In a magnetic resonance method and apparatus for time-of-flight vascular imaging, a magnetic field is applied to an imaging volume and an inflow volume, from which liquid enters into the imaging volume, of an examination person. The imaging volume is excited by an RF pulse, which fulfills a magnetization transfer function and a fat saturation function, while the magnetic field is being applied. The RF pulse has a frequency distribution whose frequencies are higher than the center frequency of water in the imaging volume, and that includes the fat frequency in the imaging volume. The magnetic field has a field distribution with an apex with essentially no spatial gradient in the imaging volume and having a higher spatial gradient in the inflow volume, so that the center frequency of water in the inflow volume is shifted in the direction of lower frequencies and is no longer affected by the RF pulse.

A method for the preparation of a sample comprising highly polarized nuclear spins is proposed, comprising at least the following steps: a) provision of molecules with 1,2-dione structural units and/or molecules with 2,5-diene-1,4-dione structural units in the solid state; b) generation of radicals from these molecules by photo induced electron transfer by a first electromagnetic irradiation in the visible or ultraviolet frequency range in the solid state; c) dynamic nuclear polarization in the presence of a magnetic field in the solid state by applying a second electromagnetic irradiation with a frequency adapted to transfer spin polarization from the electrons to the nuclear spins leading to a highly polarized state thereof. Furthermore uses of correspondingly prepared samples for NMR, MRS and MRI experiments are proposed.

A method of operating a magnetic resonance imaging (MRI) apparatus includes exciting a body coil of the MRI apparatus to emit a radio-frequency signal, determining a center frequency of a resonance curve of the body coil, and calculating a magnet target frequency based on the determined center frequency. A magnet is ramped to the magnet target frequency.

An MRI apparatus according to an embodiment includes sequence controlling circuitry, in a first transition period, repeating application of a first MT pulse and acquisition of a first MR signal to a first frequency region being a part of a k-space; in the first steady state, repeating application of the first MT pulse and acquisition of a second MR signal to a second frequency region of the k-space, frequency in second frequency region being lower than frequency in the first frequency region; and in a second transition period, repeating application of a second MT pulse and acquisition of a third MR signal to a third frequency region being another part of the k-space, frequency in the third frequency region being higher than the frequency in the second frequency region, and processing circuitry generating one MR image on basis of the first, second, and third MR signal.

Polarizable diamond materials and methods for obtaining nuclear magnetic resonance spectra of samples external to the diamond materials are described. The diamond materials can include .sup.12C, .sup.13C, substitutional nitrogen, and nitrogen vacancy defects in a crystalline lattice, wherein the substitutional nitrogen concentration is between 10 ppm and 200 ppm, the nitrogen vacancy concentration is between 10 ppb and 10 ppm, and the .sup.13C concentration is greater than 1.1% and not more than 25%. Methods for obtaining nuclear magnetic resonance spectra can include optically pumping a diamond material to generate electron spin hyperpolarization in nitrogen vacancy centers, transferring the electron spin hyperpolarization to nuclei of the sample, and generating a nuclear magnetic resonance spectrum by applying a magnetic field to the sample, exciting the sample with a radio frequency pulse, and detecting a nuclear magnetic resonance response from the sample.

Magnetic resonance imaging (MRI) systems and methods using adiabatic tip-down and matched adiabatic flip-back pulses are disclosed. According to an aspect, a system includes a signal generator configured to generate a pulse sequence for on-resonance magnetization transfer preparation. The pulse sequence includes an adiabatic tip-down pulse and a matched adiabatic flip-back pulse for separating spins in a mobile spin pool from spins in a bound spin pool of an anatomical region of interest for imaging. The system includes radio frequency (RF) coils configured to transmit RF pulses in response to the pulse sequence and to acquire RF data in response to transmission of the RF pulses. Further, the system includes a processing system configured to process the RF data to provide a display image indicating different tissue types with discrimination.

A magnetic resonance imaging (MRI) system and method integrating multi-nuclide synchronous imaging and spectral imaging is provided. The MRI system includes a spectral imaging module, a multi-nuclide synchronous imaging module, and a spectral reconstruction and image fusion module, where the spectral imaging module is configured to acquire a spectrum of a nuclide Nuc; the multi-nuclide synchronous imaging module is configured to perform synchronous imaging of nuclides Nuc1 . . . Nucn, where when n=1, Nucl is .sup.1H; and when n>1, Nucn is a non-.sup.1H nuclide; and the spectral reconstruction and image fusion module is configured to receive the spectrum of the nuclide Nuc and images of the nuclides Nuc1 . . . Nucn, and acquire spatial distribution information of compounds of the nuclide Nuc and spatial distribution information of the non-.sup.1H nuclide through fusion. The system and method can synchronously acquire MR signals of different nuclides, and reconstruct and fuse non-.sup.1H nuclide images.

MRI techniques provide robust imaging in the presence of inhomogeneity in the B1 (RF) and/or B0 magnetic fields. The techniques include using a magnetization prep sequence that includes an adiabatic half passage (AHP) followed by a spin-lock pulse, followed by a reverse AHP, after which a data acquisition sequence can be applied. The AHP and reverse AHP can have amplitude and frequency modulated to sweep through a region of frequency space. The RF amplitude of the AHP and reverse AHP can be designed to be equal to the spin-lock amplitude. Quantification of a magnetization relaxation parameter (e.g., T1rho) can use a modified relaxation model that accounts for relaxation effects during the reverse AHP. A dual-acquisition technique in which the reverse AHP of the second magnetization prep sequence has opposite frequency modulation to the reverse AHP of the first magnetization prep sequence can also be used.

A method according to the invention for the slice-specific adjustment of RF pulses when recording MR signals of an examination subject with the use of a slice multiplexing method in which MR signals from at least two different slices of the examination subject are detected simultaneously when recording the MR signals, has the following steps. The respective position of the slices to be simultaneously detected in the examination subject are determined and designated in a processor. For each slice to be detected simultaneously, monoslice RF pulse parameters are determined in the processor based on the determined position of the respective slice. The monoslice RF pulse parameters are corrected in the processor based on at least one examination subject-specific parameter map, which maps the spatial distribution of a system parameter in the examination subject, and the determined position. A multiband RF pulse is determined in the processor, for manipulation of the slices to be detected simultaneously based on the corrected monoslice RF pulse parameters. An electronic signal is emitted by the processor that represents the RF pulse, in a form useable to operate the MR scanner in the acquisition of the MR signals.

A high-quality image is obtained using a two-dimensional selective excitation method even if the static magnetic field is not uniform. Therefore, non-uniformity of a static magnetic field of a region to be focused in particular in a selective excitation region excited by 2DRF is measured, and a result of the measurement is reflected in an imaging sequence using the 2DRF. For example, a resonance frequency of magnetization obtained from the measurement result is set as an irradiation frequency of the 2DRF. In addition, a shim gradient magnetic field is applied so as to correct the non-uniformity of the magnetization obtained from the measurement result. These are applied only in the imaging sequence using the 2DRF, and an irradiation frequency and a shim gradient magnetic field set in a conventional method are used in other imaging sequences.