Patent classifications
G01R33/387
MRI IMAGING SYSTEM USING PERMANENT MAGNET ARRAY
A tissue imaging system (10) includes a stationary array of magnets (12) arranged to generate an inhomogeneous main magnetic field (BO), a tissue holder (16) adjacent the array of magnets (12) and operative to move tissue (14) placed therein about and/or along a coordinate axis, one or more RF receive coils (20) adjacent the tissue holder (16) and the magnets (12), and an MRI processor in communication with the magnets (12), the RF receive coils (20) and the tissue holder (16). An image of the tissue (14) is created by using spatial encoding of magnetic resonance signals generated by the magnets (12) and RF receive coils (20) for different spatial orientations of the tissue (14) moved by the tissue holder (16) with respect to the magnets. Spatial inhomogeneities in the main magnetic field spatially modulate a phase of each of the magnetic resonance signals.
MRI IMAGING SYSTEM USING PERMANENT MAGNET ARRAY
A tissue imaging system (10) includes a stationary array of magnets (12) arranged to generate an inhomogeneous main magnetic field (BO), a tissue holder (16) adjacent the array of magnets (12) and operative to move tissue (14) placed therein about and/or along a coordinate axis, one or more RF receive coils (20) adjacent the tissue holder (16) and the magnets (12), and an MRI processor in communication with the magnets (12), the RF receive coils (20) and the tissue holder (16). An image of the tissue (14) is created by using spatial encoding of magnetic resonance signals generated by the magnets (12) and RF receive coils (20) for different spatial orientations of the tissue (14) moved by the tissue holder (16) with respect to the magnets. Spatial inhomogeneities in the main magnetic field spatially modulate a phase of each of the magnetic resonance signals.
Device for Reducing Magnetic Susceptibility Artifact
The present disclosure relates to a susceptibility artifact reducing vacuum bag for reducing local magnetic inhomogeneity inside a magnetic resonance imaging system, the vacuum bag comprising a mixture of diamagnetic composite material made of a diamagnetic material, such as pyrolytic graphite, and a filler material, the fraction of diamagnetic composite material and filler material selected such that the mixture has a net magnetic susceptibility corresponding substantially to the magnetic susceptibility of human tissue, the vacuum bag further comprising a valve for establishing an externally generated vacuum inside the vacuum bag.
Device for Reducing Magnetic Susceptibility Artifact
The present disclosure relates to a susceptibility artifact reducing vacuum bag for reducing local magnetic inhomogeneity inside a magnetic resonance imaging system, the vacuum bag comprising a mixture of diamagnetic composite material made of a diamagnetic material, such as pyrolytic graphite, and a filler material, the fraction of diamagnetic composite material and filler material selected such that the mixture has a net magnetic susceptibility corresponding substantially to the magnetic susceptibility of human tissue, the vacuum bag further comprising a valve for establishing an externally generated vacuum inside the vacuum bag.
Ultrafast MRI system and method
Magnetic Resonance Imaging (MRI), which is given the acronym ULTRA (Unlimited Trains of Radio Acquisitions), can eliminate magnetic gradient reversals and allow simultaneous MR signal acquisition from the entire object volume in each of a multitude of very small receiver coils arranged in a 3D array around the imaging volume. This permits a rate of MR signal acquisition that is greatly increased (e.g. 256 times) compared with existing techniques, with a full 3D image constructed in as little as 1 millisecond. Furthermore, noiseboth audible and electricalis substantially reduced. The advantages over conventional MRI include: 1. Clinical imaging can be completed in seconds, with good signal-to-noise ratio; 2. Signal-to-noise ratio is further increased by eliminating RF noise due to gradient switching; 3. Real-time functional MRI is possible, on millisecond timescales; 4. With single breath holds, high quality imaging of thorax and abdomen is possible. 5. ULTRA greatly reduces audible noise and vibration.
Method and magnetic resonance apparatus for generating at least one combination image dataset
In a method and apparatus for generating a magnetic resonance (MR) image MR data are acquired from a subject as datasets in parallel with multiple RF coils, with first parallel dataset being acquired with a first parameter set and at least one further parallel dataset being acquired with a second parameter set. A first intermediate image dataset and at least one further intermediate image dataset are reconstructed with at least one of (a) the first intermediate image dataset being reconstructed from said first parallel dataset using a calibration data item derived from said at least one further parameter set, and (b) said at least one further intermediate image dataset is reconstructed from said at least one further parallel dataset using a calibration data item derived from said first parameter set. A combination image dataset is generated by combining said first intermediate image dataset and said at least one further intermediate dataset.
INSULATOR AND/OR CONSTRUCTION MATERIAL FOR NMR APPLICATIONS
A compound consisting of the following components: (A) 40-99.99 weight percent of at least one thermoplastic or thermoset polymer material selected as a halogenated or perhalogenated polymer; (B) 0.01-60 weight percent of at least one inorganic particulate diamagnetic or paramagnetic material; (C) 0-39.99 weight percent of at least one additive different from (B); is proposed as a construction material in the detection-relevant spatial area (9) of a nuclear magnetic resonance device with a static magnetic field of at least 1 Tesla, and furthermore corresponding constructional elements, in particular sample holders, our proposed as well as method of manufacturing such constructional elements and uses of such constructional elements.
METHOD AND MAGNETIC RESONANCE APPARATUS FOR SHIMMING THE BASIC MAGNETIC FIELD BY OPERATION OF A SHIM DEVICE
In a magnetic resonance apparatus having a scanner that generates a basic magnetic field in an imaging volume, and an operating method to acquire data from an entirety of a recording volume, wherein the scanner has a global shim coil acting on the entire imaging volume, and a local shim coil acting, with the global shim coil, on a sub-volume containing a region of interest, a first adjustment volume is established that contains the recording volume. A smaller, second adjustment volume is established containing the region of interest, and at most, the sub-volume. Using a field map of the basic magnetic field that covers the first adjustment volume, shim currents are respectively identified for the global shim unit, for homogenizing the first adjustment volume, and for the local shim unit, for homogenizing the second adjustment volume, accounting for the effect of the first shim currents on the second adjustment volume.
METHOD AND MAGNETIC RESONANCE APPARATUS FOR SHIMMING THE BASIC MAGNETIC FIELD BY OPERATION OF A SHIM DEVICE
In a magnetic resonance apparatus having a scanner that generates a basic magnetic field in an imaging volume, and an operating method to acquire data from an entirety of a recording volume, wherein the scanner has a global shim coil acting on the entire imaging volume, and a local shim coil acting, with the global shim coil, on a sub-volume containing a region of interest, a first adjustment volume is established that contains the recording volume. A smaller, second adjustment volume is established containing the region of interest, and at most, the sub-volume. Using a field map of the basic magnetic field that covers the first adjustment volume, shim currents are respectively identified for the global shim unit, for homogenizing the first adjustment volume, and for the local shim unit, for homogenizing the second adjustment volume, accounting for the effect of the first shim currents on the second adjustment volume.
Method and apparatus for measuring magnetic field
A magnetic field measuring method in a magnetic resonance imaging (MRI) apparatus includes applying a radio frequency (RF) pulse to an object, acquiring first and second echo signals from a first readout gradient according to test gradients having different intensities, acquiring third and fourth echo signals from a second readout gradient according to the test gradients having different intensities, and determining a characteristic value of an eddy field based on an echo time (TE) of at least one of the first through the fourth echo signals.