Embodiments relate to multi-turn magnetic resonance imaging (MRI) radio frequency (RF) coil arrays employing ring decoupling, and MRI apparatuses employing such coil arrays. One example embodiment comprises: four or more RF coil elements that enclose a cylindrical axis, wherein each RF coil element comprises a first capacitor of that RF coil element and a loop comprising at least two turns; and a ring structure that facilitates decoupling of the RF coil elements, wherein each RF coil element is adjacent to two neighboring RF coil elements and is non-adjacent to one or more other coil elements, wherein each RF coil element has a shared side in common with the ring structure, wherein the shared side comprises a second capacitor of that RF coil element with a capacitance selected to mitigate inductive coupling between that RF coil element and non-adjacent RF coil elements.

PET or SPECT insert for MRI or MRS system with medium (3 T for example) to ultra high (7 T for example) magnetic field is provided. RF shielded radiation detector modules are separately disposed in a form of full or partial ring shape. The RF shielded radiation detector modules are electric ground conductors for microstrip transmission line coil RF array. Decoupling circuits in between grounded shield and/or in between microstrip conductors make electric isolation between coil elements.

Various methods and systems are provided for a flexible, lightweight, low-cost radio frequency (RF) coil array of a magnetic resonance imaging (MRI) system. In one example, a RF coil assembly for a MRI system includes a loop portion comprising distributed capacitance wire conductors, a coupling electronics portion including a pre-amplifier. A coupler slidably connects two adjacent coil loops together. An open area is formed inside the loops enabling tissue manipulation or biopsies from interventional or surgical procedures.

A dipole antenna assembly includes at least two dipole antennas mechanically, but not electrically, connected to each other. The at least two dipole antennas cross at an intersection point and form dipole antenna arms starting from the intersection point. The dipole antenna arms are arranged in a half-space.

A magnetic resonance imaging apparatus according to an embodiment includes a receiver array coil structured with a plurality of receiver coils. Each of the receiver coils included in the receiver array coil includes a coil element, a first tuning element configured to tune a tunable frequency of the receiver coil to a desired frequency, and a series circuit including a switching element and a second tuning element and being connected in parallel with the first tuning element. The switching element is configured to disconnect the first tuning element and the second tuning element from each other at the time of transmitting and is configured to arrange the first tuning element and the second tuning element to be electrically conductive with each other at the time of receiving. At least two receiver coils positioned adjacent to each other among the plurality of receiver coils are decoupled from each other.

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 head coil assembly includes a housing with a lower portion, an upper portion, a left portion, and a right portion, wherein each portion includes two or more radio-frequency (RF) coils, wherein the portions are sized and shaped to adjustably conform to a curvature of the subject's head for magnetic resonance (MR) imaging of the subject's head placed inside the housing, wherein the portions are operable to transition from an open position where the portions are sufficiently apart from each other to a closed position where the portions are adjusted to tighten a wrap around the subject's head along the curvature, and wherein the two or more RF coils in each portion are disposed in such manner that when the portions are operated to transition from the open position to the closed position, the RF coils of each portion remain decoupled to each other even along edges of each portion.

An example magnetic resonance imaging (MRI) radio frequency (RF) coil array comprises: at least one row of RF coil elements arranged radially around a cylindrical axis, wherein each row comprises: at least four RF coil elements circumferentially enclosing the cylindrical axis, wherein each RF coil element of that row is configured to operate in a Tx mode and in a Rx mode, wherein, in the Rx mode, each RF coil element of that row is tuned to a working frequency of the MRI RF coil array, and wherein, in the Tx mode, each RF coil element of that row is tuned to an additional frequency that is different than the working frequency, wherein the additional frequency is such that, a mode frequency of a selected mode resulting from coupling among the RF coil elements of that row is at the working frequency.

In one example, an RF coil array includes a first RF coil configured to generate a magnetic field along a first axis, the first RF coil having a first surface, a second RF coil configured to generate a magnetic field along a second axis, orthogonal to the first axis, the second RF coil having a second surface, and a first foldable interconnect coupling the first RF coil to the second RF coil. The first foldable interconnect may be adjusted to couple the first RF coil to the second RF coil with a first amount of overlap and with the first surface and second surface facing a common direction, or couple the first RF coil to the second RF coil with a second amount of overlap, larger than the first amount of overlap, and with the first surface in face to face position with the second surface.

An MRI RF coil array for use in a multi-channel MRI system, comprising a plurality of coils arranged in a M by N array, the number of columns corresponding with the number of channels in the MRI system. Columns are aligned with the B.sub.0 field. The plurality of coils are configured as a plurality of combined coils, corresponding with the number of columns, comprising a coil in a first row of the array connected with a coil in each of the remaining rows. The column position of each coil of a combined coil is distinct from the column position of each other coil of the combined coil. Coils of a combined coil are disjoint from the coils of each, other, combined coil. A combined coil is configured to connect with a corresponding member of the plurality of Rx channels, and is decoupled from each, other combined coil.