A system and method for performing parallel magnetic resonance imaging (pMRI) process using a low-field magnetic resonance imaging (IfMRI) system includes a substrate configured to follow a contour of a portion of a subject to be imaged by the IfMRI system using a pMRI process. A plurality of coils are coupled to the substrate. Each coil in the plurality of coils has a number of turns and an associated decoupling mechanism selected to operate the plurality of coils to effectuate the pMRI process using the IfMRI system.

An antenna array includes a plurality of linear electromagnetic resonators having longitudinal axes oriented parallel to one another and not aligned, and at least one decoupling device arranged between two the linear electromagnetic resonators, wherein the decoupling device comprises a plurality of open-loop electromagnetic resonators that are matched to a frequency located in the bandwidth of the two the adjacent linear electromagnetic resonators, that are electrically insulated and that are arranged in a plurality of planes that are not parallel to a plane containing the longitudinal axes of the two the linear electromagnetic resonators. Nuclear magnetic resonance imaging apparatus comprising such an antenna array is also provided.

A dual-nuclear radio frequency (RF) coil device includes a first RF coil and a second RF coil. The first RF coil includes at least one adjustment capacitor, the first RF coil is configured to generate a first magnetic field, and a direction of a primary magnetic field of the first magnetic field is a first direction. The second RF coil includes an electric dipole and a tuning and matching circuit connected between two conductors of the electric dipole. The second RF coil is configured to generate a second magnetic field and a direction of a primary magnetic field of the second magnetic field is a second direction; the electric dipole is disposed in a center line of the first RF coil and an insulating layer is disposed between the electric dipole and the first RF coil; and the first direction is perpendicular to the second direction.

A magnetic resonance imaging (MRI) system radio frequency (RF) subsystem and a coil decoupling apparatus and method used therein. The MRI system RF subsystem comprises a body coil and a surface coil for receiving MR signals, and also comprises a preamplifier for amplifying the MR signals received by the body coil; the coil decoupling apparatus comprises a phase shifter, which is connected between the preamplifier and the body coil, and used for receiving an external voltage regulation signal to regulate an operation voltage thereof, wherein the voltage regulation signal is determined according to a current patient's weight.

The exemplary system and method facilitate excitation of RF magnetic fields in ultra-high field (UHF) magnetic resonance (MRI) systems (e.g., MRI/NMR system) using a slotted waveguide array (SWGA) as an exciter coil. The exemplary exciter coil, in some embodiments, is configurable to provide RF magnetic field B.sub.1.sup.+ with high field-uniformity, with high efficiency, with excellent circular polarization, with negligible axial z-component, with arbitrary large field of view, and with exceptional possibilities for field-optimizations via RF shimming.

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.

A multichannel array coil of an MRI apparatus achieves both a wide sensitivity and low noise. An RF coil (array coil) is provided with a plurality of subcoils. Each of those subcoils is adjusted to be receivable of nuclear magnetic resonance signals, and also adjusted so that a part of current (first current) passing through one subcoil upon receipt of the signals flows into the other subcoil in the form of sub-current. A flowing direction of the first current is opposite to the flowing direction of the sub-current, and an electric field generated by the first current within a subject and an electric field generated by the first sub-current within the subject intensify each other in the space between a first loop coil unit and a second loop coil unit. Accordingly, noise correlation that is determined by an inner product of the electric fields is reduced, thereby achieving low noise.

The invention discloses an RF coil element and an RF coil for magnetic resonance imaging, wherein the RF coil element is connected with an active loss circuit capable of actively dissipating and absorbing RF power in the RF coil element to decrease the Q value of the coil element. The active loss circuit is connected to the coil element to absorb the RF power in the coil element to decrease the Q value of the coil element, so that the coupling degree (correlation coefficient) between every two elements of an array coil formed by the coil elements is decreased, thus improving the parallel transmission (pTX) performance and the uniformity of a magnetic resonance RF transmission field.

Parallel transmit Magnetic Resonance MR scanner used to image a conductive object such as an interventional device like a guidewire within a subject. This is achieved by determining which Radio Frequency RF transmission modes produced by the parallel RF transmission elements couple with the conductive object and then transmitting at significantly reduced power so as to prevent excessive heating of the conductive object to an extent that would damage the surrounding tissue of the subject, for example, the coupling RF transmission modes may be generated at less than 30%, preferably around 10% of the normal power levels that would conventionally be used for MR imaging. However, even at these low power levels sufficient electric currents are induced in the conductive device to cause detectable MR signals; the location of the conductive object within the subject can thus be visualised. By fast alternate, or simultaneous, iterative application of low-power coupling mode and normal-power non-coupling modes, both the subject and the conductive object can be imaged. During the calibration step of determining which RF transmission modes couples with the conductive object, instead of physically measuring the current induced in the conductive object using sensors, imaging the conductive object using additional very short series of flip angle RF pulses (vLFA) gives a good approximation of the coupling matrix.

A flexible RF coil with excellent portability is provided. The RF coil includes a first coil, a first skeleton, and a second skeleton, the first skeleton and the second skeleton being rod shaped. The first coil includes a first loop made from a conductor that receives radio frequency signals, and a first signal detector that is inserted in series into the first loop and that detects the signals received by the first loop. The first skeleton and the second skeleton are arranged with a spacing in the short axis direction, the first signal detector is mounted on the first skeleton, and a portion of the first loop that faces the first signal detector is mounted on the second skeleton. The first loop is deformable, and the spacing between the first skeleton and the second skeleton is changeable in accordance with the deformation of the first loop.