Abstract: An apparatus to control an antenna arrangement in a magnetic resonance apparatus has an amplifier with an input connected to a radio-frequency transmission signal to be amplified. The antenna arrangement has at least one antenna element for emission of the amplified transmission signal. The antenna element has an infeed point with two terminals, wherein the amplified transmission signal is connected at the terminals. The amplifier is connected on the output side with two terminals of the infeed point. The antenna element has at the infeed point, a mounting surface to accommodate the amplifier.

Abstract: A method for reconstructing an image in a magnetic resonance imaging system is provided. The method includes steps of acquiring magnetic resonance signals from a plurality of receiver coils placed about a subject, each receiver coil having a coil sensitivity, iteratively polling each acquired magnetic resonance signal for determining one or more significant wavelet components of each acquired magnetic resonance signal by utilizing a coil sensitivity function of each receiver coil for each acquired magnetic resonance signal, iteratively determining one or more coefficients based on the one or more significant wavelet components to generate a plurality of coefficients for each acquired magnetic resonance signal, reconstructing an image utilizing a corresponding plurality of coefficients corresponding to each acquired magnetic resonance signal, and generating a composite image by combining the reconstructed images.

Abstract: The present invention discloses an apparatus and method to track the movement of a target. One embodiment tracks the movement of the patient during medical imaging scanning using optical technology. Optical systems record the position and movement of the target and provide inputs to a processor. The processor is capable of performing mathematical analysis of the movement of the target to determine the positional shift of the patient. Weighted averages, phase correlation, Fourier-Mellin algorithms, and cross-correlation of data related to X-Y translation are used to calculate movement of the target subject. Feedback related to the movement is provided to the medical imaging scanning machine which allows for adjustments in focusing coils for real time tracking of the patient's movements during the procedure. As a result, the medical image scanning procedure becomes more accurate as it is adjusted for the patient's movements.

Abstract: For detuning of radio-frequency coils (in magnetic resonance imaging and spectroscopy, for example), a conducting element (102) of a transmission cable is configured to form a primary resonant circuit tunable to at least one first resonance frequency. A second conducting element (104) of the transmission cable is configured to form a switching circuit that is electrically insulated from and reactively coupled via inductive coupling and/or capacitive coupling to the primary resonant circuit, and is adapted to tune the primary resonant circuit to at least one second resonance frequency, thereby detuning the primary resonant circuit.

Abstract: An arrangement and a support device for attaching local coils to a patient for a magnetic resonance examination includes at least one local coil that is designed to acquire magnetic resonance signals and a support device. The support device is designed to accommodate the at least one local coil and to attach the at least one local coil on the patient. The support device is designed as a gas-filled cushion that changes its shape dependent on the gas pressure therein. The gas-filled cushion has a device for changing the gas pressure, such when a gas pressure change occurs the local antenna is pressed on the patient due to the resulting change in shape of the cushion.

Abstract: An array coil including at least three conductive elements arranged at predetermined intervals, each of the conductive elements being in the form of a loop, and a plurality of switches that enable the conductive elements to be connected together according to a plurality of connecting patterns.

Abstract: Viscosity of heavy oil is determined in situ in a formation by making nuclear magnetic resonance (NMR) measurements in the formation, and then calculating viscosity according to an equation of the form T 2 ? LM = a + b ? ( ? T ) c , where T is the temperature of the heavy oil sample, ? is the viscosity, T2LM is the logarithmic mean of the T2 distribution spectrum of the sample, and a, b, and c are non-zero constants. Typically, constant b has a value between 5 and 7 and constant c has a value between ?0.7 and ?0.5.

Abstract: In a method for determination of flip angle distributions for various antenna transmission configurations in a magnetic resonance system, magnetic resonance measurements are implemented with the various transmission configurations, with the reception configuration being identical for all implemented magnetic resonance measurements, and all magnetic resonance measurements for the various transmission configurations are implemented with a specific pulse sequence.

Abstract: A magnetic resonance imaging apparatus comprises a plurality of high-frequency reception coils, sensitivity distribution information obtaining means for calculating sensitivity distribution information of each of the high-frequency reception coil, sensitivity distribution storage means for storing the sensitivity distribution information, measuring means for acquiring magnetic resonance signals by thinning out encode steps of a k-space, image reconstructing means for reconstructing images using the magnetic resonance signals, and means for performing unfolding calculation using the sensitivity distribution information and the image, thereby to acquire the unfolded image.

Abstract: A method for producing a magnetic resonance image indicative of mechanical waves applied to a subject is provided. Mechanical waves are applied to the subject at a selected frequency to induce oscillatory motion in tissues within the subject at the same frequency. A spin-lock radiofrequency pulse, having a resonance frequency matched to that of the induced oscillatory motion, is applied to the subject. This results in a spin-lock condition, during which transverse magnetization experiences rotary saturation resulting from magnetic field fluctuations produced by the oscillatory motion. Image data is acquired from the saturated transverse magnetization and images are reconstructed. As a result of the rotary saturation, these images exhibit darkening in those voxel locations affected by the oscillatory motion. In this manner, an image indicative of the applied mechanical waves is produced.

Abstract: An instrument locally measuring mobility of a protic solvent in a sample 115 based on the gradient magnetic field NMR method has a sample stage 116 on which the sample 115 is placed, a magnet 113 applying a static magnetic field to the sample 115, a G coil 151 and a G coil 153 applying a gradient magnetic field to the sample 115, a small-sized RF coil 114 smaller in size than the G coil 151 applying an oscillating magnetic field for excitation and acquiring an NMR signal corresponded to the oscillating magnetic field for excitation and the gradient magnetic field; a pulse control unit 108 allowing application of the gradient magnetic field and oscillating magnetic field for excitation to be executed according to a predetermined pulse sequence; and an operation unit 130 calculating the mobility at the specific position of the G coil 151, based on information of the NMR signals acquired corresponding to different gradient magnetic fields.

Abstract: An MR imaging apparatus is disclosed, wherein the MR imaging apparatus includes a plurality of gradient coils positioned about a bore of a magnet, and an RF transceiver system controlled by a pulse module to transmit RF signals to an RF coil assembly. The MR imaging apparatus also includes a controller coupled to the plurality of gradient coils and the RF transceiver system and programmed to obtain MR image signals at different echo times from a subject containing metabolites having known characteristics. The controller is further programmed to reconstruct images of the metabolites in a selected region of interest (ROI) using a probabilistic mathematical expression based on known information regarding an image acquisition process and using a spatial distribution of the metabolites to account for artifacts in the images.

Abstract: Coil sensitivity of a receive coil to a gradient null location is measured and, from the measurements, a coil calibration value is determined and used to modify the MR data acquired with that receive coil to reduce the adverse effects of gradient nulling on MR images. Coil sensitivity values are determined for each coil of a coil array and the data for each coil is respectively weighted. An image that is substantially free of gradient null artifacts or ghosting is then reconstructed from the weighted data.

Abstract: An apparatus and method for reconstructing multi-spectral 3D MR images includes a magnetic resonance (MRI) apparatus that includes an MRI system having a plurality of gradient coils positioned about a bore of a magnet, and an RF transceiver system and an RF switch controlled by a pulse module to transmit RF signals to an RF coil assembly to acquire MR images. The MRI apparatus also includes a computer programmed to acquire a plurality of three-dimensional (3D) MR data sets, wherein each 3D MR data set is acquired using a central transmit and receive frequency set to an offset frequency value that is distinct for each 3D MR data set. The computer is also programmed to simultaneously generate a composite image and a magnetic field map based on the plurality of 3D MR data sets.

Abstract: The system for measuring a magnetic resonance signal within a sample (4) placed in a static external magnetic field (H) includes an excitation device (1 to 3, 6 to 10) for applying high-intensity radio-frequency pulses at a predetermined emission frequency fe in a measurement zone containing the sample (4). The excitation device includes an excitation coil (3) tuned to the predetermined emission frequency fe and disposed in the vicinity of the sample (4) in such a way as to produce an electromagnetic field essentially perpendicular to the static external magnetic field (H). The system further includes at least a superconductive-magnetoresistive hybrid sensor (5) including a superconductive loop having a constriction adapted to increase significantly the current density and at least a magnetoresistive sensor placed in the immediate vicinity of said constriction (72) and being separated therefrom by an insulative deposit.

Abstract: A method and apparatus for treating a sample for acquiring high-definition magnetic resonance images (MRI images) or high resolution nuclear magnetic resonance (NMR) spectra even in the presence of magnetic field distortions within one or multiple scans. The spatial nature and temporal dependence of the field inhomogeneities are determined a priori using any of several literature procedures. A static or oscillating magnetic field gradient is applied on the sample so as to endow spins at different positions within the sample with different resonance frequencies. A phase- and amplitude-modulated radiofrequency (RF) pulse is applied in unison with the magnetic field gradient so as to endow spins at different positions within the sample with a homogeneous excitation/inversion profile.

Abstract: A method for detecting the presence of precipitants in a hydrocarbon stream, the method comprising introducing at least a portion of the hydrocarbon stream into a measurement chamber of an NMR measuring device, assaying the fluids in the chamber with proton nuclear magnetic resonance to obtain NMR signals, and processing the NMR signals to detect the formation of precipitants in the hydrocarbon stream. The method may be carried out at first and second locations, and NMR signals obtained at the two locations compared to detect precipitation of precipitant between the two locations. A method of monitoring the water content of a hydrocarbon stream in a flowline comprising introducing at least a portion of the hydrocarbon stream into an NMR measuring device, measuring a baseline NMR water signal of the hydrocarbon stream and comparing subsequent NMR water signals with the baseline NMR water signal to detect changes in the water content of the hydrocarbon stream.

Abstract: A method and apparatus for identifying local RF coils in a MR system includes a microcontroller that is provided in the bore of the system. The microprocessor determines when local RF coils are connected, identifies the coils, and provides the information to an MR scanner. The controller is shielded to prevent electromagnetic interference.

Abstract: A pseudo-Marchand balun, compound balun and tunable multi-resonant coaxial balun, and NMR probes employing each such balun, and a fine balance and impedance adjustment module and a multi-layer transmission line for use in such NMR probes.

Abstract: A radio frequency (RF) coil for a magnetic resonance imaging (MRI) system includes a first end ring section containing a plurality of openings and a second end ring section containing a plurality of openings. A plurality of rungs is disposed between the first end ring section and the second end ring section. Each rung has a first end connected to the first end ring section and a second end connected to the second end ring section. Each rung can also include a plurality of openings. The openings in the end rings and rungs reduces eddy currents and improves RF performance of the RF coil.