A method for NMR measurements on borehole materials, e.g., sidewall cores, is based on performing a standard measurement in substantially homogeneous magnetic fields with a sensitivity volume covering an entire sample and a measurement on a fragment of the sample (local measurement), the fragment having a predetermined volume independent of the irregularities of the sample shape (e.g., irregular shaped edges). The fragment of the sample is selected using a switchable static magnetic field gradient or a localized radio-frequency magnetic field. The homogeneous and the local measurement data are processed jointly to obtain volume normalized NMR relaxation data (in porosity units), the processing also using a calibration sample data. A measurement apparatus with an automated sample transfer can be used to implement the method in order to perform high-throughput NMR relaxation measurements that do not require independent measurement of the sample volume.

The present disclosure relates to systems and methods for magnetic resonance imaging (MRI). The systems may include a gradient coil assembly configured to form a gradient magnetic field. The systems may also include a cryostat including a superconducting coil assembly and a magnetic field shielding apparatus arranged on/in a component of the cryostat. The superconducting coil assembly may be configured to form a main magnetic field. The magnetic field shielding apparatus may be configured to shield the superconducting coil assembly from a stray field of the gradient coil assembly. The magnetic field shielding apparatus may include a conductive shielding component, a shielding cylinder, or a combination thereof.

The present disclosure relates to systems and methods for magnetic resonance imaging (MRI). The systems may include a gradient coil assembly configured to form a gradient magnetic field. The systems may also include a cryostat including a superconducting coil assembly and a magnetic field shielding apparatus arranged on/in a component of the cryostat. The superconducting coil assembly may be configured to form a main magnetic field. The magnetic field shielding apparatus may be configured to shield the superconducting coil assembly from a stray field of the gradient coil assembly. The magnetic field shielding apparatus may include a conductive shielding component, a shielding cylinder, or a combination thereof.

A method for temperature quantification using magnetic resonance fingerprinting (MRF) includes acquiring MRF data from a region of interest in a subject using an MRF pulse sequence with smoothly varying RF phase for MR resonant frequencies that is played out continuously. For each of a plurality of time intervals during acquisition of the MRF data the method further includes comparing a set of the MRF data associated with the time interval to an MRF dictionary to determine at least one quantitative parameter of the acquired MRF data, determining a temperature change based on the at least one quantitative parameter and generating a quantitative map of the temperature change in the region of interest. The region of interest can include aqueous and adipose tissue.

A method for temperature quantification using magnetic resonance fingerprinting (MRF) includes acquiring MRF data from a region of interest in a subject using an MRF pulse sequence with smoothly varying RF phase for MR resonant frequencies that is played out continuously. For each of a plurality of time intervals during acquisition of the MRF data the method further includes comparing a set of the MRF data associated with the time interval to an MRF dictionary to determine at least one quantitative parameter of the acquired MRF data, determining a temperature change based on the at least one quantitative parameter and generating a quantitative map of the temperature change in the region of interest. The region of interest can include aqueous and adipose tissue.

An ambulance-compatible magnetic resonance imaging (MRI) system for on-site emergency diagnosis includes a mid-field super-conducting head-only magnet including a bore and an active shield arranged relative to the magnet, a passive shield arranged relative to the magnet, the passive shield including a first flange arranged adjacent to a first side of the magnet bore, a second flange arranged adjacent to a second side of the magnet bore, wherein the first flange and the second flange are electrically connected to each other, and wherein the passive shield is operative to capture flux extending out from the magnet bore and return the flux to the magnet. An asymmetric head gradient assembly for generating magnetic gradient field in the mid-field super-conducting magnet is also provided, the magnetic gradient field being between 100-150 mT/m or having a slew rate between 400-800 T/m/s. The MRI system includes a receiver coil and a controller operatively coupled to the receive coil, the controller configured to produce an image based on data obtained from the receive coil. The MRI system is mountable in an ambulance vehicle.

A magnetic resonance imaging apparatus according to an embodiment includes a static magnetic field magnet, a plurality of radio frequency coils, and processing circuitry. The static magnetic field magnet generates a static magnetic field having a magnetic field strength that changes spatially. The plurality of radio frequency coils receive a nuclear magnetic resonance signal generated from a subject by an influence of a radio frequency pulse transmitted to the subject, the subject being placed in the static magnetic field having a magnetic field strength that changes spatially. The processing circuitry controls each of the plurality of radio frequency coils to receive the nuclear magnetic resonance signal at each of a plurality of frequencies tuned according to at least a distribution of the static magnetic field.

A magnetic resonance imaging apparatus according to an embodiment includes a static magnetic field magnet, a plurality of radio frequency coils, and processing circuitry. The static magnetic field magnet generates a static magnetic field having a magnetic field strength that changes spatially. The plurality of radio frequency coils receive a nuclear magnetic resonance signal generated from a subject by an influence of a radio frequency pulse transmitted to the subject, the subject being placed in the static magnetic field having a magnetic field strength that changes spatially. The processing circuitry controls each of the plurality of radio frequency coils to receive the nuclear magnetic resonance signal at each of a plurality of frequencies tuned according to at least a distribution of the static magnetic field.

Techniques for suppressing noise in an environment of a magnetic resonance (MR) imaging system having at least one primary coil and at least one auxiliary sensor. The techniques involve estimating a transform, that, when applied to noise received by the at least one auxiliary sensor, provides an estimate of noise received by the at least one primary coil. The transform is estimated from data obtained by the at least one primary coil and the least one auxiliary sensor, with the data being weighted prior to estimation to remove or suppress data in regions with a high signal to noise ratio. In turn, the estimated transform may be applied to noise measured by the at least one auxiliary sensor during imaging of a patient, to estimate and suppress noise present in the MR signals received by the at least one primary coil during imaging.

A location pad includes multiple field-generators and a frame. The multiple field-generators are configured to generate respective magnetic fields in a region-of-interest of a patient organ, so as to measure a position of a medical instrument in the region-of-interest. The frame is transparent to an X-ray radiation, and is configured to fix the multiple field-generators at respective positions surrounding the region-of-interest.