A head coil apparatus for MRI of a person's head includes a transmit coil array device generating RF fields for spin state excitation to the head, wherein the transmit coil array device comprises multiple transmit coil loops decoupled from each other and arranged on a transmit coil array carrier surrounding an inner head coil space for receiving the head; a receive coil array device for receiving RF resonance signals from the head; a RF shield surrounding the transmit coil array device and the receive coil array device; and a head coil window providing a viewing port through the RF shield and transmit coil array device. The head coil window has a longitudinal extension and an azimuthal extension, the transmit coil loops includes a window coil loop surrounding the head coil window, and the coil loop is decoupled from a neighbouring transmit coil loop by sharing a common loop conductor.

Various embodiments of the present disclosure are directed towards a magnetic resonance imaging (MRI) radio frequency (RF) coil array configured to operate in at least one of a transmit mode or a receive mode on a cylindrical former. The MRI RF coil array includes at first row of RF coil elements. Each row of RF coil elements includes at least three RF coil elements that circumferentially surround a cylindrical axis. The MRI RF coil array also includes a first birdcage coil that circumferentially surrounds the first row of RF coil elements. Each RF coil element of the first row is configured to inductively couple to the first birdcage coil and to each other RF coil elements. The first birdcage coil has an impedance configured to negate inductive coupling between the RF coil elements of the first row.

The invention relates to a local coil matrix and to a magnetic resonance scanner for operation by means of a low magnetic field. The local coil matrix according to the invention has a first coil winding and a second coil winding and a first low-noise pre-amplifier and second pre-amplifier, each electrically connected to a coil winding. The first coil winding has a broadband matching in a first frequency range at a Larmor frequency to the first pre-amplifier connected thereto.

A radio frequency coil according to an embodiment configured to receive a magnetic resonance signal from a subject by a plurality of coil elements including a first coil element and a second coil element. The first coil element and the second coil element are supported by a first housing and a second housing, the first housing and the second housing being rigid. The first housing and the second housing are connected by a flexible connector. The first coil element overlaps the second coil element at least part of the connector.

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.

Various embodiments of the present disclosure are directed towards a radio frequency (RF) coil comprising a first combination coil and a second combination coil. The first combination coil comprises a first resonant coil and a first resonant shield coupled inductively or by a capacitor, and the first combination coil has a first resonant frequency and a second resonant frequency. The second combination coil comprises a second resonant coil and a second resonant shield coupled inductively or by a capacitor, and the second combination coil has a third resonant frequency and a fourth resonant frequency. The first and second resonant coils are inductively coupled to each other and respectively to the second and first resonant shields. The first and third resonant working frequencies are the same, and the second and fourth resonant isolation frequencies are such that inductive coupling between the first and second resonant coils is negated.

A local coil includes a coil element in the form of a loop. The coil element includes a first conductor, a second conductor, and a third conductor. The coil element includes a first dielectric and a second dielectric. The first dielectric is arranged between the first conductor and the second conductor, and the second dielectric is arranged between the second conductor and the third conductor. The coil element includes a receive unit that includes the first conductor and the second conductor, and a detuning unit that includes the third conductor. In a first operating state of the coil element, the receive unit has a first resonant frequency. In a second operating state of the coil element, the detuning unit is configured to detune the resonant frequency of the receive unit so that the receive unit has a second resonant frequency different than the first resonant frequency.

A radio frequency coil according to an embodiment is configured to receive a magnetic resonance signal from an examined subject. The radio frequency coil includes an expandable and contractible first element and an expandable and contractible second element. The radio frequency coil has an overlap region where a first loop formed by the first element overlaps with a second loop formed by the second element. The ratio of the area of the overlap region to the area of the region enclosed by the first loop changes in accordance with expansion/contraction of the first element forming the first loop. The first element and the second element include liquid metal in at least a part thereof.

A self-decoupled RF coil and method for adjusting the same is disclosed. The RF coil is an array of elements including at least one loop. Electromagnetic coupling between elements in the array causes an induced current in the at least one loop. The induced current has two modes. A reactance inserted in the at least one loop balances the two modes. The balanced current modes cancel. This cancelation results in self-decoupling of at the least one loop from the other elements in the RF coil array.

Methods and systems are provided for radio frequency (RF) coil arrays for magnetic resonance imaging (MRI) systems. In an embodiment, a RF coil array assembly for a MRI system includes a compressible body; an upper posterior RF coil array including a first plurality of RF coils embedded in the compressible body; a lower posterior RF coil array including a second plurality of RF coils embedded in the compressible body; and a head and neck RF coil array removably coupled to the upper posterior RF coil array. The head and neck RF coil array includes a third plurality of RF coils embedded in the compressible body, and one or more neck straps configured to fold over a neck of a subject to be imaged by the MRI system.