The present invention provides a radio frequency (RF) coil (140) for applying an RF field to an examination space (116) of a magnetic resonance (MR) imaging system (110) and/or for receiving MR signals from the examination space (116), whereby the RF coil (140) is provided having a tubular body (142), the RF coil (140) is segmented in a longitudinal direction (154) of the tubular body (142) into two coil segments (146), and the two coil segments (146) are spaced apart from each other in the longitudinal direction (144) of the tubular body (142), whereby a gap (148) is formed between the two coil segments (146). The present invention further provides a magnetic resonance (MR) imaging system (110) comprising at least one radio frequency (RF) coil (140) as specified above. The present invention still further provides a medical system (200) comprising the above magnetic resonance (MR) imaging system (110) and a medical device (202), which is arranged to access to the examination space (116) of the magnetic resonance (MR) imaging system (110) through the gap (148) of the RF coil (140). Even further, the present invention provides a method for applying a radio frequency (RF) field to an examination space (116) of a magnetic resonance (MR) imaging system (110), comprising the steps of providing at least one above radio frequency antenna device (140), and commonly controlling the two RF coil segments (146) to provide a homogenous B.sub.1 field within the examination space (116), in particular within the gap (148).

A method and apparatus for receiving (RX) radio-frequency (RF) signals suitable for MRI and/or MRS from a plurality of MRI “coil elements” (antennae), each contained in one or a plurality of body-coil parts, wherein the body-coil parts are easily assemble-able into a body-coil assembly (e.g., in some embodiments, a cylindrical body-coil assembly) with shield elements that are overlapped and/or concentric, and wherein the body-coil assembly is readily disassemble-able for easier shipping, and wherein the body-coil parts are optionally usable individually as transmit (TX) and/or receive (RX) coil elements for MRI. In some embodiments, the system provides for repeatable assembly and disassembly for ease of maintenance (such as frequency tuning and impedance matching) such that the body-coil assembly can be fully assembled and tested, then taken apart for less costly and easier shipping (with reduced risk of damage) and then reassembled at the destination for operation in an MRI system.

The present invention provides a radio frequency (RF) shield device (124) for a magnetic resonance (MR) examination system (110), whereby the RF shield device (124) comprises a first shield (250) and a second shield (252), the first shield (250) and the second shield (252) are arranged with a common center axis (118), the first shield (250) has a shield structure (254) different from a shield structure (254) of the second shield (252), and the first shield (250) and the second shield (252) are designed in accordance with different modes of operation of a RF coil device (140). The present invention also provides a radio frequency (RF) coil device (140) for a magnetic resonance (MR) examination system (110), whereby the RF coil device (140) comprises a first coil (200) and in a second coil (202), the first coil (200) and the second coil (202) are provided as birdcage coils, the first coil (200) and the second coil (202) are arranged with a common center axis (118), the first coil (200) and the second coil (202) have rungs (204), which are arranged non-parallel to the center axis (118) of the RF coil device (140), the first coil (200) has a coil structure (210) different from a coil structure (210) of the second coil (202), and the first coil (200) and the second coil (202) are switchable to be active for different modes of operation. The present invention further provides a magnetic resonance (MR) imaging system (110), comprising such a RF coil device (140) and/or such a RF shield device (124).

A TEM RF antenna device (40) for a magnetic resonance MR imaging system (10), ⋅the RF antenna device (40) comprising a plurality of rungs (44), and each rung (44) having at least one axial member (46) that in an operational state is substantially arranged parallel to the axial direction (38) wherein ⋅the axial members (46) of the plurality of rungs (44) are arranged along an azimuthal direction (34) in a substantially equally spaced relationship about a center axis (42), and wherein ⋅the at least one axial member (46) of each of the rungs (44) has two end regions (48, 50) and wherein ⋅for at least two rungs (44′, 44″) of the plurality of rungs (44) that are adjacently arranged with regard to the azimuthal direction (34), each rung (44′, 44″) comprising at least one transversal member (52, 54) that is galvanically connected to one of the end regions (48, 50) of the axial member (46) of that rung (44′, 44″) only, in the operational state, the at least one transversal members (52, 54) of the adjacent rungs (44′, 44″) are substantially arranged such that there exists at least one location on each of the transversal members (52, 54) of the two rungs (44′, 44″) that at least have substantially identical azimuthal coordinates, thereby reducing the RF field outside of the antenna device.

A radio frequency transmit system (40) for use in magnetic resonance imaging apparatuses, comprising a radio frequency driver unit (42) including at least a first radio frequency power source (44; 82) and a second radio frequency power source (46; 84), a radio frequency coil arrangement (48) for generating an RF magnetic excitation field B.sub.1, and a plurality of switching members (68, 70, 72, 74) electrically connecting the radio frequency power sources (44, 46; 82, 84) to different pairs of drive ports (58, 60, 62, 64) in a first and in at least a second switching status. The first drive port (58) of the first pair of drive ports (58, 60) and the first drive port (62) of the at least second pair of drive ports (62, 64) are arranged spaced by a fixed predetermined angular distance in the azimuthal direction (56) about the center axis (50); and a magnetic resonance imaging system (10) including such radio frequency transmit system (40).

A method and apparatus for receiving (RX) radio-frequency (RF) signals suitable for MRI and/or MRS from a plurality of MRI coil elements (antennae), each contained in one or a plurality of body-coil parts, wherein the body-coil parts are easily assemble-able into a body-coil assembly (e.g., in some embodiments, a cylindrical body-coil assembly) with shield elements that are overlapped and/or concentric, and wherein the body-coil assembly is readily disassemble-able for easier shipping, and wherein the body-coil parts are optionally usable individually as transmit (TX) and/or receive (RX) coil elements for MRI. In some embodiments, the system provides for repeatable assembly and disassembly for ease of maintenance (such as frequency tuning and impedance matching) such that the body-coil assembly can be fully assembled and tested, then taken apart for less costly and easier shipping (with reduced risk of damage) and then reassembled at the destination for operation in an MRI system.

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.

A method and apparatus for receiving (RX) radio-frequency (RF) signals suitable for MRI and/or MRS from a plurality of MRI coil elements (antennae), each contained in one or a plurality of body-coil parts, wherein the body-coil parts are easily assemble-able into a body-coil assembly (e.g., in some embodiments, a cylindrical body-coil assembly) with shield elements that are overlapped and/or concentric, and wherein the body-coil assembly is readily disassemble-able for easier shipping, and wherein the body-coil parts are optionally usable individually as transmit (TX) and/or receive (RX) coil elements for MRI. In some embodiments, the system provides for repeatable assembly and disassembly for ease of maintenance (such as frequency tuning and impedance matching) such that the body-coil assembly can be fully assembled and tested, then taken apart for less costly and easier shipping (with reduced risk of damage) and then reassembled at the destination for operation in an MRI system.

The present invention provides a radio frequency (RF) shield device (124) for a magnetic resonance (MR) examination system (110), whereby the RF shield device (124) comprises a first shield (250) and a second shield (252), the first shield (250) and the second shield (252) are arranged with a common center axis (118), the first shield (250) has a shield structure (254) different from a shield structure (254) of the second shield (252), and the first shield (250) and the second shield (252) are designed in accordance with different modes of operation of a RF coil device (140). The present invention also provides a radio frequency (RF) coil device (140) for a magnetic resonance (MR) examination system (110), whereby the RF coil device (140) comprises a first coil (200) and in a second coil (202), the first coil (200) and the second coil (202) are provided as birdcage coils, the first coil (200) and the second coil (202) are arranged with a common center axis (118), the first coil (200) and the second coil (202) have rungs (204), which are arranged non-parallel to the center axis (118) of the RF coil device (140), the first coil (200) has a coil structure (210) different from a coil structure (210) of the second coil (202), and the first coil (200) and the second coil (202) are switchable to be active for different modes of operation. The present invention further provides a magnetic resonance (MR) imaging system (110), comprising such a RF coil device (140) and/or such a RF shield device (124).

A transverse-electromagnetic (TEM) radio-frequency coil (1) for a magnetic resonance system, especially for a magnetic resonance imaging system, includes a coil (1) in which at least one of the opposite end regions of the elongate strip section (4) of each TEM coil element (2) has a lateral extension (6) transverse to a longitudinal extent of the strip section (4). These lateral extensions (6) combine with strip sections (4) to form L- or U-shaped TEM coil elements (2) and provide ring-like current contributions resulting in a reduction of the z-sensitivity compared with a conventional TEM coil. The result is a coil array having TEM coil elements (2) that provide smaller sensitivity profiles in the z-direction, yet preserve the characteristics of a well-defined RF ground, e.g. via an RF shield or screen (3). The reduced field of view in z-direction not only reduces noise reception but also reduces the SAR generated in those regions during transmission.