Siemens Aktiengesellschaft

Siemens Healthcare Gmbh

Siemens Healthineers Ag

De He Weng

Kun Zhou

Fang Dong

Qiang He

Qiong Zhang

Jin Qiang He

Nan Xiao

David Grodzki

Stephan Biber

Wei Jun Zhang

Yan Huang

Jian Wang

Yu Wang

Le Zhang

Xiao Dong Zhou

Shu Qun Xie

Jing An

Shi Cheng

Zhong Qiang Shi

In a magnetic resonance imaging method, a first adjustment parameter is determined for presetting an initial contrast of a magnetic resonance image; a second adjustment parameter is determined for obtaining an optimized contrast of the magnetic resonance image and a specified data acquisition time of a blade artifact correction sequence; an optimized echo signal evolution curve is determined according to the first adjustment parameter and the second adjustment parameter; an actual variable flip angle train is calculated according to the optimized echo signal evolution curve; and the actual variable flip angle train is applied to a two-dimensional fast spin echo sequence, and the blade artifact correction sequence corresponding to the second adjustment parameter is used to acquire magnetic resonance signals and enable the magnetic resonance image to satisfy the optimized contrast.

Magnetic resonance imaging method and apparatus based on two-dimensional fast spin echo

The present disclosure provides techniques for determining a respiration phase by extracting a distance characteristic value, a score characteristic value, and an area characteristic value from the respiration signal, wherein the distance characteristic value, the score characteristic value and the area characteristic value are used to indicate waveform variation between two adjacent waveforms in the respiration signal. The techniques include training a respiration signal model according to the distance characteristic value, the score characteristic value, and the area characteristic value to determine the respiration phase of the respiration signal using the respiration signal model.

Method and apparatus for determining respiration phase, magnetic resonance imaging method and system

The disclosure relates to techniques for triggering magnetic resonance data acquisition. The techniques include detecting a respiration direction of a respiration signal of an acquisition subject, predicting in real time an amplitude peak value of an expiration signal in the current respiration period according to the real-time respiration signal of the acquisition subject, multiplying the amplitude peak value by a preset coefficient, and using the product as a trigger point threshold of the current respiration period. When it is determined that an expiration stage of the current respiration period is starting, the techniques also include calculating in real time or periodically the absolute value of the difference between the amplitude of the current expiration signal and the trigger point threshold currently calculated, and if the absolute value of the difference is less than a preset difference threshold, then triggering MR data acquisition.

Respiratory modeling using deep learning for MR imaging with pilot tone navigation

The present disclosure is directed to MRI techniques. The techniques include occupying a central region of a first k-space with full sampling along a Cartesian trajectory, occupying a peripheral region of the first k-space with undersampling along a non-Cartesian trajectory; acquiring sensitivity distribution information of receiving coils; based on a sensitivity distribution chart, merging the Cartesian data of the central region according to multiple channels to obtain a third k-space; based on the sensitivity distribution chart, applying parallel imaging and compressed sensing to the undersampled non-Cartesian trajectory to reconstruct an image, obtaining a second k-space by transformation, and when the second k-space and third k-space are synthesized, using a central region of the second k-space to replace the third k-space of a corresponding region to obtain a k-space suitable for image reconstruction.

Magnetic resonance imaging method and magnetic resonance imaging system

In a MR water-fat image separation method and device, within one echo period, a first echo set under a first readout gradient polarity and a second echo set under a second readout gradient polarity are acquired. The first and second readout gradient polarities may be opposite, and echoes in the first echo set may be positionally one-to-one symmetric to echoes in the second echo set with respect to the echo center of the echo period. A first echo image set is obtained based on first echo set data acquired in each echo period, and a second echo image set is obtained based on second echo set data acquired in each echo period. Using the first and second echo image sets, a Dixon water-fat separation calculation is performed to obtain a water image and a fat image. The method and device can advantageously increase acquisition efficiency and the signal-to-noise ratio.

Magnetic resonance water-fat image separation method and apparatus, imaging system and storage medium

In a method for correcting the interference in respiratory navigation, transmitting, during magnetic resonance scanning, a respiratory signal generated by a radio frequency signal generator to a human body; acquiring, as a measured respiratory signal, a respiratory signal passing through the human body and acquired in a local coil, wherein the measured respiratory signal is constituted by a real respiratory signal and an interference signal; determining, according to a respiratory signal coil sensitivity of the real respiratory signal and an interference signal coil sensitivity of the interference signal, a signal relation that is satisfied by the real respiratory signal, the interference signal and the measured respiratory signal; and calculating the signal relation to obtain the real respiratory signal.

Method and apparatus for correcting interference in respiratory navigation, and storage medium

The present application describes techniques for determining and eliminating a time delay between a radio frequency pulse and a layer selection gradient in a magnetic resonance device. The techniques for determining and eliminating the time delay direct include measuring the time delay between the layer selection gradient and the radio frequency pulse by using phase information. This technique is more sensitive and accurate than existing methods that use signal or artifact strength.

Method for determining and eliminating time delay between radio frequency pulse and layer selection gradient in a magnetic resonance device

A method and a magnetic resonance imaging device, and a corresponding computer readable storage medium. The method includes acquiring a distortion function describing a frequency dependence of an amplitude or phase of an MR-signal received by a receiver part of the MRI-device, Fourier transforming K-space data acquired using this receiver part to image space data, generating compensated image space data by compensating for the frequency dependence by dividing the image space data or image space data derived therefrom in image space by the distortion function, and providing the MR-image as the compensated image space data or reconstructed therefrom.

Method and magnetic resonance imaging device for providing an MR-image, computer program, and computer-readable storage medium

In a method, apparatus and storage medium for filling a k-space trajectory in magnetic resonance (MR) imaging, a blank window, following an RF excitation pulse, is set in an arbitrary spatial encoding direction, and a first MR signal is acquired in this blank window, to obtain the phase of the first MR signal. A gradient field is activated outside the blank window and a second MR signal is acquired to obtain the phase of the second MR signal. This first and second MR signals are entered into k-space along first k-space and second k-space trajectories that are respectively based on the phase of the first MR signal and the phase of the second MR signal. A calibrated k-space trajectory in the spatial encoding direction is determined based on the first and second k-space trajectories.

Method, device and storage medium for scanning a k-space trajectory in magnetic resonance imaging

In a magnetic resonance angiography method and apparatus, a time-of-flight sequence is used to acquire and enter k-space data, and a magnetic resonance angiography image is reconstructed from the k-space data. The time-of-flight sequence includes at least one saturation radio frequency pulse and multiple excitation radio frequency pulses. At least two of the excitation radio frequency pulses directly follow the saturation radio frequency pulse, and part of the k-space data is collected after each of the excitation pulses. Scanning time can thus be decreased, scanning efficiency can be improved, the electromagnetic absorption ratio can be reduced, and a venous magnetic resonance signal is still suppressed.

Magnetic resonance angiography method and apparatus

In a trajectory correction method and apparatus for k-space data points in magnetic resonance imaging, a magnetic resonance data acquisition unit is operated to execute a sampling sequence to obtain k-space to be corrected. Empirical points are selected used to divide k-space to be corrected into a central region and a peripheral region. The trajectories of the data points in the central region and the peripheral region are corrected and the sampling sequence is executed again, with the corrected trajectories, to obtain corrected k-space.

Trajectory correction method and apparatus for k-space data in magnetic resonance imaging

In a magnetic resonance imaging method and apparatus for water/fat separation, a turbo spin echo BLADE (TSE BLADE) artifact correction sequence is executed to acquire original data for an in-phase image and original data for an opposite-phase image, and an in-phase image on the basis of the original data for the in-phase image and an opposite-phase image on the basis of the original data for the in-phase image and the original data for the opposite-phase image are reconstructed. Water and fat images are calculated on the basis of the reconstructed in-phase image and opposite-phase image. By using a TSE BLADE sequence to acquire k-space data, the advantage of the BLADE sequence of being insensitive to rigid body motion and pulsation is inherently present, thereby reducing sensitivity to motion artifacts while improving the image signal-to-noise ratio.

Magnetic resonance imaging method and device achieving water/fat separation

For magnetic resonance imaging (MRI), a dynamic frequency drift correction method for binomial water excitation method includes collecting the reference one-dimensional navigation signal by an MRI device; acquiring one current one-dimensional navigation signal after scanning N images, wherein N is a positive integer; calculating the frequency drift according to the reference one-dimensional navigation signal and the current one-dimensional navigation signal; calculating and setting the initial phase of the next radio frequency signal by the MRI device according to the frequency drift. The method provides real-time calculation of the main magnetic field frequency drift according to the one-dimensional navigation signal during the scanning period and corrects the phase of the radio frequency signal to ensure that the direction of the gradient field is always perpendicular to the plane formed by the spinning of fat protons, so there is only water signal remaining after excitation so that water images can be obtained.

Dynamic frequency drift correction method in magnetic resonance imaging

In a method and an apparatus for making a distinction in a magnetic resonance imaging water-fat image, three echoes are acquired without phase encoding as a reference scan, a reference water-fat image projection is calculated in the phase encoding direction using the reference scan, a complete water-fat image projection is calculated in the phase encoding direction according to a water image and a fat image obtained by a three-point Dixon method, a correlation between the reference water-fat image projection and the complete water-fat image projection is calculated to obtain at least two correlated values, and the maximum correlated value is acquired therefrom, so as to determine the type of said image calculated by using the three-point Dixon method.

Method and apparatus for making distinction in a magnetic resonance imaging water-fat image

In a method and system for echo planar imaging, after having applied a radiofrequency pulse and a slice selection gradient, continuous readout gradients alternating between positive and negative are applied and a phase encoding gradient is applied before starting each readout gradient. A slice selection gradient is applied at the same time as applying the phase encoding gradient. Scanning signals are collected during the duration of the readout gradients. Image reconstruction is implemented based on the scanning signals to obtain a scanned image.

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Shenzhen, China

De He Weng