Aspects of photonic band gap resonators for magnetic resonance are described. In one example, an apparatus includes a 1D structure having a plurality of layers. A respective thickness of the individual layers is one-quarter of a respective wavelength of a target magnetic resonance frequency within the individual layers of the plurality of layers, or a multiple thereof. A first layer has a first dielectric constant, and a second layer that is adjacent to the first layer has a second dielectric constant. A defect includes a sample. The defect has a thickness that is approximately up to one-half of a wavelength of the target magnetic resonance frequency within the defect.

The embodiments relate to a body coil, to a magnetic resonance device, and to a method for operating a magnetic resonance device. The body coil includes at least one antenna unit and at least one pre-amplification unit, wherein the pre-amplification unit is arranged at a feed point of the antenna unit, wherein the pre-amplification unit has an input reflection factor at the feed point of the antenna unit whose value is greater than 0.7.

Techniques provide for passive Q switching in a bimodal resonator environment, where magnetic resonators are coupled for power transfer. A passive Q switch is responsive to a driving power from one magnetic resonator coupled to another magnetic resonator. After the driving power reaches a threshold, the passive Q switch shunts the receiving magnetic resonator, at least partially, to reduce the Q of that second resonator, which allows faster detection operation of the second resonator in some applications. The technique allows for fast Q switching in a bimodal resonator system, especially one having resonators having magnetic fields that are orthogonal to one another.

In a multi-channel array coil used as an RF coil of an MRI apparatus, even when magnetic coupling occurs between the respective sub-coils, it is possible to suppress the influence of a current flowing through the sub-coil of a coupling counterpart to maintain the desired sensitivity and suppress deterioration of image quality. Therefor, even when magnetic coupling occurs between sub-coils constituting the multi-channel array coil used as the RF coil of the MRI apparatus, the sub-coils are connected to a signal processing circuit so that a phase difference between a rotating magnetic field generated by the influence of a current flowing through the sub-coil of the coupling counterpart and a rotating magnetic field generated by the sub-coil is less than 90 degrees.

A coupling device is provided for coupling microwave radiation from a first microwave structure, in particular a microwave waveguide, into a second microwave structure, in particular a microwave resonant cavity, wherein the first and second microwave structures share a common wall, through an iris opening in said wall in front of which the coupling device is positioned on the side of the first microwave structure, in particular wherein the coupling device is of a basically cylindrical shape, characterized in that the coupling device comprises N electrically conducting conductor loops, with N3, preferably 3N20, that the conductor loops are arranged coaxially in an array along a z-axis, and that axially neighboring conductor loops are separated by a dielectric. The inventive coupling device allows for a larger coupling coefficient, and in particular allows for a larger dynamic range.

A radiofrequency detection and acquisition system, which is based on SQUID and configured to be integrated into a nuclear magnetic resonance system, comprises a primary detection antenna, a flux transformer having an inlet winding connected to the primary detection antenna, a low critical temperature SQUID device for capturing the magnetic flux produced by an outlet winding of the flux transformer and supplying a secondary detection signal, a cryogenic device for cooling the SQUID device and the flux transformer, and means for processing the secondary detection signal emitted by the SQUID device to supply an analogue acquisition signal. The primary detection antenna may be of the volume type, comprising Helmholtz coils or saddle coils, or a more complex volume geometry, particularly gradiometric geometry. The means for processing the secondary detection signal may comprise a flux-locked loop, provided to linearize the response of the SQUID device.

A medical radiofrequency coil may comprise: a base substrate; and a radio coil unit having a first coil element which has a rectangular shape and is formed along an edge of the inner peripheral surface of the base substrate, and a second coil element which is formed at the inner side of the first coil element and has a shape of paired paddles connected to each other. Therefore, the present inventive concept provides a radiofrequency coil, which can minimize an image distortion due to a beam-hardening artifact effect, and a medical imaging device including the same.

An HF coil assembly for generating independent alternating magnetic fields in an examination volume of a magnetic resonance apparatus is presented, the HF coil assembly comprising a first coil pair of saddle coils and a second coil pair of saddle coils, each saddle coil having longitudinal conductor elements and curved conductor elements arranged along a common lateral surface of a circular cylinder having a cylinder axis. Each coil pair comprises curved conductor elements and longitudinal conductor elements which are interconnected at a high frequency. The saddle coils also have diagonal conductor elements and/or bridge elements that connect the longitudinal and curved conductor elements. The coil pairs are opposite to each other relative to the cylinder axis.

This disclosure generally relates to stable water isotope labeling followed by detection via MRI (swiMRI), including deuterium MRI (dMRI) and .sup.17O MRI, for visualizing rapidly dividing immune cells within target and/or lymphoid organ/s and/or tissues affected by chronic graft-versus-host disease (cGVHD). Using deuterated water labeling, followed by dMRI, a distinction in deuterium signal was detected in a target organ (e.g. liver) of the cGVHD-affected mice compared to unaffected mice, i.e. syngeneic HSCT recipient mice, where the host and donor are matched, and normal (unmanipulated) mice.

An electron-nuclear double resonance resonator, having a loop-gap resonator and an elongated lead; the loop-gap resonator comprises a plurality of arc-shaped conductive plates, and the elongated lead connects the arc-shaped conductive plates into a radio-frequency coil; the loop-gap resonator resonates at an electron resonance frequency, and the radio-frequency coil resonates at a nuclear resonance frequency; with the structure of the loop-gap resonator, the separation between an electric field and a magnetic field can be accelerated to ensure the maximization of the ratio of the magnetic field to the electric field inside a resonant resonator; and with the elongated lead, the impact of the lead to a resonance frequency and the mode of the loop-gap resonator is prevented as much as possible, and meanwhile the conductive plates of the loop-gap resonator can be connected into the radio-frequency coil.