Abstract: Systems and methods for determining T2 cutoff are described. T2 cutoff can be derived from magnetic susceptibility measurements. By providing a depth curve of T2cutoff, improved permeability estimations from NMR can be generated. By combining a magnetic susceptibility tool and an NMR tool, a dynamic T2cutoff can then be provided, together with the standard NMR log, according to some embodiments. According to some embodiments the improved permeability estimations can be provided automatically and in real time at the wellsite.

Abstract: A radiofrequency (RF) coil assembly (18,18?) for use in a magnetic resonance system (10) includes a radiofrequency coil (42) and a plurality of memory resistive elements (46,56,62,72) which each retains a selected resistive state after a control signal is removed. A detune circuit (44), part of the radiofrequency coil assembly, includes a memory resistive element (46) which switches the radiofrequency coil between a tuned and detuned state. Connected between the radiofrequency coil and a pre-amplifier (52), a blanking circuit (54) includes a memory resistive element (56) to short circuit an input of the pre-amplifier. A multiplexing circuit (60) includes a plurality of memory resistive elements (62) to selectively couple the selected outputs of the radiofrequency coils to a receiver (26).

Abstract: Apparatus, methods, and other embodiments associated with magnetic resonance (MR) trajectory correcting using GRAPPA operator gridding (GROG) are described. One example method includes identifying an on angle or regular portion of a projection in an MR trajectory and then computing base GROG weights for that portion. The example method includes identifying a shift direction and a shift amount for the projection. The shift direction is configured to shift the projection towards a desired point in k-space and the shift amount is configured to shift the projection by a desired amount in the shift direction. With a shift direction and amount available, the example method corrects for a gradient delay by manipulating the MR source signal data using the shift direction and the shift amount. In one embodiment, a gradient delay can be determined and used to calibrate an MRI apparatus.

Abstract: For use in MR imaging of a patient a plurality of surface electrodes such as ECG or defibrillator are provided for obtaining electrical signals for determining electrical activity within the body of the patient and remain in place during the MR imaging. The surface electrodes include a quick disconnect wire for carrying the signals to a signal processing system to be removed during the MR imaging to prevent heating. Each electrode comprises a conductive layer divided by slits into separate side by side sections to reduce eddy currents which are induced in the surface electrodes when they are exposed to variations in the magnetic field. The sections all are connected through the layer to the conductive location to allow the signal therefrom to be connected to the communication conductor.

Abstract: A magnetic resonance apparatus includes a magnet unit and a housing unit enclosing the magnet unit. A noise prevention unit is provided which is arranged between the magnet unit and the housing unit enclosing the magnet unit and which has at least one noise prevention element made of an insulating foam. The at least one noise prevention element has a D-shaped cross-sectional area.

Abstract: An enhanced radio frequency transmitter suitable for use in a nuclear magnetic resonance logging tool, may employ a power amplifier that comprises two pairs of switching amplifiers and a summation stage. The first pair of switching amplifiers together generate a first pair of pulse sequences having an adjustable phase difference, while the second pair of switching amplifiers generate a second pair of pulse sequences, each pulse sequence in the second pair being provided a fixed phase offset from a respective pulse sequence in the first pair. The summation stage forms a combined signal from the pulse sequences in both said first and second pairs. The fixed phase offset operates to at least partly cancel a higher harmonic of the pulse sequences from the combined signal, thereby reducing energy losses downstream from the transmitter.

Abstract: A method of measuring precessing magnetization includes providing a first site characterized by a first spin order and providing a second site. The method also includes transferring a portion of the first spin order from the first site to the second site. The second site is characterized by a second spin order orthogonal to the first spin order. The method further includes exposing a sample including the first site and the second site to a magnetic field, measuring a precessing magnetization of at least one of the first site or the second site, repeating the transferring a portion of the first spin order from the first site to the second site, and repeating the measuring of the precessing magnetization.

Abstract: Systems and methods for insulating superconducting magnets, such as a cryogen vessel of a magnetic resonance imaging (MRI) system having therein one or more superconducting magnets are provided. One system includes a thermal insulator having a first plurality of reflector layers and a non-deformed spacer layer between adjacent layers in the first plurality of reflector layers. The thermal insulator further includes a second plurality of reflector layers and a deformed spacer layer between adjacent layers in the second plurality of reflector layers.

Abstract: An MRIS gradient coil assembly 2A comprising a first coil layer comprising a first conductive coil portion 3X and a second coil layer comprising a second conductive coil portion 3Y. A first screening layer 6X is disposed between the first 3X and second 3Y coil layers and comprises at least one sheet of screening material. At least one insulating layer 4X comprising insulating material is provided between the first 3X conductive coil portion and the first screening layer 6X. Further the assembly comprises at least one discrete contact means 7 electrically connecting the first conductive coil portion 3X to the sheet of screening material 6X while the sheet of screening material 6X is kept from electrically contacting with the first conductive coil portion 3X, except via the at least one discrete contact means, by the at least one layer of insulating material 4X. The screening material might typically comprise a semi-conductive sheet.

Abstract: Techniques include determining, non-invasively and without applying deformational stress, a nuclear magnetic resonance relaxation rate at a volume inside a subject. The method also includes determining a mechanical property of material at the volume inside the subject based on the nuclear magnetic resonance relaxation rate.

Abstract: An apparatus for use in a magnetic resonance system including an operative component configured to perform a useful operation in a magnetic resonance system; an electrical cable connected with the operative component to provide electrical communication with the operative component; and a resonant circuit including at least a portion of the electrical cable, the resonant circuit having a first impedance pole at a first magnetic resonance frequency and a second impedance pole at a second magnetic resonance frequency different from the first magnetic resonance frequency.

Abstract: A magnetic resonance imaging apparatus according to an embodiment includes a sequence control unit that controls a gradient magnetic field power supply, thereby performing a pulse sequence including the application of a continuous readout gradient magnetic field pulse. The sequence control unit controls the gradient magnetic field power supply such that the slew rate of the gradient magnetic field pulse is reduced in stages as the output voltage of a gradient magnetic field amplifier is reduced in stages.

Abstract: In a method and magnetic resonance apparatus for the hyperintense display of areas containing particles of magnetically active substances, in an examination region in a measurement volume of a magnetic resonance scanner, measurement data from the examination area are generated by a pulse sequence and recorded, the pulse sequence causing an echo time of less than one millisecond, so that a suppression of undesired signals is also caused.

Abstract: A method for producing hyperpolarized sample material for use in magnetic resonance investigations involves preparing a target material containing high ? nuclei with a short T1, a polarizing agent with a broad EPR line, and low ? nuclei with a long T1. The polarizing agent in the target material is irradiated with microwave radiation, wherein the target material is at a cryogenic temperature and exposed to a static magnetic field B0?4.0 T, thus polarizing the high ? nuclei by DNP, and the polarization is transferred from the high ? nuclei to the low ? nuclei by Cross Polarization. A dissolved sample material is prepared containing the hyperpolarized low ? nuclei from the target material. Nuclei with a long longitudinal relaxation time T1 can thereby be quickly hyperpolarized to a high polarization level.

Abstract: Phase error in MR imaging is corrected in real time by providing adaptive RF pulses and corresponding adaptive magnetic field gradients to mitigate the effect of phase error in the imaging subject. A real time phase error map is obtained, and then adaptive RF pulses and corresponding field gradients are applied that remove the problematic effects of the phase error. Depending on details of the MR imaging mode being employed, there are several ways this removal can be done. Phase error can be cancelled by providing RF pulses that make the phase in the imaging subject uniform. Another approach is to make the adaptive RF pulses insensitive to the phase errors that are present.

Abstract: A system, method, software arrangement and computer-accessible medium for performing electronic cleansing of CT colonography images are provided. In this system, method, software arrangement and computer-accessible medium, the digital bowel cleansing can be performed to remove tagged bowel contents from the images. The digital bowel cleansing can apply a local shape analysis throughout the images and use a shape-based speed function to detect the folds and polyps structures while removing the tagged bowel contents region. The system, method, software arrangement and computer-accessible medium can enable a medical examiner to perform an accurate virtual colonoscopy on a patient, without the need for thorough patient preparation.

Abstract: Methods, systems and apparatus for magnetic resonance imaging that facilitate applying a gradient waveform to generate a k-space trajectory in a subject, applying radio frequency (RF) pulses having a pseudorandom phase distribution, such that the RF pulses are applied to the subject at a plurality of non-uniform locations near a center of the k-space trajectory and collecting, based on the applied RF pulses and the applied gradient waveform, imaging data from the subject.

Abstract: A microwave resonator device (1), being configured in particular for electron spin resonance measurements, comprises a resonator being resonant with first and second microwave field modes and including first and second resonance sections (7, 8) arranged along a longitudinal axis (2) of the resonator, and a coupling unit being arranged between the first and second resonance sections, wherein the coupling unit includes a conducting plate (16) being arranged on the longitudinal axis (2) and covering a central portion of a cross-sectional area of the resonator, the conducting plate (16) is adapted to adjust a first mode frequency of the first microwave field mode, and the conducting plate (16) is arranged at a field minimum of the second microwave field mode. Furthermore, a method of conducting an electron spin resonance measurement with a sample to be investigated is described.

Abstract: A method for measuring diffusional anisotropy in diffusion-weighted magnetic resonance imaging. The method includes determining an orientation diffusion function (ODF) for one or more fibers within a single voxel, wherein the ODF includes lobes representative of a probability of diffusion in a given direction for the one or more fibers. The method also includes characterizing an aspect ratio of the lobes. The method further includes determining a multi-directional anisotropy metric for the one or more fibers based on the aspect ratio of the lobes.

Abstract: A magnet assembly primarily for use in MRI applications is disclosed. The magnet assembly is composed of a single disk and ring permanent magnet set connected to a C-type magnet yoke and return fixture with asymmetrically arranged poles. Together, the permanent magnets create a strong magnetic field that has a large static gradient in the central enclosure. The magnet assembly is primarily designed for diffusion based MRI scanning but can perform routine MRI scanning as well.