Abstract: Active resistive shim coil assemblies may be used in magnetic resonance imaging (MRI) systems to reduce in-homogeneity of the magnetic field in the imaging volume. Disclosed embodiments may be used with continuous systems, gapped cylindrical systems, or vertically gapped systems. Disclosed embodiments may also be used with an open MRI system and can be used with an instrument placed in the gap of the MRI system. An exemplary embodiment of the active resistive shim coil assembly of the present disclosure includes active resistive shim coils each operable to be energized by separate currents through a plurality of power channels. In some embodiments, the disclosed active resistive shim coil assemblies allow for various degrees of freedom to shim out field in-homogeneity.

Abstract: Systems and methods for correcting phase errors in chemical shift encoded data are described. The technique is self-calibrated, without the need for specialized calibration data, and therefore may enable fat and iron quantification using data from clinical and research sites that do not have specialized pulse sequences.

Abstract: A circuit arrangement for an MRT system and a method for operating an MRT system are disclosed. The circuit arrangement includes a gradient amplifier having a switch-mode output stage, a regulator device, and a modulator connected therebetween in the circuit. To ensure patient safety, a control path is integrated into a drive path of the circuit arrangement or the MRT system provided for driving a gradient coil, the gradient coil being connected to an output of the switch-mode output stage. The control path includes a limiter stage connected downstream of the regulator device, the modulator, the switch-mode output stage and its supply voltage. The limiter stage is connected in the circuit between the regulator device and an input of the modulator, to limit a control signal output by the regulator device and limit the voltage for the gradient coil provided by the switch-mode output stage at its output.

Abstract: Various embodiments include a method for determining a viscosity for heavy oil in a formation by obtaining viscosity data and nuclear magnetic resonance (NMR) relaxation time distribution data for a plurality of oil samples. A correlation is determined between a set of viscosity data for the plurality of oil samples and an NMR relaxation time geometric mean for the plurality of oil samples. An NMR relaxation time geometric mean intrinsic value is determined based on the correlation, apparent hydrogen index, and TE. Electromagnetic energy may then be transmitted into a formation and NMR relaxation time distributions determined for oil in the formation based on secondary electromagnetic field responses associated with the electromagnetic energy. A viscosity of the oil in the formation may then be determined based a correlation between the set of viscosity data and the NMR relaxation time geometric mean intrinsic value of the distribution data.

Abstract: A fastening system for attaching an NMR probe to an NMR magnet includes a discoid insert and a retention system that is rigidly connected to the magnet and on which the insert can be mounted. A form-fitting, variable-force connection is established between the NMR probe and the retention system using a spring element. The probe attaches to the insert by a plurality of integral, rigid retaining elements that are of an invariable fixed length. The spring element and the retaining elements are designed geometrically such that in a first, opened state the connection between the insert and the retaining elements has a mechanical backlash between 0.5 mm and 5 mm when the spring element is relaxed. In a second, closed state the connection between the insert and the retaining elements has no mechanical backlash when the spring element is under mechanical tension.

Abstract: A phase actuator for a continuously adjustable phase displacement at a first frequency is provided. The phase actuator has a first inductance with tapping point, a first continuously variable capacitor, and a transformation network. A signal input and a signal output of the phase shifter are connected by the first inductance. The first continuously adjustable capacitor is connected in parallel to the first inductance. The tapping point is connected via a transformation network to a reference mass, where an impedance value of the transformation network corresponds to a quarter wave transform of a capacitance value of the first continuously variable capacitance at the first frequency.

Abstract: There is provided a Nuclear Magnetic Resonance (NMR) measurement cell for use with a solution enabling the introduction of a gas into said solution. The measurement cell includes at least a detection volume designed to be installed in a static magnetic field of an NMR spectrometer, and includes in said detection volume, a gas introduction zone, a measurement chamber for the solution at a distance from the gas introduction zone and a network of conduits for the solution formed to set up fluid communication between the gas introduction zone and the measurement chamber. The gas introduction zone includes at least one gas inlet in the network of conduits, to generate bubbles in the gas introduction zone only. There is also provided a method of manufacturing such a measurement cell and a measurement assembly including such a measurement cell.

Abstract: In one aspect, the disclosure relates to a nuclear magnetic resonance transceiver including: (a) a variable-frequency electromagnetic signal generator with (i) a frequency input and (ii) an EM signal output; (b) an electronic frequency controller including (i) a frequency output coupled to the frequency input of the variable-frequency EM signal generator, (ii) an intermediate frequency set-point input, and (iii) an intermediate frequency measurement input; (c) an NMR transmission probe with an EM signal input coupled to the EM signal output of the variable-frequency EM signal generator; (d) an NMR receiving probe with an EM signal output; and (e) an electronic mixer with (i) a first input coupled to the EM signal output of the NMR receiving probe, (ii) a second input coupled to the EM signal output of the variable-frequency EM signal generator, and (iii) a mixed EM signal output coupled to the frequency measurement input of the frequency controller.

Abstract: A portable magnetic resonance imaging (“MRI”) system that uses static magnetic field inhomogeneities in the main magnet for encoding the spatial location of nuclear spins is provided. Also provided is a spatial-encoding scheme for a low-field, low-power consumption, light-weight, and easily transportable MRI system. In general, the portable MRI system spatially encodes images using spatial inhomogeneities in the polarizing magnetic field rather than using gradient fields. Thus, an inhomogeneous static field is used to polarize, readout, and encode an image of the object. To provide spatial encoding, the magnet is rotated around the object to generate a number of differently encoded measurements. An image is then reconstructed by solving for the object most consistent with the data.

Abstract: The present invention is directed to a system and method for magnetic resonance imaging including an extended Fourier transform-based velocity-selective pulse train design with a pair of refocusing pulses within each velocity encoding step and accompanying phase cycling between different velocity encoding steps. The present invention is robust to B0/B1 field inhomogeneity and eddy current effects. The utility of this technique, through a velocity-selective inversion pulse, is demonstrated in a 2D velocity-selective arterials spin labeling study, which shows a reasonable agreement in CBF quantification with the standard PCASL method.

Abstract: A method of acquiring magnetic resonance imaging (MRI) data of a subject includes dividing a region of interest into a plurality of slices, and acquiring the slices using an iterative process that interleaves acquisition of shim data covering the plurality of slices with acquisition of image data covering the slices over a plurality of iterations.

Abstract: In a method and apparatus for correction of magnetic resonance image data, at least on environmental conditions map is provided to a computer, measurement data are acquired using a prospective correction method and storage of a first set of correction data, established within the framework of the prospective correction method, is stored. Image data are reconstructed from the recorded measurement data, and a second set of correction data are determined for the created image data and/or the recorded measurement data by a second correction method on the basis of the environmental conditions map and on the basis of the first set of correction data. Corrected image data are generated using the second set of correction data.

Abstract: The method and apparatus for the acquisition of scan data of an examination object by execution of a magnetic resonance scanning protocol having at least one suppression module, a relevant volume in the examination object is determined in which the magnetization of the examination object to be examined is to be manipulated and/or the scan data are to be acquired. For each suppression module contained in the scanning protocol, the associated suppression volume in which signals are to be suppressed is determined. The relevant volume that has been determined is optimized by taking account of the determined suppression volumes. Optimized scanning parameters of the scanning protocol are determined such that the best possible scanning conditions prevail in the optimized relevant volume. The scanning protocol is executed as a scanner with the optimized scanning parameters determined and the scan data acquired thereby are made available as a data file.

Abstract: A magnetic resonance imaging apparatus according to an embodiment includes a sequence control unit, an image generating unit, and a deriving unit. The sequence control unit executes first imaging scan for acquiring data of a range including a target internal organ and second imaging scan for acquiring data for a diagnostic image by controlling execution of a pulse sequence. The image generating unit generates an image by using data acquired by the first imaging scan. The deriving unit derives an imaging scan area in which data for the diagnostic image are acquired in the second imaging scan and a related area set associated with the imaging scan area in the second imaging scan, based on image processing using the image.

Abstract: A method for determining a position of an RF coil in a magnetic resonance imaging (MRI) system is disclosed. As an example, a center of a field of view (FOV) to be scanned may be adjusted to a magnetic field center of an MRI system, and coordinate values in a coordinate system for shape-characteristic points of the FOV may be determined, where an origin of the coordinate system is located at the magnetic field center of the MRI system. A preset gradient magnetic field may be applied to the FOV, and coil units respectively covering the shape-characteristic points may be determined. An effective region may be obtained by connecting the determined coil units according to the shape of the FOV, and a coil unit located in the effective region may be determined as an effective coil unit for imaging the FOV by the MRI system.

Abstract: The present invention is directed to a system and method for measuring blood volume using non-contrast-enhanced magnetic resonance imaging. The method of the present invention includes a subtraction-based method using a pair of acquisitions immediately following velocity-sensitized pulse trains for the label module and its corresponding control module, respectively. The signal of static tissue is canceled out and the difference signal comes from the flowing blood compartment above a cutoff velocity. After normalizing to a proton density-weighted image acquired separately and scaled with the blood T1 and T2 relaxation factors, quantitative measurement of blood volume is then obtained.

Abstract: Provided is a magnetic resonance measuring apparatus that records measurement data measured by MRS or the like and a periodic motion of the measurement object during the measurement of the measurement data in association with each other, and classifies spectra calculated from the measurement data in accordance with a time phase of the periodic motion. Created spectra are integrated for each classification to thereby create partially integrated spectra, correction based on a relationship between the periodic motion and a phase fluctuation or a frequency fluctuation is performed on the partially integrated spectra, and the corrected partially integrated spectra are synthesized.

Abstract: A power electronic unit for an amplifier of an imaging magnetic resonance tomography (MRT) system is provided. The power electronic unit includes at least one printed circuit board, on which a plurality of transistors are arranged. Ports (e.g., drain and source) of the plurality of transistors are connected together by electrically conductive connections, and the plurality of transistors are all arranged on one side of the at least one printed circuit board. An output line or cable parallel to the connections, at least in sections, runs on the opposing side of the printed circuit board and may be connected or is connected with or without further interconnected elements (e.g., a balun) to transmitting coils of the MRT.

Abstract: Described here are systems and methods for using excited slice profiles to improve the point spread function (“PSF”) of super-resolution slices in SLIDER acquisitions while preserving all of the advantages of the SLIDER technique. The techniques described here may generally be referred to as “Generalized SLIDER” (“g-SLIDER”).

Abstract: A passive apparatus including a plurality of resonators increases signal-to-noise ratio of radiofrequency signals emitted by a specimen and captured by an MRI machine. The apparatus increases the magnetic field component of radiofrequency energy during signal transmission from the MRI machine to the specimen, and/or reception of signals from the specimen to the MRI machine. Moreover, the apparatus enhances specimen safety by substantially avoiding unwanted generation of an electric field, or an increase in the electric field component of the RF energy. Use of the apparatus improves the images generated by the MRI machine, and/or reduces the time necessary for the MRI machine to capture the image.