Abstract: The invention relates to a method of MR imaging of an object (10) positioned in an examination volume of a MR device (1). It is an object of the invention to enable efficient spiral MR imaging even in situations of strong Bo inhomogeneity. The method of the invention comprises: subjecting the object (10) to an imaging sequence comprising at least one RF excitation pulse and sinusoidally modulated magnetic field gradients, acquiring MR signals along two or more spiral k-space trajectories (31, 32, 33) as determined by the sinusoidal modulation of the magnetic field gradients, wherein the origins of the spiral k-space trajectories are offset from each other, and reconstructing an MR image from the acquired MR signals. Moreover, the invention relates to a MR device (1) and to a computer program for a MR device (1).

Abstract: A magnetic resonance examination method comprises acquisition of a set of magnetic resonance signals from magnetic spins in an object by way of a receiver antenna, the magnetic resonance signals' signal levels are related to an independent reference level that is independent of the receiver antenna's sensitivity to form a calibrated signal level of the magnetic resonance signals, the calibrated signal levels are recorded in terms of a relative density of ordered transverse spins (DOTS). The independent reference level may be derived from the signal-to-thermal-noise ratio. The calibrated signal level in terms of DOTS in ?M/T reflects predominantly a tissue property (of (a voxel of) the patient to be examined) as well as details or characteristics of the acquisition sequence used.

Abstract: The invention relates to a method of MR imaging of an object (10) positioned in an examination volume of a MR device (1). It is an object of the invention to enable efficient spiral MR imaging without blurring artefacts, even in situations of strong B0 inhomogeneity. The method of the invention comprises the following steps: —subjecting the object (10) to an imaging sequence comprising at least one RF excitation pulse and modulated magnetic field gradients, —acquiring MR signals along two or more planar spiral k-space trajectories (31, 32, 33), wherein the radial k-space speed, i.e. the rate of variation of the radial distance from the spiral origin is essentially constant along each planar spiral k-space trajectory, and wherein the two or more k-space trajectories (31, 32, 33) are offset in-plane from each other, and—reconstructing an MR image from the acquired MR signals. Moreover, the invention relates to a MR device (1) and to a computer program for a MR device (1).

Abstract: Disclosed herein is a medical system (100, 300, 500) comprising: a memory (110) storing machine executable instructions (120) and a processor (104).

Abstract: The invention relates to a method of MR imaging of an object (10) positioned in an examination volume of an MR device (1). It is an object of the invention to enable spiral MR imaging with a reduced level of ringing artefacts close to strong local IC main magnetic field inhomogeneity. The method of the invention comprises the following steps: —generating a spin echo by subjecting the object (10) to an imaging sequence comprising an RF excitation pulse (31) followed by an RF refocusing pulse (32), wherein a modulated readout magnetic field gradient (34) is applied subsequent to the RF refocusing pulse (32), —acquiring MR signal data by recording the spin echo along a spiral trajectory in k-space, wherein the waveform of the readout magnetic field gradient (34) defining the spiral trajectory starts before the spin echo center (33), and —reconstructing an MR image from the acquired MR signal data. Moreover, the invention relates to an MR device (1) and to a computer program for an MR device (1).

Abstract: A method of magnetic resonance (MR) imaging includes a phantom that is inexpensive to produce and enables simple, practical and fast assessment of image sharpness, in particular for checking image quality of MR imaging with spiral acquisition. The method includes subjecting a phantom, which comprises a volume filled with a bulk of granules of solid material surrounded by a liquid, to an imaging sequence, acquiring MR signals from the phantom, reconstructing an MR image from the acquired MR signals, and deriving a measure of the local image sharpness in two or more different image regions from the MR image, wherein each image region is a representation of a part of the phantom volume.

Abstract: The invention relates to a method of MR imaging of an object (10) positioned in an examination volume of a MR device (1). It is an object of the invention to enable fast spiral MR imaging with a defined T2 contrast.

Abstract: A B0-mapping method determines the spatial distribution of a static magnetic field in a pre-selected imaging zone comprising computation of the spatial distribution of a static magnetic field from a spatial distribution of spin-phase accruals between magnetic resonance echo signals from the imaging zone and an estimate of the proton density distribution in the imaging zone. The invention provides the field estimate also in cavities and outside tissue. Also the field estimate of the invention suffers less from so-called phase-wraps.

Abstract: The present invention provides a radio frequency (RF) receive coil device for use in a magnetic resonance (MR) imaging system, comprising a RF receive coil, a plug for connecting the RF receive coil to the MR imaging system, sensing means for sensing the presence of a magnetic field of the MR imaging system, detecting means for detecting if the plug is connected to the MR imaging system, and a warning means for generating a warning when the sensing means sense the presence of a magnetic field of the MR imaging system and the detecting means detect that the plug is not connected to the MR imaging system.

Abstract: A cryogenic cooling system (10) comprising a cryostat (12), a two-stage cryogenic cold head (24) and at least one thermal connection member (136; 236; 336; 436) that is configured to provide at least a portion of a heat transfer path (138; 238; 338; 438) from the second stage member (30) to the first stage member (26) of the two-stage cryogenic cold head (24). The heat transfer path (138; 238; 338; 438) is arranged outside the cold head (24). A thermal resistance of the provided at least portion of the heat transfer path (138; 238; 338; 438) at the second cryogenic temperature is larger than a thermal resistance of the provided at least portion of the heat transfer path (138; 238; 338; 438) at the first cryogenic temperature.

Abstract: A method of MR imaging of a body (10) of a patient reduces contrast blurring in PROPELLER imaging combined with multi-echo acquisitions.

Abstract: A magnetic resonance imaging system (200, 300, 400) includes a radio-frequency system (216, 214) with multiple coil elements (214) for acquiring magnetic resonance data (264) and a memory (250) for storing machine executable instructions (260) and pulse sequence commands (262). The pulse sequence commands are configured for controlling the magnetic resonance imaging system to acquire the magnetic resonance data according to a SENSE imaging protocol.

Abstract: A magnetic resonance imaging system includes a gradient system and a processor for controlling the magnetic resonance imaging system.

Abstract: The invention provides for a magnetic resonance imaging system (100, 300) comprising: a radio-frequency system (116, 122, 124, 126, 126?, 126?, 126??) for acquiring magnetic resonance data (152) from an imaging zone (108), wherein the radio-frequency system comprises multiple antenna elements (126, 126?, 126?, 126??); a memory (140) containing machine executable instructions (170) and pulse sequence commands (150), wherein the pulse sequence commands cause the processor to acquire magnetic resonance data from the multiple antenna elements according to a SENSE protocol; and a processor.

Abstract: A magnetic resonance examination system is disclosed comprising a field probe system to measure the magnetic field distribution of the main magnetic field and gradient magnetic field. The measurements are made in an earlier configuration and yield the resultant magnetic field due to gradient switching or external causes. From the measured resultant magnetic field the response relation is derived and stored in the memory. The response relation from the memory is available for compensating activation of the gradient fields or correction in reconstruction for the response relation in reconstruction. This compensation or correction can be carried-out in a current configuration. Thus is the current configuration to field probes are needed.

Abstract: The present invention relates to a method for side-band suppression in a Magnetic Resonance imaging, MRI, system (100), the method comprising providing a first multiband RF pulse for simultaneously exciting at least two slices in a subject (118) at a first and a second frequency band (301,303) and to acquire using the MRI system (100) signals (307, 308) from the excited two slices and at least one additional signal (309) at a third frequency band (305), the additional signal (309) resulting from a sideband excitation of a slice different from the two slices; using the first multiband RF pulse for determining the additional signal (309); deriving a pre-compensating term from the first multiband RF pulse and the additional signal (309), adding the pre-compensating term to the first multiband RF pulse to obtain a second multiband RF pulse, thereby replacing the first multiband RF pulse by the second multiband RF pulse for suppressing at least part of the additional signal (309).

Abstract: The present invention provides a radio frequency (RF) receive coil device (110) for use in a magnetic resonance (MR) imaging system (100), comprising a RF receive coil (114), a plug (112) for connecting the RF receive coil (114) to the MR imaging system (100), sensing means (118) for sensing the presence of a magnetic field of the MR imaging system (100), detecting means (119) for detecting if the plug (112) is connected to the MR imaging system (100), and a warning means (120, 122) for generating a warning when the sensing means (118) sense the presence of a magnetic field of the MR imaging system (100) and the detecting means (119) detect that the plug (112) is not connected to the MR imaging system (100).

Abstract: A magnetic field within a magnetic resonance (MR) imaging system (300) is measured. The MR system includes a magnet (304) with an imaging zone (308), a radio-frequency transceiver (316), and a magnetic field probe (322) located within the imaging zone. The magnetic field probe includes a fluorine sample (404) including any one of the following: a fluoroelastomer (700), a fluorine containing ionic liquid (600), and a solution of a fluorine containing compound. The field probe further includes an antenna (406) for manipulating the magnetic spins of the fluorine sample and for receiving fluorine magnetic resonance data from the fluorine sample. The antenna is connected to the radio-frequency transceiver. The method includes acquiring (100, 200) the fluorine magnetic resonance data using the magnetic resonance imaging system and calculating (102, 206) a magnetic field strength (344) using the fluorine magnetic resonance data.

Abstract: An object (10) placed in an examination volume of a MR device (1) is subject to an imaging sequence including multi-slice RF pulses for simultaneously exciting two or more spatially separate image slices. MR signals are received in parallel via a set of RF coils (11, 12, 13) having different spatial sensitivity profiles within the examination volume. An MR image is reconstructed for each image slice from the acquired MR signals. MR signal contributions from the different image slices are separated on the basis of the spatial sensitivity profiles of the RF coils (11, 12, 13). Side-band artifacts, namely MR signal contributions from regions excited by one or more side-bands of the multi-slice RF pulses, are suppressed in the reconstructed MR images on the basis of the spatial sensitivity profiles of the RF coils (11, 12, 13).

Abstract: In a method of MR imaging with an MR device (1), an object (10) is positioned in an examination volume of the MR device (1). ‘Silent’ MR imaging with T2*-weighted or diffusion-weighted contrast is enabled. The method of subjecting the object (10) to an imaging sequence comprising: includes: a) varying a magnetic field gradient vector (GX, GY, GZ) from an initial position (A) to an end position (B) over a plurality of intermediate positions while a number of RF pulses (20) is radiated in the presence of the magnetic field gradient; b) varying the magnetic field gradient vector (GX, GY, GZ) again from the initial position (A) to the end position (B) over the plurality of intermediate positions while a number of MR echo signals is acquired in the presence of the magnetic field gradient; c) sampling a spherical volume in k-space by repeating steps a) and b) a number of times for different initial, intermediate, and/or end positions; and d) reconstructing a MR image from the acquired MR echo signals.