Abstract: The invention relates to a method of MR imaging of an object (10). It is an object of the invention to enable MR imaging using a 3D radial or spiral acquisition scheme providing an enhanced image quality in the presence of motion. The method comprises the steps of: —generating MR signals by subjecting the object (10) to an imaging sequence comprising RF pulses and switched magnetic field gradients; —acquiring the MR signals using a 3D radial or spiral acquisition scheme with oversampling of a central portion (26) of k-space; —detecting motion-induced displacements (d) and/or deformations of the object (10) during the acquisition of the MR signals and assigning each of the acquired MR signals to a motion state; —reconstructing an MR image from the MR signals weighted in the central portion (26) of k-space, wherein a stronger weighting (W, 30) is applied to MR signals acquired in more frequent motion states, while a weaker weighting (W, 31, 32) is applied to MR signals acquired in less frequent motion states.

Abstract: Disclosed herein is a medical system (100, 300) comprising a memory (110) storing machine executable instructions (120) and an image segmentation algorithm (122). The image segmentation algorithm is configured for outputting one or more prede-termined anatomical regions within initial magnetic resonance imaging data (124) descriptive of a predetermined field of view (109) of a subject (318).

Abstract: The invention relates to a method of MR imaging of an object (10) placed in an examination volume of an MR apparatus (1). It is an object of the invention to enable fast 3D MR imaging that provides motion-compensation and also allows a precise compensation for system imperfections. The method of the invention comprises the steps of: —subjecting the object (10) to a number of shots (S1-S4) of a 3D imaging sequence, wherein a train of MR signals is generated by each shot (S1-S4), each MR signal representing a k-space profile, wherein the set of k-space profiles of each shot (S1-S4) comprises at least one navigator profile and a number of imaging profiles; —acquiring the MR signals; —deriving motion information from the at least one navigator profile; and —reconstructing an MR image from the imaging profiles, wherein a motion-compensation is applied based on the motion information.

Abstract: The invention relates to a method of MR imaging of an object (10). It is an object of the invention to enable MR imaging using a 3D radial or spiral acquisition scheme providing an enhanced image quality in the presence of motion. The method comprises the steps of: —generating MR signals by subjecting the object (10) to an imaging sequence comprising RF pulses and switched magnetic field gradients; —acquiring the MR signals using a 3D radial or spiral acquisition scheme with oversampling of a central portion (26) of k-space; —detecting motion-induced displacements (d) and/or deformations of the object (10) during the acquisition of the MR signals and assigning each of the acquired MR signals to a motion state; —reconstructing an MR image from the MR signals weighted in the central portion (26) of k-space, wherein a stronger weighting (W, 30) is applied to MR signals acquired in more frequent motion states, while a weaker weighting (W, 31, 32) is applied to MR signals acquired in less frequent motion states.

Abstract: A magnetic resonance (MR) imaging technique enables parallel imaging in combination with fat suppression at an increased image quality, notably in combination with EPI. The method includes acquiring reference MR signal data from the object in a pre-scan and acquiring imaging MR signal data from the object in parallel via one or more receiving coils having different spatial sensitivity profiles. The MR signal data are acquired with sub-sampling of k-space and with spectral fat suppression and an MR image is reconstructed from the imaging MR signal data. Sub-sampling artefacts are eliminated using sensitivity maps indicating the spatial sensitivity profiles of the two or more RF receiving coils. A B0 map is derived from the reference MR signal data and the spatial dependence of the effectivity of the spectral fat suppression is determined using the Bo map.

Abstract: The invention relates to a method of magnetic resonance (MR) imaging of an object positioned in an examination volume of a MR device. One aspect of the invention provides a method that enables parallel imaging in combination with fat suppression at an increased image quality, notably in combination with EPI. The method includes: acquiring reference MR signal data from the object in a pre-scan, acquiring imaging MR signal data from the object in parallel via one or more receiving coils having different spatial sensitivity profiles, wherein the MR signal data are acquired with sub-sampling of k-space and with spectral fat suppression, and reconstructing an MR image from the imaging MR signal data, wherein sub-sampling artefacts are eliminated using sensitivity maps indicating the spatial sensitivity profiles of the two or more RF receiving coils. A B0 map is derived from the reference MR signal data and the spatial dependence of the effectivity of the spectral fat suppression is determined using the B0 map.

Abstract: A method of MR imaging includes acquiring reference MR signal data from the object (10); deriving a B0 map from the reference MR signal data; adapting sensitivity maps according to the B0 map, which sensitivity maps indicate spatial sensitivity profiles of one or more RF receiving coils (11, 12, 13), to correct for geometric distortions of the sensitivity maps; acquiring imaging MR signal data from the object (10) via the one or more receiving coils (11, 12, 13) with sub-sampling of k-space; and reconstructing a MR image from the imaging MR signal data. Sub-sampling artifacts are eliminated using the adapted sensitivity maps. The reference MR signal data are acquired using a multi-point Dixon technique. A water image and a fat image are reconstructed from the imaging MR signal data using separate water and fat sensitivity maps. The water and fat images are preferably reconstructed using regularized SENSE.

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 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: acquiring reference MR signal data from the object (10); deriving a Bo map from the reference MR signal data; adapting sensitivity maps according to the B0 map, which sensitivity maps indicate spatial sensitivity profiles of one or more RF receiving coils (11, 12, 13), to correct for geometric distortions of the sensitivity maps; acquiring imaging MR signal data from the object (10) via the one or more receiving coils (11, 12, 13) with sub-sampling of k-space; and reconstructing a MR image from the imaging MR signal data, wherein sub-sampling artefacts are eliminated using the adapted sensitivity maps. In a preferred embodiment, the reference MR signal data are acquired using a multi-point Dixon technique, wherein a water map and a fat map are derived from the reference MR signal data.

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 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 an MR device (1). The object of the invention is to provide an improved, i.e. faster, parallel imaging technique. The invention proposes to acquire a survey signal data set (21, 22) at a low image resolution, which survey signal data set (21, 22) includes MR signals received in parallel or successively via a volume RF coil (9) and via a set of array RF coils (11, 12, 13). Spatial sensitivity profiles (23) of the array RF coils (11, 12, 13) are determined from the low resolution data. As a next step, a reference scan is performed in which a reference signal data set (25) is acquired at intermediate resolution solely via the array RF coils (11, 12, 13). The spatial sensitivity profiles (27) of the array RF coils (11, 12, 13) are determined from the data acquired at intermediate resolution and from the spatial sensitivity profiles (23) determined before at low resolution.

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 an MR device (1). The object of the invention is to provide an improved, i.e. faster, parallel imaging technique. The invention proposes to acquire a survey signal data set (21, 22) at a low image resolution, which survey signal data set (21, 22) includes MR signals received in parallel or successively via a volume RF coil (9) and via a set of array RF coils (11, 12, 13). Spatial sensitivity profiles (23) of the array RF coils (11, 12, 13) are determined from the low resolution data. As a next step, a reference scan is performed in which a reference signal data set (25) is acquired at intermediate resolution solely via the array RF coils (11, 12, 13). The spatial sensitivity profiles (27) of the array RF coils (11, 12, 13) are determined from the data acquired at intermediate resolution and from the spatial sensitivity profiles (23) determined before at low resolution.