Abstract: The invention relates to a method of MR imaging of a body (10) of a patient. It is an object of the invention to provide a method that reduces contrast blurring in PROPELLER imaging combined with multi-echo acquisitions.

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: 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: The invention relates to a magnetic resonance imaging system (100). The magnetic resonance imaging system (100) comprises a gradient system and a processor (124) for controlling the magnetic resonance imaging system (100). Execution of machine executable instructions causes the magnetic resonance imaging system (100) to: acquire by coil elements (114) first magnetic resonance data simultaneously from a group of passive local probes 5 (302, 312, 402, 702, 901), wherein the first group of passive local probes (302, 312, 402, 702, 901) comprises a plurality of passive local probes (302, 312, 402, 702, 901) located spaced apart from each other; disentangle contributions to the first magnetic resonance data from the individual local probes, calculate for the magnetic resonance imaging system (100) a gradient impulse response function of the gradient system using the first magnetic resonance data 10 from the local probes; determine correction factors using the gradient impulse response function.

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.

Abstract: The invention provides for a magnetic resonance imaging system (200, 300, 400) comprising a radio-frequency system (216, 214) comprising multiple coil elements (214) for acquiring magnetic resonance data (264). The magnetic resonance imaging system further comprises 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. The magnetic resonance imaging system further comprises a processor (244) for controlling the magnetic resonance imaging system.

Abstract: In an EPI acquisition sequence for magnetic resonance signals k-space is scanned along sets of lines in k-space along opposite propagation directions, e.g. odd and even lines in k-space. Phase errors that occur due to the opposite propagation directions are corrected for in a SENSE-type parallel imaging reconstruction. The phase error distribution in image space may be initially estimated, calculated form the phase difference between images reconstructed from magnetic resonance signals acquired from the respective sets of k-space lines, or from an earlier dynamic.

Abstract: An object (10) in an examination volume of a MR device (1) is imaged with improved susceptibility weighted contrast. The imaging includes the steps of: a) generating at least two echo signals at different echo times by subjecting the object (10) to an imaging sequence of RF pulses and switched magnetic field gradients; b) acquiring the echo signals; c) repeating steps a) and b) for a plurality of phase encoding steps; d) reconstructing an intermediate MR image for each echo time from the acquired echo signals; and e) generating a susceptibility weighted MR image by computing, for each voxel of the susceptibility weighted MR image, a non-linear combination of the voxel values of the intermediate MR images at the respective image position. The non-linear combination emphasizes lower voxel magnitude values more than higher voxel magnitude values.

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 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: 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 ‘silent’ MR imaging with T2-weighted or diffusion-weighted contrast.

Abstract: The invention relates to a method of MR imaging of an object positioned in an examination volume of a MR device (1), the method comprises the steps of:—subjecting the object (10) to an imaging sequence of RF pulses (20) and switched magnetic field gradients(G), which imaging sequence is a zero echo time sequence comprising: i) setting a readout magnetic field gradient (G) having a readout direction and a readout strength; ii) radiating a RF pulse (20) in the presence of the readout magnetic field gradient (G); iii) acquiring a FID signal in the presence of the readout magnetic field gradient (G), wherein the FID signal represents a radial k-space sample; iv) gradually varying the readout direction; v) sampling a spherical volume in k-space by repeating steps i) through iv) a number of times, with the readout strength being varied between repetitions;—reconstructing a MR image from the acquired FID signals, wherein signal contributions of two or more chemical species to the acquired FID signals are separated.

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 invention relates to a method of MR imaging of an object (10) placed in an examination volume of a MR device (1). The method comprises the steps of: subjecting the object (10) to an imaging sequence for acquiring MR signal data, wherein the MR signal data are acquired as a function of k-space position and time by using an irregular k-space sampling pattern with sub-sampling of k-space; reconstructing MR image data from the MR signal data, which MR image data comprise spatial dimensions and a frequency dimension, sparsity of the MR image data in a transform domain being exploited for suppressing sub-sampling artefacts in the MR image data. Moreover, the invention relates to a MR device (1) and to a computer program.

Abstract: The invention relates to a method of MR imaging of an object (10) placed in an examination volume of a MR device (1). The method comprises the steps of: subjecting the object (10) to an imaging sequence comprising multi-slice RF pulses for simultaneously exciting two or more spatially separate image slices, acquiring MR signals, wherein the MR signals are received in parallel via a set of RF coils (11, 12, 13) having different spatial sensitivity profiles within the examination volume, and reconstructing a MR image for each image slice from the acquired MR signals, wherein 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), and wherein side-band artefacts, 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: A magnetic resonance imaging system (1) includes a denoising unit (24), and a reconstruction unit (20). The denoising unit (24) denoises a partial image and provides a spatially localized measure of a denoising effectivity. The reconstruction unit (20) iteratively reconstructs an output image from the received MR data processed with a Fast Fourier Transform (FFT), and in subsequent iterations includes the denoised partial image and the spatially localized measure of the denoising effectivity.

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).