Abstract: A multi-modal antenna for use in magnetic resonance applications, the multi-modal antenna including an elongate first conductive element, an elongate second conductive element at least partially aligned with and spaced from the first conductive element and a dielectric material at least partially separating the first and second conducting elements so that the first and second conductive elements are electromagnetically coupled and/or electrically connected, and wherein at least one of the first and second conducting elements are configured to be electromagnetically coupled and/or electrically connected to an RF system so that the multi-modal antenna can at least one of transmit and receive RF electromagnetic signals for performing magnetic resonance imaging or spectroscopy.

Abstract: A superconducting magnet for MRI comprising two magnet assemblies spaced along an axis and producing at least 0.7 Tesla. Each assembly including a primary coil structure (PCS) having at least first and second layers of radially-stacked primary coils and a shielding coil structure (SCS). Each layer including one or more primary coils in parallel to the axis and situated between inner and outer axial ends of the assembly that are closest to and furthest from an imaging region. The first and second layers having primary coils adjacent to the inner axial end. The PCS including a primary coil spaced from the inner axial end. The inner diameter of each primary coil of the second layer being greater than that of each primary coil in the first layer and similar to that of each coil of the SCS. The layers and shielding coil are arranged on three former portions.

Abstract: A magnetic resonance imaging (MRI) system uses a superconducting magnet having a primary coil structure and a shielding coil layer. The primary coil structure comprises at least three sets of coils with significantly different inner diameters, forming a three-bore magnet structure. The three bores are coaxially aligned with a longitudinal axis, with the largest diameter first bore on one side of the magnet and the smallest diameter third bore on another side of the magnet, as well as a medium diameter second bore located axially between the first and the third bores. The first bore allows access for the head and shoulders and permits the head to enter into the second bore for imaging, while the patient's extremities (hands, legs) may access through the third bore for producing images of the extremity joints. The magnet may also be used for other specialist imaging where use of a whole-body MRI is unwarranted, such as the imaging of neonates.

Abstract: A coil arrangement for use in a magnetic resonance imaging system, the imaging system being for generating a magnetic imaging field in an imaging region, the coil arrangement including at least three coils for at least one of transmitting, receiving or transceiving an electromagnetic field, each coil being provided on a coil geometry and being substantially orthogonal.

Abstract: A magnetic resonance imaging (MRI) system uses a superconducting magnet having a primary coil structure and a shielding coil layer. The primary coil structure comprises at least three sets of coils with significantly different inner diameters, forming a three-bore magnet structure. The three bores are coaxially aligned with a longitudinal axis, with the largest diameter first bore on one side of the magnet and the smallest diameter third bore on another side of the magnet, as well as a medium diameter second bore located axially between the first and the third bores. The first bore allows access for the head and shoulders and permits the head to enter into the second bore for imaging, while the patient's extremities (hands, legs) may access through the third bore for producing images of the extremity joints. The magnet may also be used for other specialist imaging where use of a whole-body MRI is unwarranted, such as the imaging of neonates.

Abstract: A coil for a magnetic resonance imaging device consists of multiple coil elements arranged about an imaging space. Each coil element comprise radiating structures oriented at an angle to a tangent of the imaging space. Angling the radiating structures reduces mutual coupling between coil elements and enhances the penetration of the radio frequency field to the imaging space.

Abstract: The invention describes a method that provides a practical means of accurately estimating the electromagnetic fields and therefore the SAR (specific absorption rate) distributions of a subject in magnetic resonance imaging (MRI) scan. The disclosed method consists of several steps. If the coil information is unavailable during the patent imaging, the first step, generally performed before patient (or target) imaging, estimates the geometry of the radiofrequency (RF) coils. The second step estimates the patient-specific tissue volumes by deforming an appropriate reference with known tissue distribution from a database to the said target. Finally, the electromagnetic fields and the SAR distributions are calculated using numerical methods performed on the accurately estimated RF coils and patient-specific tissue volumes. The proposed method can be used for safe, accurate MR imaging at any magnetic field strengths, particular suitable for high-field applications.

Abstract: Apparatus for use in a magnetic resonance imaging system, the imaging system generating a magnetic imaging field in an imaging region (5), the apparatus including at least one coil for at least one of transmitting, receiving or transceiving an electromagnetic field, a field component (4) (such as a coil or a shield) and a drive (6) coupled to the field component for moving the field component (4) relative to the imaging region (5) to thereby modify the electromagnetic field during imaging process. The same concept can also be applied to nuclear imaging or nuclear spectroscopy apparatus.

Abstract: A magnetic resonance system uses a shielded superconducting magnet to produce a dsv useful for specialist imaging in an overall short magnet system at field strengths 1.5 Tesla and above. The magnet includes at least a first central coil C1, which has a length of at least 25% of the overall length of the magnet, and is used in concert with a series of symmetric primary coils, at least one set of which carry current in a direction opposite to that of the central coil. Force balancing is advantageously used in the design of the coils. The primary coils are shielded by at least one shielding coil, which carries current in a direction opposite to the majority of the primary coils. The magnet resonance system can be used for orthopedic imaging.

Abstract: A Magnetic Resonance Imaging (MRI) phased array head coil (10) comprises an array of coils (1, 2, 3, 4) a decoupling circuit (7) and a decoupling base (14). Counter wound inductors from adjoining coils (1, 2, 3, 4) in the decoupling circuit (7) are interlaced to achieve mutual decoupling between adjoining coils. Each separate coil (1, 2, 3, 4) includes a pair of spaced parallel main conductors (12) located on opposite sides of a cylindrical space (5) enclosed by the coils (1, 2, 3, 4). The decoupling base (14) comprises two meandering conductor bases (8, 9) which are interlaced. Orthogonal main conductors (12) of the coil (1, 2, 3, 4) share a common conductor base (8, 9). The multiple crossings of the paths of the conductor bases (8, 9) reduces mutual coupling effects.

Abstract: A magnetic resonance system is provided which employs a shielded, electromagnetically asymmetric and low-stress magnet to produce a superior sized imaging region close to the patient side. The magnet has a double layered configuration. In the primary layer, the magnet includes at least two strongest coils at two ends of the magnet (end coils), which carry current in the same direction. The magnet may include at least one coil close to the end coils which carries current in a direction opposite to that of the end coils. The magnet employs a plurality of smaller sized coils (4-7, relative to the large end-coils) in the central region of the primary layer, and these coils are located asymmetrically relative to the imaging region centre. The magnet is shielded by a plurality (1-5) of shielding coils, which carry current in a direction opposite to that of the end-coils at primary layer.

Abstract: A coil for a magnetic resonance imaging device consists of multiple coil elements arranged about an imaging space. Each coil element comprise radiating structures oriented at an angle to a tangent of the imaging space. Angling the radiating structures reduces mutual coupling between coil elements and enhances the penetration of the radio frequency field to the imaging space.

Abstract: A coil arrangement for use in a magnetic resonance imaging system, the imaging system being for generating a magnetic imaging field in an imaging region, the coil arrangement including at least three coils for at least one of transmitting, receiving or transceiving an electromagnetic field, each coil being provided on a coil geometry and being substantially orthogonal.

Abstract: Apparatus for use in a magnetic resonance imaging system, the imaging system generating a magnetic imaging field in an imaging region (5), the apparatus including at least one coil for at least one of transmitting, receiving or transceiving an electromagnetic field, a field component (4) (such as a coil or a shield) and a drive (6) coupled to the field component for moving the field component (4) relative to the imaging region (5) to thereby modify the electromagnetic field during imaging process. The same concept can also be applied to nuclear imaging or nuclear spectroscopy apparatus.

Abstract: A portable device is used to measure exposure to magnetic fields and/or exposure to changes of magnetic field. The device (10) includes a first sensor (14) for measuring instantaneous magnetic field strength, and a second sensor (15) which is located adjacent to, and orientated in the same direction as, the first sensor for providing an output indicative of the time rate of change of the magnetic field. An integrator (22) integrates the rate of change output from the second sensor (15) over time to derive relative changes in the magnetic field. A processor (20) is connected to the outputs of at least the first sensor and the integrator. The processor selectively provides an indication of field strength from the output of the first sensor if the output is within the normal operating range of the first sensor, or otherwise from the integrator. A memory (24) is connected to the output of the second sensor (15) to store cumulative exposure to changes in the magnetic field.

Abstract: A method and apparatus for ameliorating high-field image distortion in magnetic resonance imaging of tissue. Two separate scans of a target region are taken with different phase and amplitude values for each scan. The phase and amplitude values of each scan are selected to be complimentary so as to provide scans that have improved SNR when averaged using, for example, sum-of-squares averaging.

Abstract: A Magnetic Resonance Imaging (MRI) phased array head coil (10) comprises an array of coils (1, 2, 3, 4) a decoupling circuit (7) and a decoupling base (14). Counter wound inductors from adjoining coils (1, 2, 3, 4) in the decoupling circuit (7) are interlaced to achieve mutual decoupling between adjoining coils. Each separate coil (1, 2, 3, 4) includes a pair of spaced parallel main conductors (12) located on opposite sides of a cylindrical space (5) enclosed by the coils (1, 2, 3, 4). The decoupling base (14) comprises two meandering conductor bases (8, 9) which are interlaced. Orthogonal main conductors (12) of the coil (1, 2, 3, 4) share a common conductor base (8, 9). The multiple crossings of the paths of the conductor bases (8, 9) reduces mutual coupling effects.

Abstract: A magnetic resonance system uses a shielded superconducting magnet to produce a dsv useful for specialist imaging in an overall short magnet system at field strengths 1.5 Tesla and above. The magnet includes at least a first central coil C1, which has a length of at least 25% of the overall length of the magnet, and is used in concert with a series of symmetric primary coils, at least one set of which carry current in a direction opposite to that of the central coil. Force balancing is advantageously used in the design of the coils. The primary coils are shielded by at least one shielding coil, which carries current in a direction opposite to the majority of the primary coils. The magnet resonance system can be used for orthopedic imaging.

Abstract: A method and apparatus for ameliorating high-field image distortion in magnetic resonance imaging of tissue. Two separate scans of a target region are taken with different phase and amplitude values for each scan. The phase and amplitude values of each scan are selected to be complimentary so as to provide scans that have improved SNR when averaged using, for example, sum-of-squares averaging.

Abstract: A radio frequency (RF) coil array is used in resonance imaging and/or analysis of a subject located within a cylindrical space in which a magnetic field is operatively applied in an axial direction (z). The coil array comprises a plurality of coil elements (10, 11, 12, 13) angled relative to each other about the axis of the cylindrical space, each coil element having a pair of main conductors extending generally parallel to the direction of the magnetic field and located on diametrically opposite sides of the cylindrical space, and a pair of connection conductors connected between respective ends of the main conductors. Each coil element has its maximum sensitivity near the centre of the cylindrical space, so that the subject under study is located in a region of maximum sensitivity.