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.

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.

The present disclosure addresses the challenges of in vivo phosphorus imaging by providing a clinically useful phosphorus MRI (PMRI) system and method that may be performed on a standard MRI system in a clinically reasonable scan time using specifically tuned coils, a phosphorus pulse sequence, and improved reconstruction and post processing algorithms.

It is an integrative platform for visualization, preprocessing and quantitation of MRS data acquired using single voxel, multi voxel magnetic resonance spectroscopy imaging (MRSI) and MEshcher-GArwood Point-RESolved Spectroscopy (MEGA-PRESS) acquisition methods. The method integrates both time- and frequency-domain signal processing methods on a single platform. The method is optimized for proton (.sup.1H) and phosphorous (.sup.31P) MRS data. It employs the use of iterative baseline estimation and fitting procedure to provide improved quantitation accuracy. The method can be used in both interactive and automatic mode to cater to the needs of researchers and clinicians.

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.

In a first aspect, the present invention relates to a Nuclear Magnetic Resonance (NMR) probe and method of use of a NMR probe for matching a resonant mode in a circuit to a required impedance (e.g., Z=50 Ohm) using a variable inductor which allows matching of the resonant mode in the circuit within a broad frequency range. In an additional aspect, the NMR probe and the method of use of a NMR probe allows matching of a resonant mode in a circuit to a required impedance (e.g., Z=50 Ohm) using a variable inductor without requiring the coupling constant K to be varied over a broad frequency range. In a further aspect, the invention relates to a method to detect a Nuclear NMR mode of a nuclei including the steps of introducing a sample into a NMR probe comprising a primary circuit and a secondary circuit, where the primary circuit comprises a sample coil, a first variable capacitor and a RF pulse generator, where the secondary circuit comprises a coupling loop, a variable inductor and an impedance port, introducing the NMR probe into a magnetic field, exciting the sample with the RF pulse generator, inductively coupling the coupling loop to the sample coil, adjusting the first variable capacitor and the variable inductor to match the impedance to the required impedance of the impedance port and detecting a NMR mode of a nuclei of the sample.

A system for performing magnetic resonance imaging (MRI) of a subject has a pulse sequence system that generates a pulse sequence and has a gradient system, a plurality of gradient coils, a radio-frequency system, and a plurality of RF coils. The pulse sequence system causes the subject to emit MR signals which are captured as k-space data. The system also has a k-space ordering processor that collects first k-space data and second k-space data, an MR signal modeler that generates a signal variation model, and a compensation module that applies the signal variation model to the second k-space data collected to produce compensated k-space data. A display processor reconstructs the compensated k-space data into an image of the subject. The compensated data accounts for variation in magnetization during the pulse sequence and k-space data collection to reduce artifacts in the images.

Systems and methods for magnetic resonance imaging (MRI) of multiple different nuclear spin species using the same radio frequency (RF) coil are described. Generally, multiple different nuclear spin species are imaged using the same RF coil by using an MRI system whose magnetic field can be rapidly ramped between a number of different, and arbitrary, magnetic field strengths. The magnetic field of this MRI system can be ramped to different values in reasonable amounts of time (e.g., in a time frame that is feasible within an imaging study).

Techniques are disclosed for recording magnetic resonance data with a magnetic resonance facility, wherein a three-dimensional echo-planar imaging sequence is used whereby following a single excitation period (e.g. module) in an echo train, an echo count of k-space rows is read out in a read-out direction in the k-space, and interchanging takes place between these rows by means of gradient pulses of the two phase encoding directions.

Systems and methods for magnetic resonance imaging (MRI) of multiple different nuclear spin species using the same radio frequency (RF) coil are described. Generally, multiple different nuclear spin species are imaged using the same RF coil by using an MRI system whose magnetic field can be rapidly ramped between a number of different, and arbitrary, magnetic field strengths. The magnetic field of this MRI system can be ramped to different values in reasonable amounts of time (e.g., in a time frame that is feasible within an imaging study).