandwiched between the excitation-flip angles are at least two off-resonance-spin-lock pulses applied at an inverse phase and frequency from each other.

Abstract: A magnetic resonance imaging (MRI) pulse employed in MRI devices and methods that increase the signal-to-noise ratio, allowing thinner slice thicknesses, and allowing more contiguous slices. In an MRI device, a patient is subjected to a constant magnetic field, and then RF pulses are used to excite the atoms in the body of the patient. The atoms release a corresponding RF signal when the atoms relax, which can be measured and mapped into a visual display. The RF pulses used to excite the atoms in the body of the patient use a modified Bessel function. The Bessel function having an approximately rectangular waveform in the frequency domain increases the signal-to-noise ratio, allows thinner slice thicknesses, and allowed more contiguous slices, resulting in a better MR image and a more efficient MRI apparatus.

Abstract: A system and method are provided for designing RF pulses which have improved magnetization profiles. By utilizing an optimal control approach as an alternative to, or in combination with, non-iterative approximations, RF pulses generated by the system and method described herein will exhibit less deviation from that of “ideal” Bloch solutions. Consequently, the magnetization profiles produced by the RF pulses generated by the system and method described herein will be closer to the desired profiles. In addition, limitations of non-iterative approximations, such as maximum tip angle limits and linearity constraints, can be avoided.

Abstract: A magnetic resonance imaging apparatus includes a unit which generates a diffusion weighted image based on a magnetic resonance signal from an object, a unit which calculates an apparent diffusion coefficient based on the diffusion weighted image, and a processing unit which subjects the diffusion weighted image to a process of indicating a region having the apparent diffusion coefficient of less than a threshold value with a highlight in contrast with other region.

Abstract: When a magnetic resonance signal is received more than once, while a table (transfer unit) is moved, a gradient magnetic field is applied in the table moving direction, and an application amount (intensity and application time) of the gradient magnetic field in the table moving direction is changed every acquisition of data. As for the encoding by the gradient magnetic field in the table moving direction, a series of phase encode is performed at different positions of an examination target, unlike a conventional phase encode. Therefore, the Fourier transform cannot be applied to the image reconstruction. Given this situation, a magnetization map of total FOV of the examination target is determined in such a manner that a sum of the square of an absolute value of a difference is minimized, the difference between a received signal and a signal calculated from the magnetization map set as a variable, and then, the reconstruction is performed.

Abstract: A method and circuit arrangement for operating multi-channel transmit/receive antenna devices or arrangements is used in magnetic resonance imaging (MRI) systems. Full independent control of complete multi-channel RF transmit and receive chains can be conducted in a flexible way and new options like RF shimming, transmit sensitivity encoding (TransmitSENSE), RF encoding, determination of S- or Z-matrix prior to spin echo measurements, calibration, SAR (specific absorption rate) reduction etc. can be utilized or improved.

Abstract: Apparatus for performing magnetic resonance imaging are disclosed. In one aspect coil antennas for use with a horizontal field magnetic resonance imaging apparatus are placed in proximity to the scanning region to obtain magnetic resonance images. The coils are arranged in quadrature geometry and housed in a planar structure.

Abstract: A coils array (40, 40?) including a plurality of coils (71, 72, 73) receives magnetic resonance signals from an examination region of a magnetic resonance imaging scanner (10). Each coil has mixing circuitry (74, 75, 76, 80, 81, 82) that frequency-shifts the received magnetic resonance signal to a selected transmission channel frequency. The coils array further includes combining circuitry (90) that combines the frequency-shifted magnetic resonance signals to produce an analog frequency domain multiplexed transmission signal output of the coils array. Receiver electronics (56, 56?) receive the analog frequency domain multiplexed transmission signal from the coils array.

Abstract: To reduce high SAR values in the field of magnetic resonance imaging, and particularly with a whole body coil assembly for an MRI apparatus, at least a bracket is added between the supporting tube of a whole body coil assembly and the connecting copper sheet in order to radially raise the connecting copper sheet and the capacitors away from the human body. In addition to effectively solving the problem of a high SAR value, at the same time no significant loss of the imaging performance occurs. Moreover, the structure is simple, so the costs of modification or production are low.

Abstract: A low temperature probe having a coil used in an NMR apparatus includes an opposed heat exchanger cooling a cooling medium, and a cooling apparatus having a first cooling stage capable of cooling to no more than 10K and a second cooling stage capable of cooling to at least 10K in series cooling the cooling medium from the opposed heat exchanger. A probe portion has a first heat exchanging portion executing heat exchange between the cooling medium and the coil, a circulation structure which circulates the cooling medium into the opposed heat exchanger, a second heat exchanging portion executing heat exchange between the cooling medium and a heat radiation shield. The heat radiation shield has a heat capacity greater than the heat capacity of the cooling medium.

Abstract: An apparatus for use in a magnetic resonance (MR) system, which generates an external MR magnetic field, is provided. A rotor comprises a rotor shaft with an axis along a length of the rotor shaft and a plurality of coils on the rotor shaft. A housing supports and surrounds the rotor, where a part of the housing surrounds sides of the rotor and where the part of the housing surrounding sides of the rotor is magnet free. A mount allows for the mounting of the housing to the MR system in a location where the MR system provides a magnetic field, wherein a component of the MR magnetic field that is perpendicular to the axis of the rotor shaft is at least 100 Gauss. An active timer applies a voltage to the plurality of coils with alternating polarity. Contacts provide an electrical connection between the active timer and the plurality of coils.

Abstract: Data is collected for average units including acquisition of template data and acquisition of imaging data. A frequency difference is calculated between a resonant frequency in a reference average unit and a resonant frequency of an object average unit based on phase variation of the magnetic field between the reference average unit and the object average unit. Corrected phase shift is produced in image data collected in one or more average units based on the frequency difference. An image is reconstructed based on the imaging data collected in the reference average unit and corrected imaging data concerning the object average unit constituted by one or more average units.

Abstract: A magnetic resonance imaging apparatus has a static field magnet, gradient coils, a gantry including an opening and storing the static field magnet the gradient coils, a bed structure for advancing and retreating a table-top, on which an object can be placed, with respect to the opening, a lower coil formed by a radio frequency coil disposed below the table-top, and a movement control unit configured to control the lower coil to be movable.

Abstract: A method and apparatus for ferrous object and/or magnetic field detection are provided. Embodiments can improve magnetic resonance imaging (MRI) safety and increase the safety of MRI facilities. Embodiments can detect a given magnetic field strength around a MRI machine and alert users to the field's presence. In an embodiment, the magnetic field warning system can rely on a single badge that warns its user. In another embodiment, the badge can utilize an RFID system. The RFID system can turn the badge on when it enters the MRI room and off when it leaves the MRI room. In another embodiment, a badge with a rechargeable battery and charger can be utilized with or without an RFID tag. The subject badges or other detection devices can be worn by a person, located on or near a ferrous object, embedded in clothing, or located in other positions convenient to a user.

Abstract: A local coil arrangement for magnetic resonance applications has an acquisition coil for acquisition of a magnetic resonance signal excited in an examination subject by means of a transmission coil; and a transponder. The transponder is coupled to the acquisition coil such that it can be fed with electrical energy via the acquisition coil The transponder is fashioned to send a transponder signal on a transponder frequency when and as soon as an excitation signal induced in the acquisition coil by means of the transmission coil exceeds a threshold. When the control device receives the transponder signal, it adjusts the further operation of the transmission antenna or operates it only with reduced power.

Abstract: A RF transmit coil decoupling circuit in a parallel drive configuration comprises a power amplifier and an output matching network to shim the B1 field in response to inhomogeneities therein. The separate coil segments in a transmit array are effectively decoupled from each other despite inherent mutual inductance between coil segments by the decoupling circuit. The output matching network forms a high impedance block seen by the coil elements, while it provides a load line impedance at the output of the power amplifier. The transmission line transformer in the output matching network suppresses higher order harmonics for clearer RF wave forms. It also dampen the Q factor of the output matching network allowing stable operation with a series tuned coil element.

Abstract: A method for magnetic resonance imaging (MRI) is provided. A magnetic resonance excitation is provided. A magnetic field is read out through k-space using winders, wherein some of the winders overlap for a length of the winders. Readout data from overlapping lengths of winders is used to estimate motion. The readout may use a two dimensional discrete Fourier transform acquisition.