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: —generating MR signals by subjecting the object to an imaging sequence, —acquiring MR signal profiles in a Cartesian k-space sampling scheme, wherein each MR signal profile is acquired in the presence of a temporally constant magnetic field gradient along a readout direction and a sinusoidally modulated magnetic field gradient along a phase encoding direction, and—reconstructing an MR image from the acquired MR signal profiles taking the modulation scheme of the magnetic field gradients into account. The invention proposes that the frequency of the sinusoidal modulation of the magnetic field gradient is varied during acquisition of each MR signal profile. Moreover, the invention relates to a MR device for carrying out this method as well as to a computer program to be run on a MR device.

Abstract: The invention provides for a medical imaging system (700) comprising: a memory (734) for storing machine executable instructions (740), a display (732) for rendering a user interface (800), and a processor (730). Execution of the machine executable instructions causes the processor to receive (1000) three dimensional medical image data (746) descriptive of a region of interest (709) of a subject (718). The region of interest comprises a spine (200). Execution of the machine executable instructions further causes the processor to receive (1002) a set of spinal coordinate systems (748) each descriptive of a location and an orientation of spinal vertebrae in the three dimensional medical image data. The set of spinal coordinate systems further comprises a set of spine centerline positions (102) each positioned on a spine centerline (108).

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: —generating MR signals by subjecting the object to an imaging sequence, —acquiring MR signal profiles in a Cartesian k-space sampling scheme, wherein each MR signal profile is acquired in the presence of a temporally constant magnetic field gradient along a readout direction and a sinusoidally modulated magnetic field gradient along a phase encoding direction, and —reconstructing an MR image from the acquired MR signal profiles taking the modulation scheme of the magnetic field gradients into account. The invention proposes that the frequency of the sinusoidal modulation of the magnetic field gradient is varied during acquisition of each MR signal profile. Moreover, the invention relates to a MR device for carrying out this method as well as to a computer program to be run on a MR device.

Abstract: The invention provides for a magnetic resonance imaging system (100) for acquiring magnetic resonance data (142) from a subject (118) within an imaging zone (108). The magnetic resonance imaging system comprises a memory (134, 136) for storing machine executable instructions (160), and pulse sequence commands (140, 400, 502, 600, 700), wherein the pulse sequence commands are configured to cause the magnetic imaging resonance system to acquire the magnetic resonance data according to a magnetic resonance fingerprinting technique. The pulse sequence commands are further configured to control the magnetic resonance imaging system to perform spatial encoding using a zero echo time magnetic resonance imaging protocol.

Abstract: The invention provides for a medical imaging system (700) comprising: a memory (734) for storing machine executable instructions (740), a display (732) for rendering a user interface (800), and a processor (730). Execution of the machine executable instructions causes the processor to receive (1000) three dimensional medical image data (746) descriptive of a region of interest (709) of a subject (718). The region of interest comprises a spine (200). Execution of the machine executable instructions further causes the processor to receive (1002) a set of spinal coordinate systems (748) each descriptive of a location and an orientation of spinal vertebrae in the three dimensional medical image data. The set of spinal coordinate systems further comprises a set of spine centerline positions (102) each positioned on a spine centerline (108).

Abstract: The invention provides for a magnetic resonance imaging system (100) for acquiring magnetic resonance data (142) from a subject (118) within an imaging zone (108). The magnetic resonance imaging system comprises a memory (134, 136) for storing machine executable instructions (160), and pulse sequence commands (140, 400, 502, 600, 700), wherein the pulse sequence commands are configured to cause the magnetic imaging resonance system to acquire the magnetic resonance data according to a magnetic resonance fingerprinting technique. The pulse sequence commands are further configured to control the magnetic resonance imaging system to perform spatial encoding using a zero echo time magnetic resonance imaging protocol.

Abstract: A medical imaging system (10) includes a nuclear imaging system (62), a timing optimization unit (40), a magnetic resonance (MR) scanner (12), an MR reconstruction unit (38), and an attenuation map unit (50). The nuclear imaging system (62) receives nuclear decay data and generates at least one nuclear image (64) of a first resolution based on the received nuclear decay data of an imaged subject (16) and an attenuation map (52). The timing optimization unit (40) which selects a first and a second echo time for a modified Dixon (mDixon) pulse sequence and a sufficient number of repetition times (TRs) to generate an image of the subject (16) of at least a first resolution, with the phase angle difference between water and fat at the first and the second echo time being unequal to 0° and 180°. The MR scanner (12) applies the sequence to the subject (16) and receives MR data (32) from the subject. The MR reconstruction unit (38) reconstructs at least one MR image (44) based on the MR data (32).

Abstract: The invention relates to a method of MR imaging of an object (10) placed in the examination volume of a MR device (1). It is the object of the invention to provide an improved MR-based temperature mapping method.

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 enables efficient compensation of flow artifacts, especially for MR angiography in combination with Dixon water/fat separation. The method of the invention comprises the steps of: a) generating MR echo signals at two or more echo times by subjecting the portion of the body (10) to a MR imaging sequence of RF pulses and switched magnetic field gradients, wherein the MR imaging sequence is a Dixon sequence; b) acquiring the MR echo signals; c) reconstructing one or more single-echo MR images from the MR echo signals; d) segmenting the blood vessels from the MR images; e) detecting and compensating for blood flow-induced variations of the amplitude or phase in the single-echo MR images within the blood vessel lumen, and f) separating signal contributions from water and fat spins to the compensated single-echo MR images.

Abstract: A magnetic resonance imaging system (200, 300) acquires magnetic resonance data (242, 244). A processor (230) controls the magnetic resonance imaging system to execute instructions (250, 252, 254, 256, 258) which cause the processor to repeatedly: control (100) the magnetic resonance imaging system to acquire magnetic resonance data including magnetic resonance 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 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 phase-modulated 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 at least two 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 at least two RF coils (11, 12, 13) and on the basis of the phase modulation scheme of the RF pulses.

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 enables efficient compensation of flow artifacts, especially for MR angiography in combination with Dixon water/fat separation. The method of the invention comprises the steps of: a) generating MR echo signals at two or more echo times by subjecting the portion of the body (10) to a MR imaging sequence of RF pulses and switched magnetic field gradients, wherein the MR imaging sequence is a Dixon sequence; b) acquiring the MR echo signals; c) reconstructing one or more single-echo MR images from the MR echo signals; d) segmenting the blood vessels from the MR images; e) detecting and compensating for blood flow-induced variations of the amplitude or phase in the single-echo MR images within the blood vessel lumen, and f) separating signal contributions from water and fat spins to the compensated single-echo MR images.

Abstract: At least two gradient echo signals are generated at two different echo times by subjecting a portion of a body (10) in an MR examination region (1) to an imaging sequence of RF pulses and switched magnetic field gradients. The 0th moment of the readout magnetic field gradient essentially vanishes at the time of a first gradient echo while the 1st moment of the readout gradient is non-zero. Both the 0th and 1st moments of the readout magnetic field gradient essentially vanish at a time of a second gradient echo. Gradient echo signals are acquired. Acquiring the gradient echo signals is repeated for a plurality of phase encoding steps. A first MR image is reconstructed from the gradient echo signals of the first gradient echo and a second MR image is reconstructed from the gradient echo signals of the second gradient echo. Ghosting artefacts in the first and/or second MR image are identified by comparing the first and second MR images.

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: 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 wherein the black blood module 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 sensitization 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 an object (10) placed in the examination volume of a MR device (1). It is the object of the invention to provide an improved MR-based temperature mapping method.

Abstract: A medical imaging system (10) includes a nuclear imaging system (62), a timing optimization unit (40), a magnetic resonance (MR) scanner (12), an MR reconstruction unit (38), and an attenuation map unit (50). The nuclear imaging system (62) receives nuclear decay data and generates at least one nuclear image (64) of a first resolution based on the received nuclear decay data of an imaged subject (16) and an attenuation map (52). The timing optimization unit (40) which selects a first and a second echo time for a modified Dixon (mDixon) pulse sequence and a sufficient number of repetition times (TRs) to generate an image of the subject (16) of at least a first resolution, with the phase angle difference between water and fat at the first and the second echo time being unequal to 0° and 180°. The MR scanner (12) applies the sequence to the subject (16) and receives MR data (32) from the subject. The MR reconstruction unit (38) reconstructs at least one MR image (44) based on the MR data (32).

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 phase-modulated 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 at least two 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 at least two RF coils (11, 12, 13) and on the basis of the phase modulation scheme of the RF pulses.

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.