Techniques are disclosed related to the compensation of phase variations introduced into k-space lines, which cause imaging artifacts. The techniques utilize the detection of motion via an encoding plus motion model, which does not require the use of additional prospective or retrospective motion detection techniques. The techniques described herein use the encoding plus motion model to reconstruct an initial image from a set of motion states, and then calculate phase information from images that are projected form the initial reconstructed image using a projection onto convex sets (POCS). The phase information is incorporated into the encoding plus motion model over several iterations to minimize data consistency error, thereby generating a refined image that compensates for patient motion over the set of motion states.

The disclosure relates to a magnetic resonance imaging device configured to exert a high-frequency electromagnetic field on an object under test in a static magnetic field and to reconstruct an image based on magnetic resonance signals. The magnetic resonance imaging device comprises a receiving coil comprising a plurality of receiving coil elements and configured to receive magnetic resonance signals and feed the magnetic resonance signals to a receiver, and a coupler configured to be coupled with at least a first receiving coil element of the receiving coil, the coupler being directionally coupled with at least the receiver, the first receiving coil element being configured to receive a high-frequency electromagnetic wave signal through the coupler. The directional coupling between the coupler and the receiver is so regulated that the first receiving coil element transmits the high-frequency electromagnetic wave signal to the object under test to sense a physiological movement signal.

A method and system are provided for detecting a position of a periodically moving organ in a MRI examination. MR images of an examining person including a periodically moving organ are provided over a plurality of periodic cycles of the periodically moving organ. Based on the provided MR images, a pixel frequency is associated with each pixel of the MR images. Using the associated pixel frequencies and the positions of the pixels within the MR images, the position and the frequency of the periodically moving organ are determined.

The present disclosure related to techniques for extracting a respiratory navigation signal for use in a magnetic resonance imaging system. The extracted respiratory navigation signals accurately represent respiratory motions of a patient.

The invention provides for a magnetic resonance imaging system (100, 200) comprising a memory (148) for storing machine executable instructions (150) and pulse sequence commands (152). The pulse sequence commands are configured for acquiring a four dimensional magnetic resonance data set (162) from an imaging region of interest (109). The four dimensional magnetic resonance data set is at least divided into three dimensional data magnetic resonance data sets (400, 402, 404, 406, 408) indexed by a repetitive motion phase of the subject. The three dimensional data magnetic resonance data sets are further at least divided into and indexed by k-space portions (410, 412, 414, 416, 418, 420, 422, 424, 426, 428, 430, 432, 434, 436). The magnetic resonance imaging system further comprises a processor (144) for controlling the magnetic resonance imaging system. Execution of the machine executable instructions causes the processor during a first operational portion (310) to iteratively: receive (300) a motion signal (156) descriptive of the repetitive motion phase; acquire (302) an initial k-space portion using the pulse sequence commands, wherein the initial k-space portion is selected from the k-space portions; store (304) the motion signal and the initial k-space portion in a buffer (158) for each iteration of the first operational portion; at least partially construct (306) a motion phase mapping (160) between the motion signal and the repetitive motion phase; and continue (308) the first operational portion until the motion phase mapping is complete. Execution of the machine executable instructions causes the processor to assign (312) the initial k-space portion for each iteration of the first operational portion in the temporary buffer to the four dimensional magnetic resonance data set using the motion phase mapping. Execution of the machine executable instructions causes the processor during a second operational portion (332) to iteratively: receive (314) the motion signal; determine (316) a predicted next motion phase using the motion signal and the motion phase mapping; select (318) a subsequent k-space portion (154) from the k-space portions of the four dimensional magnetic resonance data set using the predicted next motion phase; acquire (320) the subsequent k-space portion using the pulse sequence commands; rereceive (322) the motion signal; determine (324) a current motion phase using the re-received motion signal and the motion phase mapping; assign (326) the

An object of the present invention is to provide an MRI apparatus capable of optimally setting imaging conditions for map measurement depending on a target value and its required accuracy, and a method for controlling the MRI apparatus. An imaging unit of the MRI apparatus includes, as a pulse sequence, a pulse sequence for the T1 map measurement that includes a first signal acquisition sequence and a plurality of signal acquisition sequences executed after application of an inverted pulse and at different signal acquisition times from the inverted pulse. An imaging controller of the MRI apparatus controls the imaging conditions of each of the plurality of signal acquisition sequences, for example, the signal acquisition time from the inverted pulse and the number of signal acquisition sequences depending on the T1 value of an imaging target and the required accuracy.

A method and system provides an acquisition scheme for generating magnetic resonance elastography displacement data with whole-sample coverage, high spatial resolution, and adequate SNR in a short scan time. The method and system can acquire in-plane and through-plane k-space shots over a volume of a sample divided into a plurality of slabs that each include a plurality of non-adjacent slices to obtain three dimensional multiband, multishot data, can apply multiband radio frequency refocusing pulses to the sample, can acquire navigators before readout, and can correct for non-linear motion errors.

A trained deep learning network is for determining a cardiac phase in magnet resonance imaging. In an embodiment, the trained deep learning network includes an input layer; an output layer; and a number of hidden layers between input layer and output layer, the layers processing input data entered into the input layer. In an embodiment, the deep learning network is designed and trained to output a probability or some other label of a certain cardiac phase at a certain time from entered input data. A method for determining a cardiac phase in magnet resonance imaging; a related device; a training method for the deep learning network; a control device and a related magnetic resonance imaging system are also disclosed.

A method of reconstructing magnetic resonance (MR) image data from k-space data. The method includes obtaining k-space data of an image region of a subject; and reconstructing, using a sparse image coding procedure, the MR image data from the k-space data by performing an iterative optimization method. The optimization method includes a data consistency iteration step and a denoising iteration step applied to MR image data generated by the data consistency iteration step. The denoising iteration step incorporates a sparsifying operation to provide a sparse representation of the MR image data for the imaged region as an input to the data consistency iteration step.

A method for generating a movement signal of a body part, of which at least a portion is undergoing a cardiac movement, includes providing a pilot tone signal acquired from the body part by a magnetic resonance receiver coil arrangement. A demixing matrix is calculated from a calibration portion of the Pilot Tone signal using an independent component analysis algorithm. The independent component corresponding to the cardiac movement is selected. The demixing matrix is applied to further portions of the pilot tone signal to obtain a movement signal representing the cardiac movement. An, adaptive stochastic, or model-based filter is applied to the signal representing the cardiac movement, to obtain a filtered movement signal.