Diffusion sensitizing gradient pulse pairs are prescribed in a manner to mitigate effects of concomitant gradient artifacts. Measured MR signals generated by applying a plurality of diffusion sensitizing gradient matrices are obtained and processed to determine a second order mean diffusion tensor and a fourth order covariance tensor. Quantities derived from these tensors are measured and mapped within an imaging volume which describe features of diffusion anisotropy and heterogeneity within each imaging voxel.

An MRI apparatus according to an embodiment includes a whole body RF coil accommodated in a gantry. The whole body RF coil includes a first element unit used for transmission of a radio frequency magnetic field; and a second element unit used for reception of a magnetic resonance signal produced from a subject having been applied with the radio frequency magnetic field. The first element unit is a birdcage-type RF coil having two end rings and a plurality of rungs spaced apart from each other along the circumferential direction of the end rings. The second element unit is a microstrip antenna.

A defect centre-based sensor is disclosed. The sensor comprises instrumentation which includes a generator for causing excitation in an active element, for example a diamond, and a detector for measuring a transition in the active element. The generator is an optical source and/or the detector is an optical detector. The sensor further comprises an optical waveguide and a sensor head in communication with the source and/or the detector via the optical waveguide. The sensor head houses the active element having at least one defect centre, for example, a nitrogen vacancy, responsive to an applied magnetic field, electric field or temperature and a signal delivery arrangement, for example at least one lens, arranged to optically couple the optical waveguide to the active element.

A defect centre-based sensor is disclosed. The sensor comprises instrumentation which includes a generator for causing excitation in an active element, for example a diamond, and a detector for measuring a transition in the active element. The generator is an optical source and/or the detector is an optical detector. The sensor further comprises an optical waveguide and a sensor head in communication with the source and/or the detector via the optical waveguide. The sensor head houses the active element having at least one defect centre, for example, a nitrogen vacancy, responsive to an applied magnetic field, electric field or temperature and a signal delivery arrangement, for example at least one lens, arranged to optically couple the optical waveguide to the active element.

A magnetometer includes: a substrate; a diamond layer on the substrate, in which the diamond layer includes a defect sub-layer including multiple lattice point defects; a microwave field transmitter; an optical source configured to emit light including a first wavelength that excites the multiple lattice point defects from a ground state to an excited state; a photodetector arranged to detect photoluminescence including a second wavelength emitted from the defect sub-layer, in which the first wavelength is different from the second wavelength; and a magnet arranged adjacent to the defect sub-layer.

In a method for control, input magnetic field map data is received. In this case, the input magnetic field map data for at least one magnetic field type in each case describes a magnetic field map for a state that an examination object is in at an initial location in the MR apparatus. In this case, the estimated magnetic field map data for at least one magnetic field type in each case describes at least one magnetic field map for in each case a state that the examination object is in at an alternative location that is different compared to the initial location. Control data is determined by the system control unit, using the estimated magnetic field map data or using the input magnetic field map data and the estimated magnetic field map data. The control data is suitable for controlling the MR apparatus.

In a method for control, input magnetic field map data is received. In this case, the input magnetic field map data for at least one magnetic field type in each case describes a magnetic field map for a state that an examination object is in at an initial location in the MR apparatus. In this case, the estimated magnetic field map data for at least one magnetic field type in each case describes at least one magnetic field map for in each case a state that the examination object is in at an alternative location that is different compared to the initial location. Control data is determined by the system control unit, using the estimated magnetic field map data or using the input magnetic field map data and the estimated magnetic field map data. The control data is suitable for controlling the MR apparatus.

The invention provides for a medical imaging system (100, 300). The medical imaging system comprises a processor (104). Execution of machine executable instructions (120) causes the processor to: receive (200) magnetic resonance imaging data (122) comprising a Z-spectrum acquisition (124) for a set of saturation frequency offsets (126) and at least one reference saturation frequency offset (128); reconstruct (202) saturation frequency offset complex image data (130); reconstruct (204) a B0 map (132), a water image (134), and a fat image (136) according to a Dixon-type magnetic resonance imaging protocol; calculate (206) a water phase angle (138) using the water image and/or the fat image; calculate (208) rotated complex image data (140) by rotating the phase of the saturation frequency offset complex image data such that the complex water signal is aligned with a real axis for each voxel; perform (210) a B0 correction by calculating shifted complex image data (142); calculate (212) a frequency dependent phase angle (144) descriptive of a phase angle between the complex water signal and the complex fat signal for each of the set of saturation frequency offsets using a fat signal model comprising at least two fat species; calculate (214) a residual fat component correction factor (150) by projecting the complex fat signal onto the real axis for each of the set of saturation frequency offsets; and calculate (216) corrected water Z-spectrum image data (152) by subtracting the residual fat component correction factor for each of the set of saturation frequency offsets from the real component of the shifted complex image data.

A method for magnetic resonance imaging uses an electromagnet [304], which may have open geometry, to generate a spatially nonuniform magnetic field within an imaging region [306]. The current through the electromagnet is controlled to repeatedly cycle the nonuniform magnetic field between a high strength for polarizing spins and a low strength for spatial encoding and readout. Using RF coils [308], excitation pulses are generated at a frequency that selects a non-planar isofield slice for imaging. The RF coils are also used to generate refocusing pulses for imaging and to generate spatial encoding pulses, which may be nonlinear. Magnetic resonance signals originating from the selected non-planar isofield slice of the nonuniform magnetic field in the imaging region [306] are detected using the RF coils [308] in parallel receive mode. MRI images are reconstructed from the parallel received magnetic resonance signals, e.g., using algebraic reconstruction.

A method for magnetic resonance imaging uses an electromagnet [304], which may have open geometry, to generate a spatially nonuniform magnetic field within an imaging region [306]. The current through the electromagnet is controlled to repeatedly cycle the nonuniform magnetic field between a high strength for polarizing spins and a low strength for spatial encoding and readout. Using RF coils [308], excitation pulses are generated at a frequency that selects a non-planar isofield slice for imaging. The RF coils are also used to generate refocusing pulses for imaging and to generate spatial encoding pulses, which may be nonlinear. Magnetic resonance signals originating from the selected non-planar isofield slice of the nonuniform magnetic field in the imaging region [306] are detected using the RF coils [308] in parallel receive mode. MRI images are reconstructed from the parallel received magnetic resonance signals, e.g., using algebraic reconstruction.