Abstract: The invention provides for a magnetic resonance imaging system (200, 300) for acquiring magnetic resonance data (242, 244). A processor (230) for controlling the magnetic resonance imaging system executes instructions (250, 252, 254, 256, 258) which cause the processor to repeatedly: control (100) the magnetic resonance imaging system to acquire a portion of the magnetic resonance data, wherein each portion of the magnetic resonance data comprises navigator data (244); create (102) a set of navigator vectors by extracting the navigator data from each portion of the magnetic resonance data; construct (104) a dissimilarity matrix (246, 400, 700, 800, 900, 1000, 1100, 1400, 1500) by calculating a metric between each of the set of navigator vectors; generate (106) a matrix classification (248) of the dissimilarity matrix using a classification algorithm; and control (108) the magnetic resonance imaging system to modify acquisition of the magnetic resonance data using the matrix classification.

Abstract: The invention relates to a method of MR imaging of a body (10) placed in the examination volume of a MR device (1). It is an object of the invention to provide a method that enables efficient compensation of flow artefacts, especially for contrast-enhanced MR angiography in combination with Dixon water/fat separation.

Abstract: A black blood magnetic resonance imaging sequence is performed using a magnetic resonance scanner. The sequence includes: applying a first flow sensitization gradient; applying a spoiler gradient after applying the first flow sensitization gradient; applying a second flow sensitization gradient after applying the spoiler gradient wherein the second flow sensitization gradient has area equal to the first flow sensitization gradient but of opposite polarity; applying a slice-selective radio frequency excitation pulse after applying the spoiler gradient; and performing a magnetic resonance readout after applying the second flow sensitization gradient and after applying the slice selective radio frequency excitation. The readout acquires magnetic resonance imaging data having blood signal suppression in the region excited by the slice-selective radio frequency excitation pulse. The magnetic resonance imaging data is suitably reconstructed to generate a black blood image that may be displayed.

Abstract: Interleaved black/bright imaging (IBBI) is performed using a magnetic resonance (MR) scanner (10) wherein the black blood module (52) of the IBBI includes: applying a first flow sensitization gradient; applying a spoiler gradient after applying the first flow sensitization gradient; applying a second flow sensitization gradient after applying the spoiler gradient wherein the second flow sensitization gradient has area equal to the first flow sensitation gradient but of opposite polarity; applying a slice selective radio frequency excitation pulse after applying the spoiler gradient; and performing a MR readout after applying the second flow sensitization gradient and after applying the slice selective radio frequency excitation wherein the readout acquires MR imaging data having blood signal suppression in the region excited by the slice selective radio frequency excitation pulse.

Abstract: The invention relates to a method of MR imaging of at least a portion of a body (10) of a patient placed in an examination volume of a MR device (1), the method comprising the steps of: subjecting the portion of the body (10) to a first imaging sequence for acquiring a first signal data set (21); subjecting the portion of the body (10) to a second imaging sequence for acquiring a second signal data set (23), wherein the imaging parameters of the second imaging sequence differ from the imaging parameters of the first imaging sequence; reconstructing a MR image from the second signal data set (23) by means of regularization using the first signal data set (21) as prior information. Moreover, the invention relates to a MR device (1) and to a computer program for a MR device (1).

Abstract: The invention relates to a method of performing coronary magnetic resonance angiography with signal separation for water and fat, the method comprising: acquiring coronary magnetic resonance angiography datasets using multi-echo Dixon acquisition, processing (314; 316; 318) the datasets for reconstruction of a first (320) and second (322) image data set, the first and second image data set comprising separate water and fat image data, wherein the processing of the datasets comprises a Dixon reconstruction technique.

Abstract: A method for generating an MR image of an object situated in an examination volume of an MR apparatus begins with the acquisition of a plurality of echo signals having at least two different echo-time values (t1, t2, t3). The echo signals are generated from high-frequency pulses and magnetic-field gradient pulses by an imaging sequence. An intermediate MR image (5, 6, 7) is then reconstructed for each echo-time value (t1, t2, t3). By analyzing these intermediate MR images (5, 6, 7), local relaxation times (T2*(x)) and/or local frequency shifts (??(x)) are determined by taking account of the respective echo-time values (t1, t2, t3). Finally, a definitive MR image (11) is reconstructed from the echo signals (1) in their entirety.

Abstract: An MR device for MR imaging includes an RF coil system. In order to enable switching to and fro between different applications in such an MR device without having to move the patient so as to position a new RF coil system, it is proposed to provide the RF coil system for the transmission and/or reception of RF signals with at least two RF coil arrays which are integrated in one coil former and have been optimized for different applications, each RF coil array comprising at least two RF coils which are decoupled from one another.

Abstract: The invention relates to an MR method for generating an image of a body part of a patient located in the examination volume of an MR device. According to the method, firstly MR signals are excited in the examination volume by means of a sequence of magnetic field gradient pulses (15, 16, 17) and/or RF pulses (14). Thereafter, the MR signals are recorded by means of an RF coil arrangement of the MR device, where the RF coil arrangement has a number of coil elements that can be actuated individually. Finally, image reconstruction from the recorded MR signals takes place.

Abstract: The invention relates to a method for generating an MR image of an object situated in an examination volume of an MR apparatus. The method begins with the acquisition of a plurality of echo signals having at least two different echo-time values (ti, t2, t3), the echo signals being generated from high-frequency pulses and magnetic-field gradient pulses by means of an imaging sequence. An intermediate MR image (5, 6, 7) is then reconstructed for each echo-time value (ti, t2, t3). By analyzing these intermediate MR images (5, 6, 7), local relaxation times (T2*(x)) and/or local frequency shifts (Aw(x)) are determined by taking account of the respective echo-time values (t1, t2, t3). Finally, a definitive MR image (11) is reconstructed from the echo signals (1) in their entirety.

Abstract: The present invention relates to an MR device for MR imaging as well as to an RF coil system for such an MR device. In order to enable switching to and fro between different applications in such an MR device without having to move the patient so as to position a new RF coil system, it is proposed in accordance with the invention to provide the RF coil system for the transmission and/or reception of RF signals with at least two RF coil arrays which are integrated in one coil former and have been optimized for different applications, each RF coil array comprising at least two RF coils which are decoupled from one another.

Abstract: The invention relates to an MR method in which a navigator pulse is generated to excite a nuclear magnetization in a spatially limited volume by at least one RF pulse and at least two gradient magnetic fields having gradients which extend differently in respect of time and space. After the navigator pulse excitation, at least one MR signal is received from the volume in conjunction with a further gradient magnetic field for evaluation. In order to enhance the navigator pulse, a variation in time is imposed on the gradient magnetic fields in order to generate at least two MR signals which correspond to an excitation in the k space along mutually offset trajectories. The MR signals are combined.

Abstract: The invention relates to an MR method in which a navigator pulse is generated so as to excite the nuclear magnetization in a spatially limited volume by means of at least one RF pulse and at least two gradient magnetic fields having gradients which extend differently in respect of time and space, after which at least one MR signal is received from the volume in conjunction with a further gradient magnetic field, so as to be evaluated. In order to enhance the navigator pulse, such a variation in time is imposed on the gradient magnetic fields that there are generated at least two MR signals which correspond to an excitation in the k space along mutually offset trajectories, and the MR signals are combined.

Abstract: The invention relates to an MR method in which a navigator pulse is generated to excite a nuclear magnetization in a spatially limited volume by at least one RF pulse and at least two gradient magnetic fields having gradients which extend differently in respect of time and space. After the navigator pulse excitation, at least one MR signal is received from the volume in conjunction with a further gradient magnetic field for evaluation. In order to enhance the navigator pulse, a variation in time is imposed on the gradient magnetic fields in order to generate at least two MR signals which correspond to an excitation in the k space along mutually offset trajectories. The MR signals are combined.

Abstract: A magnetic resonance imaging method is proposed wherein a magnetic resonance image is reconstructed from magnetic resonance signals from respective signal channels. More specifically, individual signal channels relate to respective surface coils which are employed as receiver antennas for the magnetic resonance signals. The magnetic resonance signals are acquired with sub-sampling of the k-space. Resampling on a regular square grid is performed, thus enabling fast Fourier transformation in the reconstruction of the magnetic resonance image. Furthermore, the reconstruction is carried out on the basis of the spatial sensitivity profile of the receiver antennas, i.e. of the surface coils, so as to separate contributions from different spatial positions in the sub-sampled magnetic resonance signals. Preferably, a spiral-shaped acquisition trajectory is followed in the k-space.

Abstract: A magnetic resonance imaging method is proposed wherein a magnetic resonance image is reconstructed from magnetic resonance signals from respective signal channels. More specifically, individual signal channels relate to respective surface coils which are employed as receiver antennas for the magnetic resonance signals. The magnetic resonance signals are acquired with sub-sampling of the k-space. Resampling on a regular square grid is performed, thus enabling fast Fourier transformation in the reconstruction of the magnetic resonance image. Furthermore, the reconstruction is carried out on the basis of the spatial sensitivity profile of the receiver antennas, i.e. of the surface coils, so as to separate contributions from different spatial positions in the sub-sampled magnetic resonance signals. Preferably, a spiral-shaped acquisition trajectory is followed in the k-space.

Abstract: The invention relates to an MR method in which a navigator pulse is generated so as to excite the nuclear magnetization in a spatially limited volume by means of at least one RF pulse and at least two gradient magnetic fields having gradients which extend differently in respect of time and space, after which at least one MR signal is received from the volume in conjunction with a further gradient magnetic field, so as to be evaluated. In order to enhance the navigator pulse, such a variation in time is imposed on the gradient magnetic fields that there are generated at least two MR signals which correspond to an excitation in the k space along mutually offset trajectories, and the MR signals are combined.

Abstract: The invention relates to an MR method and an MR device for determining the position of at least one microcoil (11, 12) which is provided in or on an object (1) to be examined which is situated in an examination zone. During the acquisition of microcoil MR signals (S), at least one variable magnetic gradient field acts on the examination zone, so that the k space is scanned at scanning points (k.sub.x (t.sub.i), k.sub.y (t.sub.i)). The position (x, y) of the microcoil (11, 12) is determined from at least three scanning values (S(t.sub.i)) of a microcoil MR signal and the associated scanning points (k.sub.x (T.sub.i), k.sub.y (t.sub.i)) for example by solving a system of equations formed from these values. The MR method can be used for various scanning modes of the k space, and the acquisition of the microcoil MR signals (S) does not require any MR sequences other than the MR sequences required for determining the nuclear magnetization distribution in the examination zone.

Abstract: A method of determining the spatial and/or spectral distribution of nuclear magnetization in separate regions (which are not coherent in respect of space or frequency) utilizes multi-dimensional RF pulses which are configured such that it is possible to determine the nuclear magnetization distribution in the individual regions from a linear combination of the MR signals occurring subsequent to an excitation (or from MR data derived therefrom). This results in shorter measuring times or a more attractive signal-to-noise ratio.

Abstract: The invention relates to an MR method with reduced motion artefacts in which the displacement of a pulsating object, or of a part thereof, which is present in an examination zone is continuously measured relative to a reference position, and in which the reconstruction of an MR image utilizes exclusively MR signals acquired from the examination zone while the displacement from the reference position reaches or falls below a threshold value. This gating is enhanced in accordance with the invention in that prior to the acquisition of the MR signals there are generated phase encoding gradients k.sub.y) which act on the examination zone with different time integrals and that the threshold value (v.sub.s) can be varied in dependence on the respective phase encoding gradient (k.sub.y).