G01R33/5616

Optimised pulse sequences for evaluating spatial frequency content of a selectively excited internal volume

In a structural analysis using NMR techniques, a method for gathering k-value data from frequency encoded spin echoes generated from internal volumes selectively excited by intersecting 90° and 180° slice selective and refocusing RF pulses and subjected to a read gradient for the purpose of quantifying the spatial frequency content of the selected internal volume without contamination by a FID signal, comprising: acquiring spin echo data such that the FID signal generated by imperfections in the 180° slice selective refocusing RF pulse is attenuated by the read gradient such that any remaining FID signal is spatially encoded with higher k-values than the frequency encoded k-values being recorded for subsequent structural analysis while simultaneously providing for t2 t2* and t1 contrast. Other aspects of the invention are disclosed.

Magnetic resonance imaging apparatus and magnetic resonance imaging method

According to one embodiment, an MRI apparatus includes a data acquiring unit and processing circuitry. The data acquiring unit acquires MR signals for imaging according to data acquiring conditions for acquiring MR signals multiple times following one excitation. The data acquiring unit also acquires reference MR signals for phase correction of real space data for imaging. The real space data are generated based on the MR signals for imaging. The processing circuitry is configured to calculate a phase error, in a real space region, of reference real space data and generate MR image data based on the MR signals for imaging with the phase correction of the real space data for imaging based on the calculated phase error. The reference real space data are generated based on the reference MR signals. The real space region is determined based on conditions of acquiring the reference MR signals or the like.

Optimization of the noise development of a 3D gradient echo sequence in a magnetic resonance system

In a method according to optimize the noise development of a 3D gradient echo sequence in a magnetic resonance system, an optimization of at least one parameter of the gradient echo sequence, from the group including: the excitation pulse (the duration of the excitation pulse); the order of k-space lines to be scanned in k-space; and the readout direction of the k-space lines to be scanned in k-space, is implemented such that the gradients to be switched have optimally minimal slew rates, amplitudes and/or polarity changes.

Method and apparatus for acquiring a magnetic resonance image data set and magnetic resonance device

In a method and apparatus for acquiring a magnetic resonance image data set of a scan area of an examination subject, the image data are acquired with a magnetic resonance apparatus having a transmitter coil that emits a radio-frequency signal having at least two transmission channels so that different polarizations of the radio-frequency signal are produced, and a magnetic resonance sequence is used to acquire raw data for the magnetic resonance image data set, wherein raw data are acquired during at least two scanning operations with the magnetic resonance sequence, with different polarizations of the radio-frequency signals being used for at least two of the at least two scanning operations, following which the magnetic resonance image data set is determined by averaging the raw data.

Multislice acquisition with incoherent aliasing

A method for producing images of a subject with a MRI system is provided. A radio frequency (RF) excitation field in combination with a slice-select magnetic gradient field along a slice-select direction is provided. At least one readout magnetic field gradient is established along a frequency-encoding direction and at least one phase encoding magnetic field gradient along a phase-encoding direction. The RF field or magnetic field gradient is manipulated along a slice-select direction in order to impart a sequence of phase shifts to the formed echo signals such that image data corresponding to an at least one adjacent slice location is incoherently aliased across a field-of-view (FOV) of a current slice location. Image data is acquired indicative of the formed echo signals. A plurality of images of the subject is reconstructed.

Method for recording a magnetic resonance image data set, data carrier, computer-program product, and magnetic resonance system
11681002 · 2023-06-20 · ·

A method for recording a magnetic resonance image data set includes providing a magnetic resonance sequence. The magnetic resonance sequence includes at least one radio-frequency pulse and a slice-selection gradient pulse applied during or before the radio-frequency pulse, which is configured as non-constant. The method includes providing at least one correction term for compensating a magnetic field change of the slice-selection gradient pulse. The magnetic field change is ascertained via a transfer characteristic of the gradient system of the magnetic resonance system. The method also includes recording at least one magnetic resonance image data set with the magnetic resonance sequence using the correction term.

Chemical Shift Correction for Multi-Point Magnetic Resonance Measurements
20230184858 · 2023-06-15 · ·

In an optimization to obtain spin-species specific magnetic resonance images, the optimization may use a target function that calculates a dephasing of a second spin species with respect to the first spin species based on a sampling trajectory of a respective measurement protocol.

System and method for modeling brain dynamics in normal and diseased states

A system and method is provided for modeling brain dynamics in normal and diseased states.

System and method for multi-modality quantification of neuroinflammation in central nervous system diseases

Methods and systems for diagnosing a condition of a central nervous system are provided. A method includes providing a DBSI-MRI data set obtained from the central nervous system of the subject, and transforming the DBSI-MRI data set to obtain at least one DBSI biomarker value. The method further includes comparing each DBSI biomarker value to at least one corresponding threshold value from a diagnostic database to obtain a relation between each DBSI biomarker value and the at least one corresponding threshold value, and diagnosing the condition according to at least one diagnostic rule, wherein each diagnostic rule defines a candidate condition in terms of the relations between the at least one DBSI biomarker value and the at least one corresponding threshold value.

Diffusion MR imaging with fat suppression

A fat suppressed diffusion image determination apparatus, a corresponding method and a corresponding computer program determine a diffusion weighted magnetic resonance image (DWI) of an object. The fat suppressed diffusion image determination apparatus includes a diffusion reference image providing unit for providing a diffusion reference MR image of the object, a fat image determination unit for determining a fat image from the diffusion reference MR image, a diffusion weighted image providing unit for providing a diffusion weighted MR image of the object, a fat suppressed image determination unit for determining a fat suppressed diffusion weighted MR image using a combination of the diffusion weighted MR image and the fat image.