A method for generating 2-refocusing pulses for magnetic resonance spectroscopy (MRS), and for performing spectral editing of MRS data using differential custom bandpass editing. Acquisition may be performed using echo-planar spectroscopic imaging (EPSI), for example. The 2-refocusing is achieved using chemical-shift-selective adiabatic 2-refocusing pulses, without spatial-selective (e.g. slice-selective) refocusing. The spectral editing method uses two data sets with different bandpass (full and partial) editing spectra, and takes the difference of the two edited spectra. The approach lends itself to 3D spectroscopy at B.sub.0 of 7 T or higher, and permits whole brain J-coupled metabolite editing (e.g. 2HG or GABA), with greatly reduced specific absorption rate, shorter repetition time, minimal chemical-shift displacement artefacts (CDSAs), robustness to B.sub.0-inhomogeneity and indifference to B.sub.1.sup.+-inhomogeneity compared with existing spatial-selective methods, such as MEGA.

An article includes a cylinder of single crystal sapphire for use during solid state nuclear magnetic resonance (SSNMR) measurements. The axis of the cylinder is aligned with an axis of symmetry of the single crystal. The cylinder is configured to rotate at a known angle and known fraction of an angular velocity as the sample during operation of the SSNMR system. In some uses, a current angle of a stator is determined based on separation of peaks in a measured signal from aluminum atoms in the sapphire crystal. Stator orientation is adjusted until the current angle is within a desired tolerance of a target angle, including one different from a magic angle.

In a general aspect, a magnetic resonance system performs a magnetic resonance measurement. In some examples, a magnetic resonance system includes data processing apparatus and a superheterodyne spectrometer system. The data processing apparatus generates digital intermediate frequency (IF) signal information based on a pulse profile. The digital IF signal information is configured to suppress an image sideband in a magnetic resonance control signal. The superheterodyne spectrometer generates the magnetic resonance control signal based on the digital IF signal information.

Methods, systems, and apparatus for magnetic resonance imaging (MRI) using an adiabatic magnetic pulse train are disclosed. In some aspects, a method for magnetic resonance imaging includes: applying at a first time, to a subject located in a magnetic field, a first adiabatic magnetic pulse train comprising excitation pulses and adiabatic refocusing pairs; obtaining a first MRI image comprising first MRI data acquired after the applying of the first adiabatic magnetic pulse train to the subject at the first time; applying a second adiabatic magnetic pulse train comprising excitation pulses and adiabatic refocusing pairs to the subject at a second time while the subject is located in the magnetic field; obtaining a second MRI image comprising second MRI data acquired after the applying of the second adiabatic magnetic pulse train to the subject at the second time; acquiring third MRI data corresponding to blood flow in the subject based on differences between the first MRI image and the second MRI image; and obtaining an MRI perfusion image based on the third MRI data that excludes some or all MRI artifacts arising from regions of inhomogeneity in the magnetic field.

Radio frequency (RF) gradient based magnetic resonance imaging (MRI) is provided by establishing a gradient in the RF transmit (B1) field using frequency-modulated RF pulses. A difference between the time-bandwidth product of the frequency-modulated RF pulses can be varied to provide impart different phases to magnetic resonance signals, where these different phases provide phase encoding of the acquired data. The time-bandwidth product difference can be created and varied by changing the pulse duration of one frequency-modulated RF pulse relative to the other while keeping the bandwidth of the pulses constant.