Patent classifications
G01R33/3635
Cylindrical-like single layer technology (SLT) magnetic resonance imaging (MRI) array coil with at least one row as a birdcage coil in transmit mode
Embodiments relate to cylindrical MRI coils with at least one row as a birdcage row in a transmit mode. One example embodiment is a MRI Radio Frequency (RF) coil array comprising two or more rows of four or more RF coil elements each. Each of the RF coil elements can be configured to resonate at a working frequency of the coil array in a receive mode. At least one of the rows can be configured as a birdcage coil in the transmit mode, and the two or more rows can inductively couple together such that all the two or more rows can resonate together in the transmit mode at the working frequency.
Minimizing coupling in multi-row cylindrical-shaped magnetic resonance imaging (MRI) radio frequency (RF) coil
Embodiments relate to cylindrical MRI coil arrays with reduced coupling between coil elements. One example embodiment comprises two or more rows, wherein each row comprises at least three RF coil elements of that row enclosing a cylindrical axis; and a ring comprising an associated portion of each RF coil element of a first row and a second row electrically connected together, wherein the associated portion of each RF coil element of the first row and of each RF coil element of the second row comprises an associated capacitor of that RF coil element, and wherein the associated capacitor of that RF coil element is configured to reduce coupling among the RF coil elements of the first row and the RF coil elements of the second row.
MRI scanner with active interference suppression and interference suppression method for an MRI scanner
An MRI scanner and a method for operation of the MRI scanner are provided. The MRI scanner has a first receiving antenna for receiving a magnetic resonance signal from a patient in a patient tunnel, a second receiving antenna for receiving a signal having the Larmor frequency of the magnetic resonance signal, and a receiver. The second receiving antenna is located outside of the patient tunnel or near an opening thereof. The receiver has a signal connection to the first receiving antenna and the second receiving antenna and is configured to suppress an interference signal by the second receiving antenna in the magnetic resonance signal received by the first receiving antenna.
RF MAGNETIC FIELD HOMOGENEITY AND MAGNETIC RESONANCE IMAGE UNIFORMITY USING INDUCTIVE COUPLING
An apparatus, method, and system are disclosed for improving uniformity of RF magnetic field in an MRI system, and thereby improving both signal-to-noise ratio and uniformity of imaging sensitivity across a sampling volume, to provide more uniform MRI images. A passive LC resonator develops induced EMF and induced currents in a primary RF magnetic field; the secondary magnetic field produced thereby can counteract magnetic field amplitude gradients to produce a more homogeneous RF magnetic field. In systems with separate transmit and receive coils, a shunt detuning circuit is pulsed ON to prevent interference during the transmit period. In a dual-frequency MRI machine (e.g. 19F and 1H), the RF magnetic field at the lower operating frequency can be homogenized by tuning the resonance of the passive resonator between the two operating frequencies. Another resonator can improve RF field uniformity at the higher operating frequency. Variants and experimental results are disclosed.
Operating an MRI apparatus
A method of operating a magnetic resonance imaging (MRI) apparatus includes exciting a body coil of the MRI apparatus to emit a radio-frequency signal, determining a center frequency of a resonance curve of the body coil, and calculating a magnet target frequency based on the determined center frequency. A magnet is ramped to the magnet target frequency.
Multi-channel magnetic resonance spectrometer modules and systems
An example multi-channel magnetic resonance (MR) system is described. The system includes a plurality of radio frequency (RF) coils and a plurality of spectrometer transceiver channels. Each of the channels including a spectrometer coupled a respective set of the RF coils. The spectrometer is configured to transmit RF signals to excite respective RF coils and to receive MR sensor signals from the excited respective RF coils responsive to excitation thereof. The spectrometer is configured to perform MR spectrometry to provide MR measurement data based on the received MR sensor signals for the respective channel. A synchronization module is coupled to the spectrometer of the respective channel. The synchronization module is configured to synchronize the spectrometer of the respective channel with spectrometers in other channels via a communication link.
Magnetic resonance imaging apparatus
A magnetic resonance imaging apparatus according to an embodiment includes a static magnetic field generator, a transmit/receive system, and an acquiring means. The static magnetic field generator is configured to apply a second static magnetic field in addition to a first static magnetic field serving as a reference. The transmit/receive system is configured to perform transmitting and receiving at a single frequency. The processing circuitry is configured to acquire a magnetic resonance signal by employing the transmit/receive system. The transmit/receive system is configured to perform transmitting and receiving at a resonance frequency of a hydrogen nucleus in a state in which the first static magnetic field is applied and is configured to perform transmitting and receiving at a resonance frequency of a nuclide different from the hydrogen nucleus in a state in which the second static magnetic field is applied in addition to the first static magnetic field.
Coil facility for a magnetic resonance installation and magnetic resonance installation
A coil facility for a magnetic resonance installation and a magnetic resonance installation having such a coil facility are provided. The coil facility in this case includes a double-resonant transmit resonator for two frequencies and a first receiver and a second receiver, each for one of the two frequencies. The coil facility has an actuator system for effecting a relative spatial transposition of the transmit resonator, the first receiver, and the second receiver into various settings. In a first setting, only the first receiver, and in a second setting, only the second receiver, for receiving corresponding MR signals is arranged in an examination space that is at least sectionally surrounded by the transmit resonator.
Methods and systems for low to ultra-low magnetic field nuclear magnetic resonance for detecting chemical nerve agents
A nuclear magnetic resonance (NMR) system is configured to detect chemical threat material. The system comprises a magnet configured to generate a magnetic field of about 300 millitesla or less; and a probe configured to detect nuclear relaxation of at least two nuclei selected from the group consisting of .sup.1H, .sup.19F, .sup.31P and .sup.14N, and detect the spin density of nuclei selected from the group consisting of .sup.1H, .sup.19F, .sup.31P and .sup.14N, following excitation.
Magnetic resonance imaging of different nuclear spin species with the same radio frequency coil
Systems and methods for magnetic resonance imaging (“MRI”) of multiple different nuclear spin species using the same radio frequency (“RF”) coil are described. Generally, multiple different nuclear spin species are imaged using the same RF coil by using an MRI system whose magnetic field can be rapidly ramped between a number of different, and arbitrary, magnetic field strengths. The magnetic field of this MRI system can be ramped to different values in reasonable amounts of time (e.g., in a time frame that is feasible within an imaging study).