Abstract: An ultra-high field radio-frequency (RF) transmit/receive apparatus radio-frequency (RF) transmit/receive apparatus for magnetic resonance (MR) systems, may include: a dipole-array based volume coil (2) with a plurality of straight dipole antennas (3); at least three circular conducting rings (4, 5, 6) radial surrounding the dipole-array based volume coil (2), the at least three circular conducting rings (4, 5, 6) being substantially parallel with each other, having a plurality of ports (9, 10) for receiving a set of quadrature drive signals, the RF coil apparatus further comprising at least two independent transmit/receive (T/R) RF channels (11, 12, 13, 14) for driving the dipole-array based volume coil (2) and the at least three circular conducting rings (4, 5, 6).

Abstract: An ultra-high field radio-frequency (RF) transmit/receive apparatus radio-frequency (RF) transmit/receive apparatus for magnetic resonance (MR) systems, may include: a dipole-array based volume coil (2) with a plurality of straight dipole antennas (3); at least three circular conducting rings (4, 5, 6) radial surrounding the dipole-array based volume coil (2), the at least three circular conducting rings (4, 5, 6) being substantially parallel with each other, having a plurality of ports (9, 10) for receiving a set of quadrature drive signals, the RF coil apparatus further comprising at least two independent transmit/receive (T/R) RF channels (11, 12, 13, 14) for driving the dipole-array based volume coil (2) and the at least three circular conducting rings (4, 5, 6).

Abstract: An apparatus (100) comprises at least one electronic processor (101, 113) programmed to: control an associated medical imaging device (120) to acquire an image (130); compute values of textural features (132) for the acquired image; generate a signature (140) from the computed values of the textural features; and at least one of: display the signature on a display device (105); and apply an artificial intelligence (AI) component (150) to the generated signature to output image artifact metrics (152) for a set of image artifacts and display an image quality assessment based on the image artifact metrics on the display device.

Abstract: A method of operating a magnetic resonance imaging system (10) includes adjusting a radio frequency excitation field B1 to be applied to a subject of interest (20) to be imaged. At least one position parameter (d) that is indicative of a position of at least the portion of the subject of interest (20) relative to at least one radio frequency transmit antenna (36) of the magnetic resonance imaging system (10) is determined. At least one radio frequency power-related parameter of radio frequency power to be fed to the at least one radio frequency transmit antenna (36) is adjusted in dependence of the at least one of the determined at least one position parameter (d) and a determined geometric dimension (w) of the subject of interest (20).

Abstract: The present invention provides a RF coil assembly comprising a first rigid frame and a flexible coil in a naturally planar shape having a first end, a second end opposite the first end and a longitudinal axis extending from the first end to the second end. The first end of the flexible coil is attached to the first rigid frame and the second end of the flexible coil is away from the first rigid frame. The first rigid frame is shaped to bend the flexible coil, upon attaching the first end of the flexible coil to the first rigid frame, to form a shape of the RF coil assembly which conforms to a shape of a region of a subject with multiple contours. According to the present invention, the RF coil assembly is lighter and better matches the regions of different subjects to be imaged. The contoured shape of the RF coil assembly can be maintained for immediate use instead of having to achieve the shape by an operator attaching the flexible coil to body regions.

Abstract: The invention relates to a magnetic resonance imaging (MRI) system with emergency quench.

Abstract: In a magnetic resonance examination system, the patient carrier is mounted moveably in a direction transverse to the support surface and an RF antenna has a fixed geometrical relation to the support surface.

Abstract: A therapeutic apparatus comprising a radiotherapy apparatus for treating a target zone and a magnetic resonance imaging system for acquiring magnetic resonance imaging data. The radiotherapy apparatus comprises a radiotherapy source for directing electromagnetic radiation into the target zone. The radiotherapy apparatus is adapted for rotating the radiotherapy source at least partially around the magnetic resonance magnet. The magnetic resonance imaging system further comprises a radio-frequency transceiver adapted for simultaneously acquiring the magnetic resonance data from at least two transmit-and-receive channels. The therapeutic apparatus further comprises a processor and a memory containing machine executable instructions for the processor.

Abstract: The invention relates to a magnetic resonance imaging (MRI) system with emergency quench.

Abstract: The invention provides for a magnetic resonance imaging system (100) comprising: a magnet (104) for generating a main magnetic field with an imaging zone (110), and a gradient coil system (110, 112). The gradient coil system comprises a set of unshielded gradient coils (110). The magnetic resonance imaging system further comprises a processor (130) for controlling the magnetic resonance imaging system. Execution of the instructions stored in a memory cause the processor to: acquire (200, 304) imaging magnetic resonance data (152) from a volume (109) within the imaging zone using a zero echo time pulse sequence; reconstruct (202, 306) a three-dimensional image (156) using the imaging magnetic resonance data; subtract a calibration image from the three-dimensional image, the calibration image having been acquired without a subject in the imaging zone; and render the three-dimensional image on a display by projecting it on a two-dimensional plane.

Abstract: The invention provides for a magnetic resonance imaging system (100) for acquiring magnetic resonance data (142, 144) from an imaging zone (108).

Abstract: The invention relates to a method of MR imaging of an object positioned in an examination volume of a MR device (1). It is an object of the invention to enable ‘silent’ ZTE imaging with sampling of k-space center. According to the invention, the object (10) is subjected to an imaging sequence of RF pulses (20) and switched magnetic field gradients (G), wherein an initial RF pulse (20) is radiated before setting a readout magnetic field gradient (G). An initial MR signal is acquired with the readout magnetic field gradient (G) ramping up after a delay after the initial RF pulse (20). Thereafter, the magnetic field gradient (G) remains switched on and the readout direction is gradually varied. Further RF pulses (22) are radiated in the presence of the readout magnetic field gradient (G) and further MR signal are acquired like in conventional ZTE imaging. Finally, a MR image is reconstructed from the acquired MR signals. Moreover, the invention relates to a MR device and to a computer program for a MR device.

Abstract: A birdcage resonator (109) for MR imaging, surrounds an examination volume and includes a plurality of rungs (1-16) arranged in parallel to a longitudinal axis of the examination volume. Each rung (1-16) includes a rung capacitance (Crung). Two end rings are arranged at the opposite ends of the rungs (1-16), each end ring includes a plurality of ring capacitances (Cring). Each ring capacitance (Cring) interconnects a pair of adjacent rungs (1-16). Each pair of adjacent rungs and the interconnecting ring capacitances (Cring) form a mesh of the birdcage resonator. The ring capacitances (Cring) and the rung capacitances (Cring) are proportioned so that: —the birdcage resonator (109) has a plurality of resonant modes that are tuned to the same resonance frequency, and the meshes of the birdcage resonator (109) are electromagnetically coupled. An MR device (101) includes the birdcage resonator.

Abstract: A magnetic resonance examination system in which the patient carrier is mounted moveably in a direction transverse to the support surface and an RF antenna having a fixed geometrical relation to the support surface.

Abstract: Coil elements (18) generate a B1 excitation field in an examination region (14), which B1 excitation field is distorted by patient loading (e.g., wavelength effects). Passive shimming elements (22, 24) are disposed between the coil elements and the subject in order to improve the B1 field uniformity. In one embodiment, passive shimming elements include one or more dielectric rods (55) disposed below the subject which generate no substantial MR proton signal and which have a permittivity of at least 100 and preferably greater than 500. In another embodiment, tubes (24) adjacent each coil element are supplied with a dielectric liquid, a thickness of the dielectric liquid between the coil element and the subject adjusting a phase of the B1 field generated by the coil element. Active B1 shimming may be combined with passive shimming elements (22, 24) to effect an improved RF field homogeneity result.

Abstract: A magnetic resonance method of electric properties tomography imaging of an object includes applying an excitation RF field to the object via a coil at a first spatial coil position (402), acquiring resulting magnetic resonance signals via a receiving channel from the object, determining from the acquired magnetic resonance signals a first phase distribution and a first amplitude of a given magnetic field component of the excitation RF field of the coil at the first coil position (402), repeating these steps with a coil at a second different spatial coil position (404), to obtain a second phase distribution, determining a phase difference between the first and second phase distribution, determining a first and a second complex permittivity of the object, the first complex permittivity comprising the first amplitude of the given magnetic field component and the second complex permittivity comprising the second amplitude of the given magnetic field component and the phase difference, equating the first complex

Abstract: The invention provides for a magnetic resonance imaging system (100) for acquiring magnetic resonance data (142, 144) from an imaging zone (108).

Abstract: A method of operating a magnetic resonance imaging system (10) with regard to adjusting a radio frequency excitation field B1 to be applied to a subject of interest (20) to be imaged, the method comprising steps of—determining at least one position parameter (d) that is indicative of a position of at least the portion of the subject of interest (20) relative to at least one radio frequency transmit antenna (36) of the magnetic resonance imaging system (10); and—adjusting at least one radio frequency power-related parameter of radio frequency power to be fed to the at least one radio frequency transmit antenna (36) in dependence of at least one out of the determined at least one position parameter (d) and a determined geometric dimension (w) of the subject of interest (20); and—a magnetic resonance imaging system (10) having a proximity detection unit (46), including at least one proximity detector (D), and a control unit (26), wherein the control unit (26) is configured to carry out steps of such a method.

Abstract: The invention relates to a multi-channel (e.g. quadrature) MRI transmit system in which RF power amplifiers having different power capabilities are used in different transmit channels. This results in reduced system costs, due to the avoidance of an unused excess of RF power capability when the power demand for obtaining a homogeneous B1-field (RF shimming) is asymmetric and the asymmetry is qualitatively the same for different imaging applications. The multi-channel transmit unit may also comprise a commutator which enables to selectively connect each RF power amplifier to each drive port of transmit coil arrangement (e.g. a birdcage coil).

Abstract: The invention relates to a method of MR imaging of at least a portion of a body (110) of a patient placed in an examination volume of a MR device, the method comprising the steps of:—subjecting the portion of the body (110) to an imaging sequence comprising at least one RF pulse, the RF pulse being transmitted toward the portion of the body (110) via a RF coil arrangement (109) to which RF signals are supplied by two or more RF power amplifiers the RF power amplifiers being activated alternately during the imaging sequence in a time-multiplexed fashion, wherein the imaging sequence requires a RF duty cycle and/or a RF pulse duration exceeding the specification of at least one of the RF power amplifiers;—acquiring MR signals from the portion of the body (110); and—reconstructing a MR image from the acquired MR signals. Moreover, the invention relates to a method of MR spectroscopy involving the alternating use of RF power amplifiers in a time-multiplexed fashion.