G01R33/5613

Magnetic resonance imaging apparatus

In one embodiment, a magnetic resonance imaging apparatus includes memory circuitry configured to store a predetermined program; and processing circuitry configured, by executing the predetermined program, to set an FSE type pulse sequence in which an excitation pulse is followed by a plurality of refocusing pulses, the plurality of the refocusing being divided into at least a first pulse group subsequent to the excitation pulse and a second pulse group subsequent to the first pulse group, the first pulse group including refocusing pulses having a predetermined high flip angle, and the second pulse group including refocusing pulses having flip angles decreased from the predetermined high flip angle toward a flip angle of zero, and generate an image of an object from respective MR signals corresponding to the plurality of refocusing pulses acquired by applying the fast spin echo type pulse sequence to the object.

Method, neural network, and magnetic resonance apparatus for assigning magnetic resonance fingerprints

In a method for determining magnetic resonance (MR) parameters, an MR fingerprint of a voxel is acquired by execution of a pulse sequence, the MR fingerprint is provided as an input into the input layer of a trained neural network, and at least one MR parameter relating to the MR fingerprint is provided at the output layer of the neural network.

Quantitative prostate cancer imaging with magnetic resonance fingerprinting (MRF)

Example embodiments associated with characterizing a sample using NMR fingerprinting are described. One example NMR apparatus includes an NMR logic that repetitively and variably samples a (k, t, E) space associated with an object to acquire a set of NMR signals that are associated with different points in the (k, t, E) space. Sampling is performed with t and/or E varying in a non-constant way. The NMR apparatus may also include a signal logic that produces an NMR signal evolution from the NMR signals and a characterization logic that characterizes a tissue in the object as a result of comparing acquired signals to reference signals. Example embodiments facilitate distinguishing prostate cancer tissue from normal peripheral zone tissue based on quantitative data acquired using NMR fingerprinting in combination with apparent diffusion co-efficient (ADC) values or perfusion values acquired using DWI-MRI or DCE-MRI.

Method and magnetic resonance apparatus for acquiring diagnostic measurement data of a heart

In a method and magnetic resonance apparatus for recording diagnostic measurement data of a heart of an examination object, the magnetic resonance apparatus is operated by a control sequence wherein an RF pulse excites nuclear spins with a flip angle of at least 60, the diagnostic measurement data are recorded in a coordinate system independent of the heart, and the basic magnetic field produced by the magnetic resonance apparatus is smaller than 1.0 tesla.

Free-breathing 3D body diffusion imaging using motion-compensated diffusion preparation and motion robust readout

Embodiments can provide a computer-implemented method for free breathing three dimensional diffusion imaging, the method comprising initiating, via a k-space component processor, diffusion/T2 preparation, comprising generating diffusion contrast; and adjusting one or more of amplitude, duration, and polarity to set a first order moment; applying, via an image data processor, a stack of stars k-space ordering, comprising acquiring a radial/spiral view for all members of a plurality of partitions in a partition-encoding direction; increasing an azimuthal angle until a complete set of radial/spiral views are sampled; and applying diffusion gradients along each of three axis simultaneously; and calculating, via the image data processor, an apparent diffusion coefficient map.

MAGNETIC RESONANCE IMAGING

The present invention relates generally to medical imaging and, more particularly, relates to systems and methods for obtaining magnetic resonance (MR) images of tissues and organs (particularly of the heart) or parts thereof.

MAGNETIC RESONANCE IMAGING USING ADDITIONAL GRADIENT PULSES
20200132795 · 2020-04-30 · ·

Method for MR imaging of an acquisition region during a patient examination. In order to determine a point spread function, in a prior measurement for each of additional gradient output directions, the method includes choosing, in the acquisition region, a slice lying outside of an isocenter of the MR device, which slice extends in a plane perpendicular to the additional gradient output direction under consideration; following a respective slice-selective excitation of the selected slice, acquiring first calibration data using the additional gradient pulse of the additional gradient output direction under consideration, and acquiring second calibration data omitting the additional gradient pulse in each case along a k-space line, wherein a same timing sequence of additional gradient pulse and readout time window is used as in the MR sequence; and calculating, from the first and second calibration data, the point spread function for the additional gradient output direction under consideration.

Method and magnetic resonance apparatus for generating a fat fraction-corrected T1 parameter map

In a magnetic resonance (MR) apparatus and a method for operating such an apparatus, a T1 parameter map is generated with fat fraction correction, by using a model in which the fat fraction of acquired MR data is used as a known parameter. The T1 values from the acquired MR data are fat fraction-corrected in such a manner, so as to generate fat fraction-corrected entries for the T1 parameter map according to the model.

MULTI-STATE MAGNETIC RESONANCE FINGERPRINTING

The invention provides for a magnetic resonance imaging system (100) for acquiring magnetic resonance data (142) from a subject (118) within a measurement zone (108). The magnetic resonance imaging system (100) comprises: a processor (130) for controlling the magnetic resonance imaging system (100) and a memory (136) storing machine executable instructions (150, 152, 154), pulse sequence commands (140) and a dictionary (144). The pulse sequence commands (140) are configured for controlling the magnetic resonance imaging system (100) to acquire the magnetic resonance data (142) of multiple steady state free precession (SSFP) states per repetition time. The pulse sequence commands (140) are further configured for controlling the magnetic resonance imaging system (100) to acquire the magnetic resonance data (142) of the multiple steady state free precession (SSFP) states according to a magnetic resonance fingerprinting protocol. The dictionary (144) comprises a plurality of tissue parameter sets. Each tissue parameter set is assigned with signal evolution data pre-calculated for multiple SSFP states.

PROPELLER MR IMAGING

The invention relates to a method of MR imaging of a body (10) of a patient. It is an object of the invention to provide a method that reduces contrast blurring in PROPELLER imaging combined with multi-echo acquisitions. The method of the invention comprises the steps of: generating MR signals by subjecting at least a portion of the body (10) to a MR imaging sequence comprising a number of RF pulses and switched magnetic field gradients; acquiring the MR signals as a plurality of k-space blades (21-26) in temporal succession according to a PROPELLER scheme, each k-space blade (21-26) comprising a number of substantially parallel k-space lines, wherein the k-space blades (21-26) are rotated about the center of k-space, so that the total acquired data set of MR signals spans at least part of a circle in k-space, wherein a common central circular region of k-space is covered by all k-space blades (21-26), wherein a relaxation weighting of the MR signals varies between different k-space blades (21-26); estimating the relaxation weighting of the MR signals; compensating the acquired MR signals according to the estimated relaxation weighting; andreconstructing a MR image from the compensated MR signals. Moreover, the invention relates to a MR device (1) and to a computer program for a MR device (1).