G01R33/4835

System and method for time of flight imaging with a tight sequence diagram pattern
11579226 · 2023-02-14 · ·

A Time-of-flight (TOF) MRI scanning method may include: a TOF MRI scan including a first slice selection gradient applied in the Z direction at the same time as an RF pulse being applied to an imaging target; after applying the RF pulse and first slice selection gradient has ended, applying a slice selection encoding gradient and a phase encoding gradient in the Z direction and Y direction respectively; when application of the slice selection encoding gradient and phase encoding gradient ends, applying a readout gradient in the X direction; when application of the readout gradient ends, applying a tracking saturation pulse to the imaging target, and simultaneously applying a second slice selection gradient in the Z direction; when application of the tracking saturation pulse ends, applying a spoiler gradient in the X, Y and/or Z directions of the magnetic field. The method advantageously reduces the TOF MRI scanning time.

Determining calibration data for a reconstruction of image data from scan data acquired by means of a magnetic resonance system
11709217 · 2023-07-25 · ·

Calibration data is determined for a reconstruction of image data from scan data acquired via a magnetic resonance system. This includes specifying acquisition shots for an acquisition of desired scan data in which acquisition shots scan data is acquired after radiating-in an RF excitation pulse, identifying first acquisition shots among the acquisition shots specified in which scan data is acquired in a central region in k-space, stipulating a sequence in which the specified acquisition shots are to be carried out such that first acquisition shots are arranged in the sequence in a starting portion to be carried out first, acquiring the scan data by carrying out the specified acquisition shots in the stipulated sequence, determining calibration data from scan data acquired in the starting portion of the sequence, and reconstructing image data using the acquired scan data and the specified calibration data.

MULTI-PURPOSE GRADIENT ARRAY FOR MAGNETIC RESONANCE IMAGING
20180011156 · 2018-01-11 ·

A system for multi-slice magnetic resonance imaging (MM) comprises a gradient coil array comprising a plurality of independent coils distributed about an enclosure; and a controller configured to concurrently actuate said plurality of coils so as to generate a spatially-varying magnetic field within said enclosure such that for at least first and second volumetric slices, a magnetic field magnitude associated with at least one location in the first volumetric slice is substantially equal to a magnetic field magnitude associated with a respective location in the second volumetric slice.

Methods and systems for estimating transmit attenuation for a magnetic resonance imaging scan

Various methods and systems are provided for correcting transmit attenuation of an amplifier of a transmit radio frequency (RF) coil for use in a magnetic resonance imaging (MRI) system. In one example, a method includes setting a reference value of transmit attenuation for an amplifier of a transmit radio frequency (RF) coil, acquiring a three-dimensional B.sub.1 field map with the transmit attenuation set at the reference value, determining a plurality of mean flip angles for a plurality of slice locations in a pre-scan imaging volume from the B.sub.1 field map, determining a transmit attenuation correction value for each of the slice locations based on a prescribed flip angle and the mean flip angle determined for the respective slice location, correcting the reference value of transmit attenuation with the transmit attenuation correction value at each of the slice locations to obtain a final value of transmit attenuation for each of the slice locations, and performing an MRI scan with the transmit attenuation set at the value.

Method for acquiring reference data for a phase correction in magnetic resonance technology
11698431 · 2023-07-11 · ·

In a method and system for acquiring measurement data reference data for a phase correction of the measurement data, a RF excitation pulse is provided to excite spins in the object under examination, one or more RF refocusing pulses are provided to refocus the spins excited by the RF excitation pulse, measurement data is acquired by recording echo signals of refocused spins excited by the RF excitation pulse by switching readout gradients that alternate in their polarity, at least two echo signals are recorded while switching readout gradients with different polarity acquire reference data, chronologically between the providing of the RF excitation pulse and the acquisition of the measurement data, and correction data is determined for phase correction of phase errors contained in the measurement data based on the acquired reference data.

Magnetic resonance imaging apparatus and imaging processing method for determining a region to which processing is to be performed
11550012 · 2023-01-10 · ·

A magnetic resonance imaging apparatus according to an embodiment executes a first imaging prior to a second imaging and includes processing circuitry. The processing circuitry receives, on a first image obtained from the first imaging, a setting of a region in which an RF (Radio Frequency) pulse is to be applied to a subject, generates a three-dimensional image based on the first image, determines, based on an imaging purpose of the second imaging, a translucent region to which translucent processing is to be performed in the three-dimensional image, and displays the translucent region, making the translucent region translucent in the three-dimensional image.

Method for Improved Positioning of Slices in Which Measurement Data is to be Recorded Using a Magnetic Resonance System
20230213602 · 2023-07-06 · ·

In a method to improved positioning of slices in which measurement data is to be recorded, a planning image of an examination object is provided that has been distortion-corrected using non-linearity data describing a non-linearity of a gradient unit of the magnetic resonance system, a desired field of view and desired slices in the at least one planning image are selected, a measurement protocol to record the measurement data is loaded, switchable gradients and/or emittable RF pulses are adapted, as a function of the non-linearity data that has been loaded and the desired slices, such that the desired slices are excited despite the non-linearities of the gradient unit, and the loaded measurement protocol is performed in the selected field of view, using the adapted gradients to be switched and/or adapted RF pulses. The measurement protocol may include switchable gradients and the emittable RF pulses.

Methods for scan-specific k-space interpolation reconstruction in magnetic resonance imaging using machine learning

Methods for reconstructing images from undersampled k-space data using a machine learning approach to learn non-linear mapping functions from acquired k-space lines to generate unacquired target points across multiple coils are described.

Magnetic resonance imaging apparatus, imaging parameter determining method, and non-volatile computer-readable storage medium storing therein imaging parameter determining program

A magnetic resonance imaging apparatus according to an embodiment includes processing circuitry configured, on a basis of one or both of (A) a parameter related to applying one of inversion and flip pulses and (B) an intensity of a slice selecting gradient magnetic field applied together with the one of the pulses in relation to selecting a slice to which the one of the pulses is applied, to determine one or both of (A) a parameter related to applying the other of the inversion and (B) flip pulses; and an intensity of the slice selecting gradient magnetic field applied together with the other of the pulses in relation to selecting a slice to which the other of the pulses is applied.

SYSTEMS AND METHODS FOR SIMULTANEOUS MULTI-SLICE IMAGING

A method for SMS imaging may include obtaining target k-space data related to a region of interest (ROI) of an object. The method may also include generate, based on the target k-space data using a trained reconstruction model, a plurality of target images each of which corresponds to one of a plurality of target slices of the ROI at one of a plurality of target acquisition periods.