Patent classifications
G01R33/482
Systems and methods for magnetic resonance imaging
A method for magnetic resonance imaging (MRI) may include cause, based on a pulse sequence, a magnetic resonance (MR) scanner to perform a scan on an object. The pulse sequence may include a steady-state sequence and an acquisition sequence that is different from the steady-state sequence. The steady-state sequence may correspond to a steady-state phase of the scan in which no MR data is acquired. The acquisition sequence may correspond to an acquisition phase of the scan in which MR data of the object is acquired. The method may also include generating one or more images of the object based on the MR data.
RATIOMETRIC PULSED CEST IMAGING
The present invention relates to on the use of exogenous agents having a pool of mobile proton(s) in CEST-MR imaging to generate Chemical Exchange Rotation Transfer-based CEST contrast, and to a ratiometric-based CEST-MR procedure that comprises using these exogenous agents to set-up CERT-based concentration-independent CEST MR imaging, and as responsive agents to set-up CERT-based concentration independent responsiveness.
Method and device for controlling a magnetic resonance imaging system
Techniques are described for controlling a magnetic resonance imaging system to facilitate an improvement in Simultaneous Multislice Imaging, especially concerning a compensation of eddy currents. This is achieved by simultaneously measuring at least two slices by the magnetic resonance imaging system while applying a pulse sequence. In the course of the pulse sequence for measuring k-space lines, a set of in-plane encoding signals (that are typically gradients) are applied with a set of Hadamard encoding signals in an interleaved scheme.
System and method for magnetic resonance fingerprinting with non-locally sequential sampling of k-space
A system and method is provided for acquisition of magnetic resonance fingerprinting (“MRF”) data that includes determining a non-locally sequential sampling pattern for a Cartesian grid of k-space, performing a series of sequence blocks using acquisition parameters that vary between sequence blocks to acquire MRF data from a subject using the Cartesian grid of k-space and the determined non-locally sequential sampling pattern, assembling the MRF data into a series of signal evolutions, comparing the series of signal evolutions to a dictionary of known signal evolutions to determine tissue properties of the subject, and generating a report indicating the tissue properties of the subject.
Magnetic resonance imaging method and system with optimal variable flip angles
A method and system for improving the quality of MR images acquired with optimal variable flip angles includes receiving MRI parameters for a target tissue, selecting at least one objective function from a plurality of objective functions, simulating a relationship between each flip angle and the at least one objective functions based on the MRI parameters, determining optimal variable flip angle distribution to reach optimization of the at least one objective function for whole acquisition of the MR image, selecting or optimizing a k-space strategy, applying a plurality of radio frequency (RF) pulses with the optimal variable flip angle distribution and the k-space strategy to a target area in an object, receiving MR signals from the target area, the MR signals corresponding to the plurality of RF pulses, acquiring, in the k-space strategy, k-space lines based on the MR signals, and reconstructing the MR image from the k-space lines.
Echo sharing in imaging sequences with multiple delays and multiple spin echoes
Techniques are described for generating an MR image of an object using a multi spin-echo based imaging sequence with a plurality of k space segments using a preparation pulse. The technique included acquiring a first k-space dataset of the object using a first echo time and a first delay after the preparation pulse before the several spin-echoes are acquired. The technique further includes acquiring a second k space dataset of the object using a second echo time and a second delay after the preparation pulse, with at least one of the second echo time and the second delay time being different from the corresponding first echo time and the first delay time, generating a combined k space, and generating the MR image based on the combined k space dataset.
METHOD FOR GENERATING AT LEAST ONE IMAGE DATASET AND ONE REFERENCE IMAGE DATASET, DATA CARRIER, COMPUTER PROGRAM PRODUCT, AND MAGNETIC RESONANCE SYSTEM
In a method for generating an image dataset and one reference image dataset: a first raw dataset is provided that is recorded using a MR system, the first raw dataset including measurement signals at readout points in k-space that lie on a first k-space trajectory; a second raw dataset is provided that is recorded using the same MR system and on the same examination object, the second raw dataset including measurement signals at readout points in k-space that lie on a second, different k-space trajectory; image datasets are reconstructed from the first raw dataset, where a separate equalization coefficient set is used before the reconstruction of each image dataset; a reference image dataset is reconstructed from the second raw dataset; the reference image data set is compared with each image dataset to generate respective similarity values; and the image dataset is selected with a greatest similarity value.
METHOD FOR GENERATING AT LEAST ONE IMAGE DATA SET AND ONE REFERENCE IMAGE DATA SET, DATA CARRIER, COMPUTER PROGRAM PRODUCT AND MAGNETIC RESONANCE SYSTEM
In a method for generating an image data set and a reference image data set: a first raw data set is provided that is acquired with a MR system and that includes measurement signals at read-out points in k-space that lie on a first k-space trajectory; a second raw data set is provided that is acquired with the same MR system and at the same examination object at read-out points that lie on a second, different k-space trajectory that is different from the first k-space trajectory; image data sets are reconstructed from the first raw data set; a reference image data set is reconstructed from the second raw data set; the reference image data set is compared with each image dataset to generate respective similarity values; and an image data set is selected having a greatest similarity value.
Method for varying undersampling dimension for accelerating multiple-acquisition magnetic resonance imaging and device for the same
Provided is an MRI image generation method including: acquiring first phase encoding lines obtained by undersampling along a first direction using an MRI device; acquiring second phase encoding lines obtained by undersampling in a second direction different from the first direction using the MRI device; generating a first MRI image based on the first phase encoding lines and the second phase encoding lines; and generating a second MRI image different from the first MRI image based on the first phase encoding lines and the second phase encoding lines.
Method for echo planar time-resolved magnetic resonance imaging
Systems and methods for magnetic resonance imaging (“MRI”) that address the geometric distortions and blurring common to conventional echo planar imaging (“EPI”) sequences, and that provide new temporal signal evolution information across the EPI readout, are described. Echo planar time-resolved imaging (“EPTI”) schemes are described to implement an accelerated sampling of a hybrid space spanned by the phase encoding dimension and the temporal dimension. In general, each EPTI shot covers a segment of this hybrid space using a zigzag trajectory with an interleaved acceleration in the phase-encoding direction. The hybrid space may be undersampled and a tilted reconstruction kernel used to synthesize additional data samples.