The invention relates to a method of MR imaging of an object (10). It is an object of the invention to enable MR imaging in the presence of motion of the imaged object, wherein full use is made of the acquired MR signal and a high-quality MR image essentially free from motion artefacts is obtained. The method of the invention 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 as signal data over a given period of time (T); subdividing the period of time into a number of successive time segments (SO, S1, S2, . . . Sn); deriving a geometric transformation (DVF1, DVF2, . . . DVFn) in image space for each pair of consecutive time segments (S0, S1, S2, . . . Sn), which geometric transformation (DVF1, DVF2, . . . DVFn) reflects motion occurring between the two time segments of the respective pair; and reconstructing an MR image from the signal data, wherein a motion compensation is applied according to the derived geometric transformations (DVF1, DVF2, . . . DVFn). Moreover, the invention relates to an MR device (1) and to a computer program for an MR device (1).

In a method for improved recording of scan data of an examination object by means of a magnetic resonance system with the aid of a simultaneous multi-slice (SMS) method, a minimum repetition time TR is determined dependent upon a quality criterion. The quality criterion herein extends the scan time, which is actually greatly shortened by the use of an SMS method, for the MR signals of the slice stack to be recorded, to the minimum repetition time TR. The “time reserve” thereby obtained (the difference of the determined minimum repetition time TR from the scan time needed for the slice stack to be recorded purely by means of the SMS method) is utilized to take account of further slices in the recording of the MR signals. By this means, firstly, further information can be obtained and, secondly, the image quality of the image data obtained is improved.

A method of performing multidimensional magnetic resonance imaging on a subject comprises collecting imaging data for a region of interest of the subject, the imaging data related to one or more spatially-varying parameters of the subject within the region of interest; collecting auxiliary data for the region of interest in the subject, the auxiliary data related to one or more time-varying parameters of the subject within the region of interest; linking the imaging data and the auxiliary data; and constructing an image tensor with one or more temporal dimensions based on at least a portion of the linked imaging data and at least a portion of the linked auxiliary data.

A method for acquiring magnetic resonance imaging data with respiratory motion compensation using one or more motion signals includes acquiring a plurality of gradient-delay-corrected radial readout views of a subject using a free-breathing multi-echo pulse sequence, and sampling a plurality of data points of the gradient-delay-corrected radial readout views to yield a self-gating signal. The self-gating signal is used to determine a plurality of respiratory motion states corresponding to the plurality of gradient-delay-corrected radial readout views. The respiratory motion states are used to correct respiratory motion bias in the gradient-delay-corrected radial readout views, thereby yielding gradient-delay-corrected and motion-compensated multi-echo data. One or more images are reconstructed using the gradient-delay-corrected and motion-compensated multi-echo data.

Techniques for determining motion states of at least two bodies by an MR-device are provided, wherein the bodies each have a respective target region which is in an anatomic motion comprising a repetitive motion pattern with a motion repetition rate, and in particular, for cardiac and/or respiratory motion. A sequence of individual MR-measurements are performed on the bodies at a MR-repetition rate higher than the motion-repetition rate, wherein nuclear spins of the at least two bodies are excited during the sequence of individual MR-measurements either simultaneously or alternately at navigator times. With the individual MR-measurements, navigator signals are determined, each respective navigator signal indicative of the motion state of at least one of the motion patterns at the navigator time of the navigator signal. These techniques allow simultaneously determining motion states for imaging more than one body with a repetitive motion pattern with reduced preparation time.

A computer-implemented method of reconstructing a motion-compensated magnetic resonance image uses raw k-space data acquired at a first resolution over successive respiratory and/or cardiac cycles of a patient. After binning data based on corresponding motion states derived from these cycles, the resolution of the binned K-space data in each bin is reduced. This is done by selecting a sub-group of binned k-space data. Bin images are reconstructed from the reduced-resolution data, and histogram-equalised versions of the reconstructed reduced-resolution bin image generated for each bin. Motion fields are estimated and interpolated to the first resolution such that motion data can be incorporated into a final reconstruction of a motion compensated image.

A method of controlling magnetic resonance (MR) image data acquisition includes generating a plurality of one-dimensional (1D) navigator profiles reflecting motion of an anatomic boundary region of an imaging subject over time at a measurement interval, and then generating a plurality of navigator image segments each for a corresponding 1D navigator profile of the plurality of 1D navigator profiles. A navigator image is then generated based on the plurality of navigator image segments, and a determination is made whether to acquire MR image data based on the navigator image.

A method for reordering a segmented MRI pulse sequence includes synchronizing to a physiologic signal of a heart or vessel, to a respiratory signal, or to an external trigger source, and acquiring a plurality of data collecting segments as a contiguous block in a phase encoding direction such that lines of the plurality of data collecting segments are alternately acquired in a forward direction and a reverse direction for each consecutive data collecting segment.

A method for creating a roadmap for a medical workflow includes providing a multidimensional image-dataset including a plurality of images of a predefined organ combined with a number of state-dimensions characterizing a movement state of a moving organ. Measured pilot tone data is provided from a continuous pilot tone signal acquisition. A coordinate is determined for each state-dimension based on the measured pilot tone data, and an image of the multidimensional image-dataset is selected based on the number of determined coordinates of each state dimension.

A method for acquiring magnetic resonance imaging data with respiratory motion compensation using one or more motion signals includes acquiring a plurality of gradient-delay-corrected radial readout views of a subject using a free-breathing multi-echo pulse sequence, and sampling a plurality of data points of the gradient-delay-corrected radial readout views to yield a self-gating signal. The self-gating signal is used to determine a plurality of respiratory motion states corresponding to the plurality of gradient-delay-corrected radial readout views. The respiratory motion states are used to correct respiratory motion bias in the gradient-delay-corrected radial readout views, thereby yielding gradient-delay-corrected and motion-compensated multi-echo data. One or more images are reconstructed using the gradient-delay-corrected and motion-compensated multi-echo data.