Patent classifications
G01R33/4826
Magnetic resonance imaging apparatus
In one embodiment, a magnetic resonance imaging apparatus includes: a scanner that includes a static magnetic field magnet configured to generate a static magnetic field, a gradient coil configured to generate a gradient magnetic field, and a WB (Whole Body) coil configured to apply an RF pulse to an object; and processing circuitry. The processing circuitry is configured to: set (i) a pulse sequence in which a sequence element is repeated, the sequence element including at least an inversion pulse and (ii) a data acquisition sequence executed after a delay time from the inversion pulse; and cause the scanner to execute the pulse sequence by using virtual gating.
Continuous Three-Dimensional Imaging for Magnetic Resonance Elastography
Described here are systems and methods for a robust magnetic resonance elastography (“MRE”) imaging platform for rapid dynamic 3D MRE imaging. The imaging platform includes an MRE pulse sequence and advanced image reconstruction framework that work synergistically in order to greatly expand the domains where MRE can be deployed successfully.
METHOD FOR ACQUIRING A THREE-DIMENSIONAL MAGNETIC RESONANCE IMAGE DATASET AND FOR GENERATING A MOTION-CORRECTED IMAGE DATASET
A three-dimensional magnetic resonance image dataset of an object is acquired using a multi-shot imaging protocol in which several k-space lines are acquired in one shot. The three-dimensional k-space includes a central region and a periphery, wherein the sampling order of k-space lines differs between the central region and the periphery. At least one k-space line from each shot passes through the central region, whereas the periphery includes regions, which are sampled by k-space lines from a subset of the plurality of shots.
Ascertaining a PSF for reconstructing image data from scan data recorded by means of a magnetic resonance system
Techniques are disclosed for ascertaining a point spread function (PSF) for reconstructing image data from scan data recorded by means of a magnetic resonance system. The techniques include a comparison of values determined for a planned k-space trajectory for parameters characterizing the k-space trajectory with baseline values of the parameters characterizing the k-space trajectory deposited in a database for the magnetic resonance system, in each case together with an associated point spread function PSF to ascertain baseline values of the deposited baseline values that are as similar as possible to the values determined for the planned k-space trajectory for the parameters characterizing the k-space trajectory and, on the basis of this deposited PSF, a PSF to be used for a reconstruction of final image data is ascertained.
SYSTEMS AND METHODS FOR LOW-FIELD FAST SPIN ECHO IMAGING
A magnetic resonance imaging (MRI) system and method for acquiring magnetic resonance (MR) images using a pulse sequence implementing driven equilibrium and quadratic phase cycling techniques is provided. The method includes, during a pulse repetition period of a pulse sequence and using a quadratic phase cycling scheme, applying a first RF pulse to deflect a net magnetization vector associated with the subject from a longitudinal plane into a transverse plane; after applying the first RF pulse, applying a first sequence of RF pulses each of which flips the net magnetization vector by approximately 180 degrees within the transverse plane; and after applying the first sequence of RF pulses, applying a second RF pulse to deflect the net magnetization vector from the transverse plane to the longitudinal plane.
MR Imaging Method and Apparatus and Computer-Readable Storage Medium
An MR imaging method and apparatus and a computer-readable storage medium. The method includes: collecting MR signal data every set time interval according to a stack-of-stars scheme or stack-of-spirals scheme, where in each time interval, MR signal data of each of a plurality of parallel slices arranged along a slice direction is collected as a k-space slice, and the k-space slices of the plurality of parallel slices are stacked into a k-space column along the slice direction; in a process of collecting the MR signal data, performing motion detection by utilizing a pilot tone signal, and marking MR signal data collected during a body motion as motion damage data when the body motion is detected; and performing motion correction on MR signal data after the motion damage data for k-space columns successively collected in a plurality of time intervals, and obtaining a current MR image based on MR signal data obtained after the motion correction and MR signal data before the motion damage data.
Method for recording measurement data using a magnetic resonance system with a correction of k-space trajectories
In a method for recording measurement data, frequency-dependent parameters characterizing a gradient unit are loaded, a k-space trajectory planned for a MR measurement and having at least one frequency component is loaded, MR measurement data is acquired based on the planned k-space trajectory and reconstructing image data from the MR measurement data, wherein the planned k-space trajectory is corrected based on the at least one frequency component of the planned k-space trajectory and the frequency-dependent parameters, and an electronic signal representing the reconstructed image data is provided as an output of the MR system. The reconstructed image data may be stored and/or displayed. Advantageously, the correction can be employed flexibly for k-space trajectories with different frequency components.
Methods, systems, and computer readable media for in vivo phase incrementing magnetic resonance spectroscopic imaging (PI-MRSI) for multi-biomarker imaging and for simultaneous imaging of zero quantum—>double quantum (ZQ—>DQ) and DQ—>ZQ coherence pathways
Phase-incrementing MRSI (pi-MRSI) method has resolved overlapping biomarker images in the presence of a read-gradient. On a Bruker 9.4T MRI spectrometer, the pi-SEE-HSelMQC sequence was implemented. The choline-selective and lactate CH-selective RF pulses were phase incremented by 10° in opposite signs, synchronized with the phase-encoding steps. The lactate and choline images from a yogurt phantom displayed opposite image offsets without image overlapping. In vivo one-dimensional pi-SEE-HSelMQC CSI images of lactate and choline, acquired from the MDA-MB-231 human breast cancer xenograft in a nude mouse, as well as two-dimensional pi-SEE-HSelMQC imaging of lactate and choline acquired from the PC3 human prostate cancer xenograft in a nude mouse, also had opposite image offsets, shifted away from the spurious residual water signals in the image center. The pi-SEE-HSelMQC method completely suppresses lipid and water with potential clinical applications in disease diagnosis and therapeutic interventions.
MAGNETIC RESONANCE IMAGING APPARATUS AND MAGNETIC RESONANCE IMAGING METHOD
A magnetic resonance imaging apparatus includes sequence controlling circuitry and processing circuitry. The sequence controlling circuitry executes (i) a first pulse sequence in which a spatially selective Inversion recovery (IR) pulse and a spatially non-selective IR pulse are applied, and (ii) a second pulse sequence in which the spatially non-selective IR pulse is applied without applying the spatially selective IR pulse, while varying the first TI period, with respect to a plurality of first TI periods. The sequence controlling circuitry executes (iii) the third pulse sequence in which the spatially selective IR pulse and the spatially non- selective IR pulse are applied, and (iv) the fourth pulse sequence in which the spatially non-selective IR pulse is applied without applying the spatially selective IR pulse. The processing circuitry generates a magnetic resonance image of an imaged region based on data obtained from the third pulse sequence and the fourth pulse sequence.
Systems and methods for magnetic resonance based skull thermometry
Described herein are systems, methods, and computer-readable medium for magnetic resonance (MR) based thermometry. In one aspect, in accordance with one embodiment, a method for magnetic resonance based thermometry includes: acquiring, by a variable flip-angle T1 mapping sequence, MR data in an area of interest of a subject that is heated by the application of focused ultrasound (FUS) to the brain of the subject, where the MR data includes T1 values over time, and where the acquisition of the MR data includes applying an accelerated three-dimensional ultra-short spiral acquisition sequence with a nonselective excitation pulse; and determining, based at least in part on a mathematical relationship established by T1 mapping thermometry, a temperature change in the area of interest over time, and where the temperature change is caused at least in part by a change in the applied FUS.