Embodiments of a compact portable nuclear magnetic resonance (NMR) device are described which generally include a housing that provides a magnetic shield; an axisymmetric permanent magnet assembly in the housing and having a bore, a plurality of magnetic elements that together provide a well confined axisymmetric magnetization for generating a near-homogenous magnetic dipole field B.sub.0 directed along a longitudinal axis and providing a sample cavity for receiving a sample, and high magnetic permeability soft steel poles to improve field uniformity: a shimming assembly with coils disposed at the longitudinal axis for spatially correcting the near homogenous magnetic field B.sub.0; and a spectrometer having a control unit for measuring a metabolite in the sample by applying magnetic stimulus pulses to the sample, measuring free induction delay signals generated by an ensemble of hydrogen protons within the sample; and suppressing a water signal by using a dephasing gradient with frequency selective suppression.

A technology is provided for multi-component and/or multi-configuration imaging with coding, signal composition, signal model, structure model, structure model learning, decoding, reconstruction, performance prediction and performance enhancement. A magnetic resonance imaging example comprises acquiring signal samples in accordance with a coding scheme and a k-space sampling scheme, identifying a structure model in a data assembly formed using an extraction operation, and generating a result consistent with both the acquired signal samples and the identified structure model.

A method for performing magnetic resonance imaging is provided. The method includes providing a magnetic resonance imaging system comprising: a radio frequency receive system comprising a radio frequency receive coil, and a housing, wherein the housing comprises a permanent magnet for providing an inhomogeneous permanent gradient field, a radio frequency transmit system, and a single-sided gradient coil set. The method also includes placing the receive coil proximate a target subject; applying a sequence of chirped pulses via the transmit system; applying a multi-slice excitation along the inhomogeneous permanent gradient field; applying a plurality of gradient pulses via the gradient coil set orthogonal to the inhomogeneous permanent gradient field; acquiring a signal of the target subject via the receive system, wherein the signal comprises at least two chirped pulses; and forming a magnetic resonance image of the target subject.

A method for acquiring nuclear magnetic resonance (NMR) phase-sensitive two-dimensional (2D) J-resolved spectrum by suppressing strong coupling spurious peaks, comprising: 1) placing a sample, collecting a conventional one-dimensional (1D) spectrum of the sample, and measuring a time width (pw) of a 90° pulse, wherein the conventional 1D spectrum provides J coupling information and chemical shift information of the sample; and 2) introducing a pulse sequence for suppressing strong coupling, setting parameters of a chirp sweep frequency pulse, a pure shift yielded by chirp excitation (PSYCHE) module, and a J sampling module, and collecting and saving data of a spectrum.

In a Method and a device for magnetic resonance imaging of a subject using a spoiled gradient echo sequence, a B.sub.0 magnetic field strength of at most 1.5 T is used during the sequence. As part of the sequence a slice select gradient acting as a spoil gradient is played out. Substantially simultaneously with the slice select gradient a predetermined RF pulse is played out in the sequence, wherein a time-bandwidth product of the RF pulse is set so that a majority of the energy of the RF pulse is transmitted in its central main lobe.

A method for acquiring nuclear magnetic resonance (NMR) phase-sensitive two-dimensional (2D) J-resolved spectrum by suppressing strong coupling spurious peaks, comprising: 1) placing a sample, collecting a conventional one-dimensional (1D) spectrum of the sample, and measuring a time width (pw) of a 90° pulse, wherein the conventional 1D spectrum provides J coupling information and chemical shift information of the sample; and 2) introducing a pulse sequence for suppressing strong coupling, setting parameters of a chirp sweep frequency pulse, a pure shift yielded by chirp excitation (PSYCHE) module, and a J sampling module, and collecting and saving data of a spectrum.

A method for performing magnetic resonance imaging is provided. The method includes providing a magnetic resonance imaging system comprising: a radio frequency receive system comprising a radio frequency receive coil, and a housing, wherein the housing comprises a permanent magnet for providing an inhomogeneous permanent gradient field, a radio frequency transmit system, and a single-sided gradient coil set. The method also includes placing the receive coil proximate a target subject; applying a sequence of chirped pulses via the transmit system; applying a multi-slice excitation along the inhomogeneous permanent gradient field; applying a plurality of gradient pulses via the gradient coil set orthogonal to the inhomogeneous permanent gradient field; acquiring a signal of the target subject via the receive system, wherein the signal comprises at least two chirped pulses; and forming a magnetic resonance image of the target subject.

The present document describes methods and systems for exciting magnetic resonance in a sample using trains of pulsed, oscillating magnetic fields that are modulated in their phase and amplitude according to a source waveform derived from the known or estimated magnetic response of a sample. Also disclosed are methods and systems for acquiring a response signal from the sample wherein data acquisition events are synchronized or interleaved with said modulated pulse trains. Further disclosed are methods and systems for identifying one or more of the presence, absence, amount, and concentration of a target substance in a sample. Also disclosed is a magnetic resonance device which uses such pulse trains and synchronized acquisition to improve the selectivity of magnetic resonance data.

Methods and systems for Nuclear Magnetic Resonance (NMR) spectra of complex chemical mixtures are described. The methods and systems allow undesired NMR spectral background to be removed or suppressed and target spectral peaks to be uncovered, for example, when strong background signals overlap weaker peaks. In some embodiments, the methods and systems employ a quantum filter utilizing nuclear spin singlet states.

A plurality of stimulations is transmitted to tissue or other material using one or more transmitters. The plurality of signals associated with the excited tissue and the transmitted stimulations are measured. The measured signals are processed to generate field-related quantities, such as B1+ and/or MR signal maps. Field-related quantities are generated also from simulation, by calculating the one or more incident fields from a simulator model of the one or more transmitters and assuming a given distribution of electrical properties in the tissue or other material. Field-related quantities generated from simulation and experimental procedures are compared to each other. The assumed electrical properties distribution is updated and the procedure is repeated iteratively until the difference between simulated and experimental field-related quantities is smaller than a threshold.