The present disclosure provides a method for producing a radio frequency (RF) pulse for use in magnetic resonance. The steps of the method include providing a computer system and a set of RF input parameters. The computer system then generates an optimal phase surface by iteratively updating an initial RF pulse profile based at least in part on the set of RF input parameters. The optimal phase surface contains a set of iteratively generated RF pulse profiles with various characteristics, such as bandwidths or selectivity. The steps of the method further include selecting an RF pulse profile with the computer system based on a search on the optimal phase surface, which can be implemented with the help of an index file. The search can be performed using an artificial intelligence algorithm, and can retrieve the shortest pulse profile that satisfies user input parameters or requirements.

A method for correcting a B0 inhomogeneity in a magnetic resonance scan with a magnetic resonance tomograph is provided. The magnetic resonance tomograph includes a controller, a radio frequency unit, and a transmitting antenna. In the method, the controller determines a transmission signal that is suitable for correcting an effect of an inhomogeneity of a static B0 magnetic field in an examination volume by the Bloch-Siegert effect. The transmission signal is emitted into the examination volume.

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.

A protocol to determine chemical shift-specific T.sub.1 constants in inhomogeneous fields. Based on intermolecular double-quantum coherences and spatial encoding techniques, the method can resolve overlapped peaks in inhomogeneous fields using the conventional method. With inversion recovery involved, the amplitude of peaks will be modulated by the time of inversion recovery. After fitting the amplitude curves, the corresponding longitudinal relaxation time can be achieved. With the measured T.sub.1 values in inhomogeneous fields, we can have insights into the chemical exchange rates, signal optimization and data quantitation.

Aspects of the disclosure relate to systems and methods for obtaining and interpreting magnetic resonance spectroscopy (MRS) data obtained from the pancreas of a subject. In some embodiments, systems and methods of the disclosure relate to analyzing MRS spectra of metabolites, for example y-Aminobutyric acid (GABA), to assess pancreatic islet density and function in a subject. In some embodiments, systems and methods described by the disclosure are useful for the diagnosis and/or treatment of diseases associated with impaired pancreatic function, for example diabetes.

This invention provides a NMR multi-dimensional method for measuring coupling constants within several coupling networks. At first, a 90 hard pulse was performed to flip the magnetization from the Z axis to the XY plane. After t.sub.1/2, a selective 180 pulse is implemented with a simultaneous Z-direction gradient, thus reversing different protons at different slices. Then the PSYCHE element is implemented. After another t.sub.1/2, the gradient G.sub.1 and G.sub.p are implemented. At last, the EPSI readout is used to simultaneously record both the chemical-shift and the spatial information. As a result, from different specific slices, we can extract the scalar couplings between the proton reversed at this slice and other protons. These couplings lead to splittings in the indirect dimension, from which relevant coupling constants can be measured.

A method for detection and quantification of individual analytes in liquid analyte mixtures, by means of NMR spectrometry, in which method a sample of the analyte mixture has a high-frequency pulse applied to it in an NMR spectrometer, and the resulting NMR spectrum is evaluated, is to be developed further in such a manner that it allows a precise analysis of liquid analyte mixtures even when using low-field NMR spectrometers. For this purpose, the sample of the analyte mixture is placed into a low-field NMR spectrometer, and at least one high-frequency pulse that excites only one specific analyte is applied to it.

Techniques for crushing unwanted coherence pathways during magnetic resonance spectral (MRS) measurements include receiving first data that indicates a sequence of RF pulses with one or more target coherence pathways of spin states for a subject that has at least N1 coupled spin states of interest. A negative, non-integer amplitude is determined for at least one intervening crusher pulse emitted from at least one spatial gradient magnetic coil. The at least one intervening crusher pulse has a duration less than a time between successive pulses of the sequence of RF pulses; and, the intervening crusher pulse de-phases unwanted coherence pathways. A MRS device is operated using the intervening crusher pulse and the sequence of RF pulses.

A system and method of acquiring an image at a magnetic resonance imaging (MRI) system is provided. Accordingly, an analog signal based on a pulse sequence and a first gain is obtained. The analog signal is converted into a digitized signal. A potential quantization error is detected in the digitized signal based on a boundary. When the detection is affirmative, a replacement analog signal based on the pulse sequence is received. At least one portion of the replacement analog signal can be based on an adjusted gain. The adjusted gain is a factor of the first gain. The replacement analog signal is digitized into a replacement digitized signal. At least one portion of the replacement digitized signal corresponding to the at least one portion of the replacement analog signal is adjusted based on a reversal of the factor.

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.