In a method and apparatus for performing magnetic resonance (MR) imaging for generating multiple T1 maps of separate regions of interest of a subject along a first spatial axis, multiple MR pulse sequences are generated, each MR pulse sequence being for imaging a respective one of the separate regions of interest of the subject. In order to generate each of the plurality of MR pulse sequences, a spatially selective preparation pulse is generated exciting the region of interest of the subject and a number of imaging sequences that follow the application of the spatially selective preparation pulse are generated. MR imaging data are acquired during the generation of the multiple imaging sequences. The multiple MR pulse sequences are generated during a period not exceeding 30 seconds.

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.

A method for motion correction of Magnetic Resonance (MR) images is provided. The method includes acquiring a k-space dataset for an object using an MR scanner, detecting or identifying corrupted k-space data from the acquired k-space dataset, extracting the corrupted k-space data from the acquired k-space dataset, recovering the corrupted k-space data, combining uncorrupted k-space data of the acquired k-space dataset with the recovered k-space data to form a full k-space dataset, and reconstructing an image for the object based on the full k-space dataset. A magnetic resonance imaging system for correcting corrupted k-space data of an entire k-space dataset is also provided.

A subject information acquisition apparatus, comprises: a signal generation unit configured to generate a high-frequency signal corresponding to each of the frequencies; an acquisition unit configured to acquire a plurality of detection signals based on at least one of a reflection signal and a transmission signal; a signal selection unit configured to select at least one detection signal from the plurality of detection signals based on an index value of the plurality of detection signals; a coupling amount detecting unit configured to detect a coupling amount of near-field coupling due to an electric field between the antenna and the subject based on a detection signal; and a displacement detecting unit configured to generate a displacement signal indicating a displacement of the subject based on the coupling amount.

In a method for reconstructing magnetic resonance (MR) image data from k-space data, k-space data of an image region of a subject are provided to a computer that is also provided with multiple navigator signals for the image region of the subject. The computer sorts the k-space data into multiple bins, the multiple bins representing different motion states of the subject. For each of the multiple bins, the computer executes a compressed sensing procedure to reconstruct the MR image data from the k-space data in the respective bin. Execution of the compressed sensing procedure includes solving an optimization problem comprising a data consistency component and a transform sparsity component. Motion information is incorporated by the computer into at least one of the data consistency component and the transform sparsity component of the optimization problem.

A control device establishes a change in a main magnetic field expected for a respective time instant and based on the established expected change in the main magnetic field, correctively adjusts the main magnetic field and/or a nominal receive frequency of the RF receive coil and/or a transmit frequency for subsequent RF transmit pulses and/or takes the expected change in the main magnetic field into account in the evaluation of the received MR signals. At least for some of the RF transmit pulses, the control device acquires, via a sensor device, a portion of the respective radiofrequency wave supplied to the RF transmit coil. The controller extracts therefrom an oscillation corresponding to a respiratory motion of the patient and based on the variation with time of the extracted oscillation, establishes the change in the main magnetic field expected for the respective time instant.

A method for proton resonance frequency shift (PRF) and T.sub.1-based temperature mapping using a magnetic resonance imaging (MRI) system includes acquiring, using the MRI system, a set of magnetic resonance (MR) data from a region of interest of a subject by performing a variable-flip-angle multi-echo gradient-echo 3D stack-of-radial pulse sequence. The pulse sequence is configured to acquire radial k-space data in a plurality of segments, each segment acquired with each of a plurality of flip angles. The method further includes generating at least one T.sub.1 map based on the set of MR data, generating at least one PRF temperature map based on the set of MR data, generating at least one T.sub.1-based temperature map based on the set of MR data and displaying the PRF temperature map and the T.sub.1-based temperature map. In another embodiment, the MR data may be used to generate a plurality of quantitative parameter maps for each of the plurality of MR parameters such as T.sub.1, proton-density fat fraction (PDFF), and R.sub.2*.

A method for acquiring a magnetic resonance data set of an object under examination by a magnetic resonance system using a scan sequence is provided. The scan sequence includes a succession of sequence blocks, and in each sequence block, there is at least one sub-block including an excitation section and/or a detection section. An excitation section includes at least one excitation pulse, and in a detection section, an echo signal or an echo train is acquired as a scan signal. At least one item of motion information is provided for each sub-block. The motion information contains information about a movement of the object under examination within a duration of the sub-block. Some of the sub-blocks are automatically repeated. At least the sub-blocks having motion information that exceeds a threshold value are repeated. The threshold value defines a motion amplitude.

A magnetic resonance (MR) imaging device repeatedly executes a navigator pulse sequence to generate navigator data in image space as a function of time, and a motion signal of an anatomical feature that moves with a physiological cycle as a function of time is extracted from the navigator data. A concurrent physiological signal as a function of time is generated by a physiological monitor concurrently with the repeated execution of the navigator pulse sequence. A gating time offset is determined by comparing the motion signal of the anatomical feature as a function of time and the concurrent physiological signal as a function of time. The MR imaging device performs a prospective or retrospective gated MR imaging sequence using gating times defined as occurrence times of gating events detected by the physiological monitor modified by the gating time offset.

The invention relates to a method of MR imaging of an object (10). It is an object of the invention to enable MR imaging using a 3D radial or spiral acquisition scheme providing an enhanced image quality in the presence of motion. The method comprises the steps of: —generating MR signals by subjecting the object (10) to an imaging sequence comprising RF pulses and switched magnetic field gradients; —acquiring the MR signals using a 3D radial or spiral acquisition scheme with oversampling of a central portion (26) of k-space; —detecting motion-induced displacements (d) and/or deformations of the object (10) during the acquisition of the MR signals and assigning each of the acquired MR signals to a motion state; —reconstructing an MR image from the MR signals weighted in the central portion (26) of k-space, wherein a stronger weighting (W, 30) is applied to MR signals acquired in more frequent motion states, while a weaker weighting (W, 31, 32) is applied to MR signals acquired in less frequent motion states. Moreover, the invention relates to a MR device (1) and to a computer program for a MR device (1).