Described here are systems and methods for volumetric excitation in magnetic resonance imaging (MRI) using frequency modulated radio frequency (RF) pulses. In general, quadratic phase modulation along the slice encoding direction is implemented for additional spatiotemporal encoding, which better distributes signal content in the slice direction and enables higher acceleration rates that are robust to slice-undersampling.

Described are methods and apparatus, referred to as temperature-lock, which can control and stabilize the sample temperature in an NMR spectrometer, in some instances with a precision and an accuracy of below about 0.1 K. In conventional setups, sample heating caused by experiments with high-power radio frequency pulses is not readily detected and is corrected by a cumbersome manual procedure. In contrast, the temperature-lock disclosed herein automatically maintains the sample at the same reference temperature over the course of different NMR experiments. The temperature-lock can work by continuous or non-continuous measurement of the resonance frequency of a suitable temperature-lock nucleus and simultaneous adaptation of a temperature control signal to stabilize the sample at a reference temperature value. Inter-scan periods with variable length can be used to maintain the sample at thermal equilibrium over the full length of an experiment.

A transmission signal generator generates a lock transmission signal that excites a lock nucleus (deuteron) used for observing a change of a static magnetic field. A LOCK transmission circuit transmits the lock transmission signal to an NMR probe. A LOCK reception circuit receives an NMR signal of the lock nucleus. A LOCK transmission sequencer, based on a pulse sequence generated according to at least one of amplitude modulation, frequency modulation, or phase modulation, controls generation of the lock transmission signal performed by the transmission signal generator.

Methods of fingerprinting a specific molecule in a composition using nuclear magnetic resonance (NMR) is disclosed. The disclosed NMR methods provide several modifications and improvements over existing NMR techniques. In some embodiments, the methods include applying a cycle of signal processing steps, including applying a radio frequency (RF) pulse, applying a gradient pulse having a pulse length less than or equal to 1000 ?s, and applying a water suppression technique (WET). In some embodiments, the methods further include repeating the cycle for at least 3 times to acquire an enhanced signal of the composition. In some embodiments, the methods further include fingerprinting the specific molecule based on the enhanced signal of the composition.

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.

Embodiments can provide a method for multi-banded RF-pulse enhanced magnetization imaging, the method comprising determining, by a processor, a frequency offset against a central frequency by specifying an offset frequency for one or more RF coils close to a frequency peak of mobile water; and simultaneously applying, by one or more RF coils, one or more bands of Gaussian RF pulses around the central frequency to a patient from a medical imaging device; wherein the one or more bands of Gaussian RF pulses are symmetrically applied having a distance from the central frequency equal to the frequency offset.

Magnetic resonance imaging (MRI) acquisition and reconstruction techniques that invert MR signals of selected frequencies without the application of inversion RF pulses are disclosed. An example method comprises acquisition of at least one MR image representative dataset and an associated phase reference dataset, and classifies anatomical material into a first component representing anatomical material having a first range of resonance frequencies associated with a first range of phase differences between the MR image representative dataset and the reference image dataset and a second component representing anatomical material having a second range of resonance frequencies associated with a second range of phase differences between the MR image representative dataset and the reference image dataset. The method assigns different visual attributes to first and second components derived using phase differences between the MR image representative dataset and the reference image dataset and displays an image.

An MR Spectroscopy (MRS) system and approach is provided for diagnosing painful and non-painful discs in chronic, severe low back pain patients (DDD-MRS). A DDD-MRS pulse sequence generates and acquires DDD-MRS spectra within intervertebral disc nuclei for later signal processing & diagnostic analysis. An interfacing DDD-MRS signal processor receives output signals of the DDD-MRS spectra acquired and is configured to optimize signal-to-noise ratio (SNR) by an automated system that selectively conducts optimal channel selection, phase and frequency correction, and frame editing as appropriate for a given acquisition series. A diagnostic processor calculates a diagnostic value for the disc based upon a weighted factor set of criteria that uses MRS data extracted from the acquired and processed MRS spectra along regions associated with multiple chemicals that have been correlated to painful vs. non-painful discs. A diagnostic display provides a scaled, color coded legend and indication of results for each disc analyzed as an overlay onto a mid-sagittal T2-weighted MRI image of the lumbar spine for the patient being diagnosed. Clinical application of the embodiments provides a non-invasive, objective, pain-free, reliable approach for diagnosing painful vs. non-painful discs by simply extending and enhancing the utility of otherwise standard MRI exams of the lumbar spine.

A pH-weighted chemical exchange saturation transfer (CEST) magnetic resonance imaging (MRI) method and system are provided that works by indirectly measuring the NMR signal from amine protons found on the backbones of amino acids and other metabolites, which resonate at a frequency of +2.8-3.2 ppm with respect to bulk water protons. The technique uses a modified magnetization transfer radiofrequency saturation pulse for the generation of image contrast. A train of three 100 ms Gaussian pulses at high amplitude (6 uT) or Sinc3 pulses are played at a particular frequency off-resonance from bulk water prior to a fast echo planar imaging (EPI) readout, with one full image acquired at each offset frequency. This non-invasive pH-weighted MRI technique does not require exogenous contrast agents and can be used in preclinical investigations and clinical monitoring in patients with malignant glioma, stroke, and other ailments.

A whole measurement process includes a plurality of step combinations. Each of the step combinations is composed of a solution-state measurement step and a solid-state measurement step. In the solution-state measurement step, solution-state NMR measurement is performed such that magnetization that is to be used in the solid-state measurement step remains. In the solid-state measurement step, solid-state NMR measurement is performed by using the magnetization that remains. No waiting time for recovering magnetization is provided between the solution-state measurement step and the solid-state measurement step. The solid-state measurement step may be performed earlier, and the solution-state measurement step may be performed later. Alternatively, the two steps may be performed simultaneously.