Described here are systems and methods for separating magnetic resonance signals that are changing over a scan duration (i.e., dynamic signals) from magnetic resonance signals that are static over the same duration. As such, the systems and methods described in the present disclosure can be used to remove artifacts associated with dynamic signals from images of static structures, or to better image the dynamic signal (e.g., pulsatile blood flow or respiratory motion).

To provide a technique in which, in imaging using an EPI method, an occurrence of an artifact when phase correction is performed for each channel is avoided and the phase correction is accurately performed. A common phase correction value to be applied to data of all channels is calculated using pre-scan data of each channel. The common phase correction value is obtained by combining a difference phase obtained for each of the channels. The difference phase is obtained by complex integration, while an absolute value of each channel is maintained as it is. The combination is performed by complex average, and averaging processing according to a weight of the absolute value is performed. The occurrence of an artifact can be prevented by using the common phase correction value, and robust phase correction can be performed by including the weight of the absolute value.

There are provided a parallel rapid imaging method and device based on a complex number conjugate symmetry of multi-channel coil data and nonlinear GRAPPA image reconstruction, and a medium. The imaging method includes: obtaining virtual conjugate coil data by expanding the actual multi-channel coil data; combining actual multi-channel coil data and virtual multi-channel coil data to obtain a linear data term and a nonlinear data term; calibrating weighting factors of the linear data term and the nonlinear data term by using combined low-frequency full-sampling data (margins of the low-frequency full-sampling data includes parts of high-frequency data); reconstructing data which is under-sampled in a high-frequency region according to the calibrated weighting factors; fusing the low-frequency full-sampling data and the reconstructed data for the high-frequency region.

A method and apparatus for determining spatial distribution of a complex radio frequency (RF) of both transmit field and receive sensitivity a magnetic resonance imaging (MRI) system. The method includes estimation of the absolute phase of transmit field using a reference transmit coil or array coils with minimal absolute phase. The method and apparatus include estimation of complex receive sensitivity of a transceiver coil using the complex transmit field of the transceiver coil or array coils.

A Computer-implemented method of reconstructing a dynamic series of motion-compensated magnetic resonance images of a patient is provided. Images of a patient are acquired over time, at least partially in free-breathing, at a first image resolution and on a frame-by-frame basis. Each frame of the k-space data includes a first subset of data points having a first sample density and a second subset of data points having a second sample density. For each frame, a sub-group of the first subset and the second subset of the k-space data is selected, and an image is reconstructed at a second image resolution. The motion between the second image resolution images is estimated in the form of motion fields. The motion information is incorporated into a final reconstruction of a dynamic series of motion-compensated magnetic resonance images of the patient at a third image resolution.

Appropriate processing is executed in a method for excluding body motion data and image reconstruction according to a type and a characteristic of a body motion, so as to reduce an influence of the body motion, and prevent deterioration of image quality caused by exclusion of data generated during the body motion. An MRI apparatus includes a processing determination unit that collects k-space data and acquires body motion information from a sensor capable of detecting not only a respiratory motion but also general body motions, analyzes the body motion information obtained by the sensor, and branches and executes processing for subsequent data collection and image reconstruction according to the analysis result. The MRI apparatus determines, based on a temporal characteristic such as a duration and a frequency, and a spatial characteristic of the body motion, particularly a generation pattern in a k-space, body motion data to be excluded, and executes image reconstruction suitable for k-space data after exclusion of the body motion data.

Techniques for compensating magnetic resonance imaging (MRI) data for artefacts caused by motion of a subject being imaged. The techniques include obtaining spatial frequency data obtained by using a magnetic resonance imaging (MRI) system to perform MRI on a patient, the spatial frequency data including first spatial frequency data and second spatial frequency data; determining a transformation using a first image obtained using the first spatial frequency data and a second image obtained using the second spatial frequency data; determining a residual spatial phase; correcting, using the transformation, second spatial frequency data and the residual spatial phase, to obtain corrected second spatial frequency data and a corrected residual spatial phase; and generating a magnetic resonance (MR) image using the corrected second spatial frequency data and the corrected residual spatial phase.

Systems and methods are provided for performing automated reconstruction of a dynamic MRI dataset that is acquired without a fixed temporal resolution. On one or more image quality metrics (IQMs) are obtained by processing a subset of the acquired dataset. In one example implementation, at each stage of an iterative process, one or more IQMs of the image subset is computed, and the parameters controlling the reconstruction and/or the strategy for data combination are adjusted to provide an improved or optimal image reconstruction. Once the IQM of the image subset satisfies acceptance criteria based on an estimate of the overall temporal fidelity of the reconstruction, the full reconstruction can be performed, and the estimate of the overall temporal fidelity can be reported based on the IQM at the final iteration.

A magnetic resonance (MR) image is created by executing an imaging sequence with an MR apparatus, wherein data in k-space are acquired using multiple receiving antennae, and reconstruction of all image points that correspond to all k-space points belonging to the imaging sequence takes place using a sensitivity profile of the receiving antennae in order to also take account of data at k-space points at positions at which no data were acquired. Data acquired at a number of positions of particular k-space points, the number of the particular k-space points being smaller than the number of all k-space points belonging to the imaging sequence. The aperture of each of the receiving antennae is configured such that, for acquisition of data at a respective k-space point, the spectral main lobe of the respective receiving antenna also extends over k-space points adjacent to the respective k-space point.

In a method and magnetic resonance (MR) apparatus for establishing imaging sequence parameter values with a reduced eddy current formation for flow-encoded magnetic resonance imaging, a number of different flow-encoded candidate raw datasets are acquired by executing a flow-encoded gradient measurement sequence with different imaging sequence parameter values from a test or calibration region of an examination object. Flow-encoded candidate image datasets are reconstructed from the different flow-encoded candidate raw datasets. A flow-encoded candidate image dataset is selected as a function of a background phase contrast established in a phase-contrast image assigned to the respective flow-encoded candidate image dataset. The imaging sequence parameter values assigned to the flow-encoded candidate image dataset are selected as parameter values for an imaging sequence for subsequent diagnostic flow-encoded magnetic resonance imaging.