Patent classifications
G01V3/00
Method and apparatus to acquire magnetic resonance image data
In a method and apparatus to acquire magnetic resonance image data; an examination subject is positioned in a magnetic resonance apparatus to acquire magnetic resonance image data of the examination subject with a magnetic resonance sequence, and sequence parameters of the magnetic resonance sequence are established. First control commands of the magnetic resonance sequence are generated using the established sequence parameters. The first control commands are optimized so as to generate an optimized magnetic resonance sequence, the optimization of the first control commands including a conversion of the first control commands into optimized control commands. A test to review the optimized magnetic resonance sequence is implemented, the test including a comparison of the first control commands with the optimized control commands. The optimized magnetic resonance sequence is executed to acquire the magnetic resonance image data with the optimized control commands depending on the result of the test.
System and method for free-breathing volumetric imaging of cardiac tissue
A magnetic resonance imaging (MRI) system and methods are provided for producing images of a subject. In some aspects, a method includes identifying a point in the cardiac cycle, performing an inversion recovery (IR) pulse at a selected time point from the pre-determined point, and sampling a k-space segment at an inversion time from the IR pulse that is substantially coincident with the pre-determined point. The method also includes repeating the IR pulse and k-space sampling for multiple inversion times, and multiple segments of k-space, in an interleaved manner, to generate datasets having T1-weighted contrasts determined by their respective inversion times. The method further includes reconstructing three-dimensional (3D) spatially-aligned images using the datasets, and generating a T1 recovery map by combining the 3D images. In some aspects, a prospective/retrospective scheme may be used to obtain data fully sampled in the center of k-space and randomly undersampled in the outer regions.
System and method for estimating a static magnetic field
A method includes applying a preparatory radiofrequency (RF) pulse at a first time instant to a Magnetic Resonance (MR) scanner configured to scan an object comprising a plurality of chemical species. The method further includes applying a phase sensitive pulse sequence at a second time instant to the MR scanner, wherein the preparatory RF pulse and a time delay between the first and the second time instants null a first subset of chemical species from the plurality of chemical species. The method further includes receiving an output signal from a second subset of chemical species from the plurality of chemical species in response to the phase sensitive pulse sequence. The method also includes estimating a static magnetic field map based on the output signal from the second subset of chemical species.
Method of monitoring carbon dioxide leakage in carbon capture and storage reservoirs
The method of monitoring carbon dioxide leakage in carbon capture and storage reservoirs estimates porosity and water saturation in a porous medium, such as brine-saturated shale, as is common in carbon capture and storage reservoirs, based upon measured electrical conductivity and seismic P-wave velocity. The estimated porosity and water saturation may be used for monitoring carbon dioxide leakage from a carbon dioxide reservoir to the overlying cap rock of the region. Measured electrical conductivity and seismic P-wave velocity data are used by the present method to estimate the porosity and water saturation in the cap rock. If a decrease in water saturation in the cap rock is found, this indicates that carbon dioxide may be leaking up from the carbon dioxide reservoir. An alert signal is then generated to indicate that there may be a carbon dioxide leak.
Nuclear magnetic flowmeter and method for operating a nuclear magnetic flowmeter
A nuclear magnetic flowmeter (1) for determining the flow of a medium flowing through a measuring tube (2), having a magnetic field generator (3) having permanent magnets for generating a magnetic field interfusing the medium over a magnetic field section L.sub.M, having a pre-magnetization section L.sub.VM located within the magnetic field section L.sub.M and having a measuring device also located in the magnetic field section L.sub.M including a coil-shaped antenna (4) with the length L.sub.1 serving as a measuring antenna. At least one coil-shaped antenna (5) is provided in the pre-magnetization section L.sub.VM for generating a pulse or pulse sequence spoiling the magnetization of the medium in the direction of the magnetic field.
RF coil unit and MRI apparatus
An RF coil unit of an embodiment includes a plurality of first coil elements each having a first main loop which receives a magnetic resonance signal and a plurality of second coil elements each having a second main loop and a sub-loop protruding from a portion of the second main loop. Any combination of two coil elements chosen from the plural first coil elements and the plural second coil elements is arranged in an overlap area where areas surrounded by one and another one of the two coil elements overlap in such a way that the overlap area is located in an area surrounded by the first main loop.
Magnetic field gradient monitor and magnetic field gradient waveform correction apparatus and methods
Method for correcting the magnetic field gradient waveform in a magnetic resonance measurement including extracting an impulse response from the measured step response of a magnetic resonance system, determining the slew rate of the system during the step response measurement, modifying the desired output waveform such that the desired output waveform is constrained to within the slew rate and the bandwidth of the system, and determining the required pre-equalized input waveform.
Method and apparatus for generating a specific flip angle distribution in MRI
The present invention provides a method and apparatus for generating a specific flip angle distribution in magnetic resonance imaging; the method uses a plurality of RF transmission coils combined with linear and nonlinear spatial encoding magnetic fields to generate a homogeneous flip angle distribution.
Magnetic field trimming in an atomic sensor system
One example embodiment includes an atomic sensor system. The system includes a magnetic field generator configured to generate a magnetic field in a volume. The system also includes a vapor cell arranged within the volume and comprising a polarized alkali metal vapor. The system further includes at least one magnetic field trimming system configured to generate a magnetic field gradient within the vapor cell separate from the magnetic field to provide a substantially uniform collective magnetic field within the vapor cell.
Head-up display with eye-tracker for MRI applications
A head-up display and eye-tracker system, suitable for use with a patient in an MRI tube during an MRI procedure. An electronic display assembly includes an outer display tube housing for housing an electronic display device for generating images, the outer tube housing fabricated of an electrically conductive, non-ferrous material. An eye-tracker camera assembly includes an outer camera tube housing for housing an electronic camera sensor, the outer tube camera housing fabricated of an electrically conductive, non-ferrous material. An eyepiece assembly includes an outer housing. A beam splitter assembly includes a beam splitter block having a receptacle holding a beam splitter, the block formed of an electrically conductive, non-ferrous material. The beam splitter reflects light from the display onto the patient's eye, and allows light reflected from the patient's eye to pass to the camera sensor. In another embodiment as a display system, the eye-tracker camera assembly is omitted.