Abstract: A magnetometer for use with a sample including an atomic vapor includes a cell containing the sample such as a multipass cell including a first mirror element and a second mirror element configured so that an incoming light beam injected into the container will reflect multiple times between the first mirror element and the second mirror element. A polarized pump light source is configured to transmit pump light through the cell and pump the sample. A polarized probe light source configured to transmit probe light through the cell and probe the sample. A detector configured to detect a polarization angle or intensity of the probe light transmitted through the sample. A processor may be configured to calculate a precession frequency of the sample based on a first probe light pulse and a frequency correction based on a second probe light pulse.

Abstract: A flipped fitting method that performs a flipped curve fitting on a maximum of 256 MRI images obtained at different echo times using an EPI image which obtains a plurality of MRI images at a plurality of different echo times within a TR period after application of an excitation RF pulse. Then, T2* values are fitted based on a sufficient amount of acquired TE images, such that it is possible to provide much more accurate T2* values than these provided by underestimated or overestimated fitting by the existing method which is based on only 12 images and to obtain rapid and accurate data without nerve stimulation or acoustic noise. Further, the flipped fitting method is more suitable and accurate for showing the real T2* values.

Abstract: A method of performing spatially localized magnetic resonance spectroscopy includes receiving a magnetic resonance image of an object; identifying a plurality C of compartments that generate magnetic resonance spectroscopy signals in the object including at least one compartment of interest; segmenting in at least one spatial dimension the magnetic resonance image of the object into the C compartments; acquiring magnetic resonance spectroscopy signals from the compartments by applying a plurality of M? phase encodings applied in the at least one spatial dimension, wherein M??C; calculating a spatially localized magnetic resonance chemical shift spectrum from the at least one compartment of interest; and rendering a spatially localized magnetic resonance spectrum that is substantially equal to a spatial average of magnetic resonance chemical shift spectra from the at least one compartment of interest. A magnetic resonance spectroscopy and imaging system is configured to perform the above method.

Abstract: Apparatus, methods, and other embodiments associated with NMR fingerprinting are described. One example NMR apparatus includes an NMR logic that repetitively and variably samples a (k, t, E) space associated with an object to acquire a set of NMR signals that are associated with different points in the (k, t, E) space. Sampling is performed with t and/or E varying in a non-constant way. The varying parameters may include flip angle, echo time, RF amplitude, and other parameters. The NMR apparatus may also include a signal logic that produces an NMR signal evolution from the NMR signals, and a characterization logic that characterizes a resonant species in the object as a result of comparing acquired signals to reference signals. The reference signals may be stored in a dictionary. Singular value decomposition may be applied to the dictionary and the acquired signals before comparing the acquired signals to the reference signals.

Abstract: A method is disclosed for recording a parameter map of a target region via a magnetic resonance device. In at least one embodiment, an optimization method is used for the iterative reconstruction of the parameter map. In the optimization method, the deviation of undersampled magnetic resonance data of the target region present in the k-space for different echo times, magnetic resonance data of a portion of the k-space being present in each case for each echo time, is assessed from hypothesis data of a current hypothesis for the parameter map obtained as a function of the parameter from a model for the magnetization. To determine the magnetic resonance data of a portion of the k-space, undersampled raw data is initially acquired within the portions by way of the magnetic resonance device embodied for parallel imaging, and missing magnetic resonance data within the portions is completed by way of interpolation.

Abstract: A magnetic resonance imaging apparatus is provided. The apparatus includes a plurality of receiving antennas for receiving a plurality of reception signals. The apparatus also includes at least one first superposition device having at least one first and one second output, which in each case serve for providing a mode formed by superposition of at least two of the reception signals. The apparatus also includes at least one first frequency division multiplex device for transmitting input signal present at a first and a second input of the frequency division multiplex device via a first transmission link on different frequency bands to a receiving unit, wherein the first output of the first superposition device is connected to the first input of the first frequency division multiplex device and the second output of the first superposition device is connected directly or indirectly to a second transmission link.

Abstract: Apparatuses and methods for sensing rotations are provided. One embodiment of the apparatus includes a cell containing alkali and active nuclear magnetic resonance (NMR) isotope(s) atoms, a magnet providing a first magnetic field, a light source, and optics which circularly polarize light to generate a pump beam for optically pumping the alkali atoms and, together with a second magnetic field orthogonal to the first magnetic field or a modulation of the light, causing the alkali and the NMR isotope atoms to precess about the first magnetic field. The apparatus further includes a partial reflector opposite the light source and configured to, in conjunction with a first linear polarizer, generate a reflected linearly-polarized probe beam from a portion of the pump beam, and one or more polarizing beam splitters configured to split light of the probe beam incident thereon into orthogonally polarized components that are detected and used to determine rotations.

Abstract: Provided is a low magnetic field and ultra-low magnetic field NMR and MRI apparatus. The low magnetic field and ultra-low magnetic field NMR and MRI apparatus includes a SQUID sensor and a prepolarization magnetic field coil. The prepolarization magnetic field coil generates a prepolarization magnetic field to polarize a sample. The prepolarization magnetic coil generates a counter pulse in a direction opposite to that of the prepolarization magnetic field immediately before or immediately after the prepolarization magnetic field is generated. The counter pulse demagnetizes wanted magnetization including that of the prepolarization magnetic field coil itself.

Abstract: A system and method for generating magnetic resonance imaging (MRI) images is provided. The MRI system is directed to perform the dynamic contrast enhanced imaging study of the subject by exciting a two-dimensional (2D) slice within a portion of a field of view (FOV) of the MRI system and acquiring imaging data from the 2D slice by sampling k-space in a pseudorandom manner using sampling trajectories extending between a center of k-space and peripheral areas of k-space. Thereafter, the 2D slice is slid to another portion of the FOV at a velocity selected to be greater a velocity of the motion of the subject and the process is repeated for each of a plurality of 2D slices to create images of the subject where artifacts induced by the motion of the subject are reflected as geometric distortions.

Abstract: To obtain the irradiation magnetic field distribution of each channel of a multichannel transmission RF coil at high speed, for multiple channels which are all or some of the channels of the transmission coil, an image is acquired by irradiation with one channel or a combination of two or more channels, an irradiation magnetic field distribution upon irradiation with all of the multiple channels is acquired, and the irradiation magnetic field distribution of each channel is calculated using the acquired irradiation magnetic field distribution of all of the multiple channels and the phase difference calculated from the image of each channel and the image of all of the multiple channels.

Abstract: The embodiments relate to a magnetic resonance scanner including an antenna system having an adjustment device for modifying the natural frequency of a natural mechanical oscillation mode of the antenna system. According to the embodiments, in a method for operating a magnetic resonance imaging system having a magnetic resonance scanner comprising an antenna system, a natural frequency of a natural mechanical oscillation mode of the antenna system is controlled and/or regulated.

Abstract: The present invention provides a multi-azimuth nuclear magnetic resonance logging instrument and an antenna excitation method, the nuclear magnetic resonance logging instrument includes: a probe framework and a shielding layer arranged in the probe framework; a plurality of main magnets are provided above and below the shielding layer, respectively; central axes of the main magnets are parallel with each other, and distances between the central axes of each of the main magnets and a central axis of the probe framework are the same; a distance between central axes of any two main magnets is not smaller than a first preset value; and an antenna is provided at outer side of each main magnet, and a plurality of the antennas are fed independently. In the present invention, circumferential recognizing capability of the nuclear magnetic resonance logging instrument can be improved and three-dimensional (radial, axial and circumferential) stratum detection can be achieved.

Abstract: A method for emitting a sequence of high frequency pulses that may have different envelopes in a magnetic resonance tomography system is provided. A digital instruction signal that specifies the envelope for the high frequency pulses that are to be emitted is received. A digital control signal is transmitted to a high frequency unit for generating high frequency pulses, depending on the instruction signal. A test signal that allows notification of a current overload situation is received. The current control signal is reduced if the test signal indicates an overload situation.

Abstract: Nuclear magnetic resonance (NMR) gas isotherm techniques to evaluate wettability of porous media, such as hydrocarbon reservoir rock, can include constructing a NMR gas isotherm curve for a porous media sample gas adsorption under various pressures. A hydrophobic or hydrophilic nature of the porous media sample can be determined using the NMR gas isotherm curves. A wettability of the porous media sample can be determined based on the NMR gas isotherm curve. The wettability can be determined for porous media samples with different pore sizes. In the case of reservoir rock samples, the determined wettability can be used, among other things, to model the hydrocarbon reservoir that includes such rock samples, to simulate fluid flow through such reservoirs, or to model enhanced hydrocarbon recovery from such reservoirs.

Abstract: Gradient coil assemblies for horizontal magnetic resonance imaging systems (MRIs) and methods of their manufacture. Some embodiments may be used with open MRIs and can be used with an instrument placed in the gap of the MRI. In general, concentrations of conductors or radially oriented conductors may be moved away from the gap of the MRI so as to reduce eddy currents that may be induced in any instrument placed within the gap. Systems for directly cooling primary gradient and shield coils may be utilized and various coil supporting structures may be used to assist in coil alignment or to facilitate use of an instrument in the MRI gap.

Abstract: A method of investigating an object using nuclear magnetic resonance (NMR) equipment includes generating a one-dimensional projection of the object for each of a plurality of echoes utilizing echo train signal indications resulting from pulse sequences, and utilizing the plurality of one-dimensional projections, for each of the plurality of echoes, generating NMR image data for at least one location in the object. The NMR image data may be displayed. The displayed data may include a T2 decay curve, a T2 value display, a T2 distribution graph, or petrophysical data for at least one object location.

Abstract: In a method for acquiring MR diffusion data, in a control computer of an MRI system, multiple individual data sets, respectively corresponding to multiple diffusion models, are defined and combined to form a combined data set. Each of said individual data sets is comprised of multiple diffusion image individual data subsets that are to be acquired on one or more specific shells, respectively, and in one or more gradient directions, respectively. Different specific shells among the multiple shells have different diffusion factors. The control computer then operates the MRI system, namely the data acquisition scanner thereof, in order to acquire MR data corresponding to the defined combined data set.

Abstract: In one embodiment a magnetic resonance imaging method is disclosed. The method includes the steps of selecting a first RF pulse, selecting a second RF pulse, selecting one of the first RF pulse and the second RF pulse to be spatially selective, with the other being non-spatially selective, selecting a frequency of the first RF pulse to be the same or different than a frequency of the second RF pulse, applying the first RF pulse to excite a first portion of an object, applying the second RF pulse, forming at least one echo in the first portion of the object, obtaining signal data from the first portion of the object in response to the first RF pulse and the second RF pulse and reconstructing the obtained signal data from the first portion to form an image.

Abstract: A receiver of a magnetic resonance imaging system and a magnetic resonance imaging system are provided. The receiver includes a receiving end for receiving an analog magnetic resonance signal from a local coil of the magnetic resonance imaging system, a sending end for sending a digital magnetic resonance signal to an image reconstruction apparatus of the magnetic resonance imaging system, at least two digital processing channels connected to the sending end for digitizing the analog magnetic resonance signal to the digital magnetic resonance signal, and a channel selection unit connected between the digital processing channels and the receiving end for selecting a corresponding digital processing channel from the digital processing channels according to type information about the local coil. The embodiments may be compatible with many types of local coils without re-designing the local coils, which significantly reduces the cost of the system.

Abstract: A nuclear magnetic resonance (NMR) apparatus includes a transmitting assembly configured to emit one or more dual-wait-time pulse sequences, and a receiving assembly configured to detect a long-wait-time echo train and a short-wait-time echo train. The apparatus also includes a processor configured to perform at least one of: estimating a difference between the long-wait-time echo train and the short-wait-time echo train to generate a differential echo-train, inverting the differential echo-train into a differential T2 distribution, and detecting a motion artefact in response to determining that the differential echo-train includes a short-T2 porosity fraction that is greater than a threshold value; and inverting two echo trains into two T2 distributions, calculating at least two porosity fractions for each of the two T2 distributions, estimating a shift of a porosity amount between the at least two porosity fractions, and detecting the motion artefact based on the shift.