A magnetic resonance member 1 includes a crystal structure and is capable of electron spin quantum operations with microwaves of different frequencies corresponding to arrangement orientations of a vacancy and an impurity in a crystal lattice. A magnetic field transmission unit 4 senses a measurement target magnetic field at plural measurement positions different from each other, and applies application magnetic fields corresponding to the measurement target magnetic field sensed at the plural measurement positions to the magnetic resonance member 1 along respective different directions corresponding to the aforementioned arrangement orientations. A measurement control unit 21 controls a high frequency power supply 12, and determines detection values detected by a detecting device (an irradiating device 5 and a light receiving device 6) of the physical phenomena corresponding to the plural measurement positions. A calculation unit 22 calculates the measurement target magnetic field at the plural measurement positions on the basis of the detection values.

A magnetic resonance member 1 includes a crystal structure and is capable of electron spin quantum operations with microwaves of different frequencies corresponding to arrangement orientations of a vacancy and an impurity in a crystal lattice. A magnetic field transmission unit 4 senses a measurement target magnetic field at plural measurement positions different from each other, and applies application magnetic fields corresponding to the measurement target magnetic field sensed at the plural measurement positions to the magnetic resonance member 1 along respective different directions corresponding to the aforementioned arrangement orientations. A measurement control unit 21 controls a high frequency power supply 12, and determines detection values detected by a detecting device (an irradiating device 5 and a light receiving device 6) of the physical phenomena corresponding to the plural measurement positions. A calculation unit 22 calculates the measurement target magnetic field at the plural measurement positions on the basis of the detection values.

A method and apparatus for determining spatial distribution of a complex radio frequency (RF) of both transmit field and receive sensitivity a magnetic resonance imaging (MRI) system. The method includes estimation of the absolute phase of transmit field using a reference transmit coil or array coils with minimal absolute phase. The method and apparatus include estimation of complex receive sensitivity of a transceiver coil using the complex transmit field of the transceiver coil or array coils.

The invention provides for a magnetic resonance imaging system (100, 300, 100) for acquiring magnetic resonance data (110, 1104) from a subject (118) within an imaging zone (108). The magnetic resonance imaging system comprises a memory (136) for storing machine executable instructions (160, 162, 164, 166, 316) and pulse sequence data (140, 1102). The pulse sequence data comprises instructions for controlling the magnetic resonance imaging system to acquire magnetic resonance data according to a magnetic resonance imaging method. The magnetic resonance imaging system further comprises a processor (130) for controlling the magnetic resonance imaging system. Execution of the machine executable instructions causes the processor to: acquire (1200) the magnetic resonance data by controlling the magnetic resonance imaging system with the pulse sequence data; calculate (1202) a B0 inhomogeneity map (148) by analyzing the magnetic resonance data according to the magnetic resonance imaging method, calculate (1204) a B1 phase map (150) and/or a B1 amplitude map (1106) by analyzing the magnetic resonance data according to the magnetic resonance imaging method; and calculate (1206) a second derivative (1110) of the B1 phase map and/or a second derivative of the B1 magnitude map 1 and/or a second derivative of the B0 in homogeneity map in at least one predetermined direction. The second derivative is calculated using a corrected voxel size in the at least one predetermined direction, wherein the corrected voxel size is calculated using a correction factor calculated from the derivative of the B0 inhomogeneity map.

A hysteresis effect-based Field Free Point-Magnetic Particle Imaging (FFP-MPI) method includes the following steps: acquiring a hysteresis loop model of Superparamagnetic Iron Oxide Nanoparticles (SPIOs); calculating to obtain a Point Spread Function (PSF) of the SPIOs on the basis of a sinusoidal excitation magnetic field and the hysteresis loop model of the SPIOs; acquiring an original reconstructed image of FFP-MPI on the basis an FFP moving track and a voltage signal; performing deconvolution on the original image with respect to the PSF considering an hysteresis effect, so as to obtain a final reconstructed image; the artifacts and phase errors of image reconstruction caused by the hysteresis effect of the SPIOs with large particle sizes are reduced, the deficiency in reconstruction by the traditional reconstruction method that ignores the hysteresis effect is overcome, the reconstruction speed and the resolution are greatly improved, and the application range of the SPIOs is expanded.

An image processing apparatus according to an embodiment includes processing circuitry. The processing circuitry is configured to obtain two magnetic resonance images corresponding to two phase encoding directions opposite to each other. The processing circuitry is configured to generate a shift map related to shifting a plurality of pixels in the two magnetic resonance images, by optimizing a cost function using a first difference between the two magnetic resonance images and a second difference between two edge images generated on the basis of the two magnetic resonance images. The processing circuitry is configured to generate a correction image obtained by correcting distortions of the two magnetic resonance images on the basis of the two magnetic resonance images and the shift map.

Methods, systems, and apparatus for signal artifact detection and reduction are provided. The signal artifact may comprise an interference between an electroencephalography (EEG) signal and a magnetic resonance imaging (MRI) signal arising out of simultaneous EEG and MRI treatment.

Methods, systems, and apparatus for signal artifact detection and reduction are provided. The signal artifact may comprise an interference between an electroencephalography (EEG) signal and a magnetic resonance imaging (MRI) signal arising out of simultaneous EEG and MRI treatment.

Systems and methods for designing and fabricating three-dimensional objects with precisely computed material compositions for use in enhancing electromagnetic fields for magnetic resonance imaging (“MRI”) are provided. As examples, the fabricated object can be designed to reduce magnetic field inhomogeneities in the main magnetic field of an MRI system, or to reduce inhomogeneities in a transmit radio frequency (“RF”) field (i.e., a B.sub.1 field). As examples, the object can be a shim; a housing or other part of an RF coil; a medical device, such as a surgical implant; or component used in a medical device, such as a housing for an implantable medical device.

In a magnetic field source detecting apparatus, a magnetic sensor unit detects an intensity and a direction of a measurement target magnetic field on or over a surface of a test target object; and a position estimating unit estimates a position in a depth direction of a magnetic field source that exists at an unspecified position inside a test target object on the basis of the intensities and the directions of the measurement target magnetic field detected by the magnetic sensor at at least two 2-dimensional positions of the surface.