Siemens Healthcare Gmbh

University College Cardiff Consultants Limited

University of Glasgow

Siemens Healthineers Ag

Robin Heidemann

Patrick Liebig

David Andrew Porter

Joseph Whittaker

Kevin Murphy

Fabrizio Fasano

The disclosure is directed to an Echo-Planar-Imaging (EPI) magnetic resonance imaging techniques combined with a variable-density undersampling scheme. The technique comprises generating an RF pulse, applying a switched frequency-encoding read out gradient in a variable time interval, and applying simultaneously an intermittently blipped low-magnitude phase-encoding gradient with a variable value of an integral of the phase-encoding gradient. The aforementioned steps are carried out such that the k-space is at least partially undersampled and the time interval of one read out gradient is varied depending on the integral of the phase encoding gradient, such that a ratio between the variable time interval of the read out gradient and the integral of the corresponding phase encoding gradient is kept above or at a predetermined constant value, which is related to a predetermined criteria of image quality.

Echo-spacing shuffling for echo-planar-imaging

In a method for readout segmented magnetic resonance imaging (MRI) of an examination object, k-space is acquired in a plurality of segments along a readout direction using a parallel imaging (PI) technique. K-space in a first segment is acquired with a first acceleration factor, and k-space in a second segment is acquired with a second acceleration factor different from the first acceleration factor.

Systems and methods for segment-specific data acquisition in readout-segmented magnetic resonance imaging

Techniques are disclosed for recording magnetic resonance data with a magnetic resonance facility, wherein a three-dimensional echo-planar imaging sequence is used whereby following a single excitation period (e.g. 'module') in an echo train, an echo count of k-space rows is read out in a read-out direction in the k-space, and interchanging takes place between these rows by means of gradient pulses of the two phase encoding directions.

Method for recording magnetic resonance data, magnetic resonance facility, computer program and electronically readable data carrier

A method for obtaining magnetic resonance imaging (MRI) echo-planar image (EPI) data, including providing a homogeneous, static background field; providing a gradient field to select a slice of an object for imaging; applying Radio-frequency (RF) pulses to excite magnetic resonance in the selected slice; and measuring a radio frequency signal emitted by the selected slice containing image data. The RF pulses are repeatedly applied separated by a time period shorter than a recovery time of static material in the selected slice such that the static material remains in a state of magnetic saturation, while dynamic material arriving within the slice since a previous RF pulse is not magnetically saturated.

Method for obtaining magnetic resonance imaging (MRI) echo-planar image (EPI) data

In a method and magnetic resonance (MR) apparatus for echo-planar MR imaging with which MR signals are entered in raw-data space with a zigzag-type trajectory, a sequence of readout gradients and phase-encoding gradients is applied such that a zigzag-type undersampled trajectory in raw-data space is filled, such that with the signal echoes being shifted by up to a quarter of the acquired raw-data space in the direction of the readout axis. Image data are reconstructed using a parallel-imaging reconstruction algorithm that operates on the raw data acquired in the zigzag-type trajectory, based on an interlaced Fourier transform.

Magnetic resonance method and apparatus for echo-planar imaging with a zigzag-type trajectory in raw-data space

In a method and magnetic resonance (MR) apparatus for echo-planar acquisition of MR images using multiple reception coils, an RF excitation pulse is radiated to generate transverse magnetization, and a temporal sequence of a readout gradient is activated with alternating positive and negative values, thereby producing MR signal echoes. Multiple phase-encoding gradients are activated in a temporal sequence with a value of the phase-encoding gradients being maximum when a value of the readout gradients is minimum, and vice versa. A time period during which a single phase-encoding gradient is applied is at least a quarter of a time interval between two MR signal echoes. The MR signal echoes are read with the multiple reception coils in a trajectory in k-space, continuously without interruption during the readout gradient. The trajectory does not completely fill k-space with raw data in an edge region according to the Nyquist condition.

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Litzendorf, Germany

Robin Heidemann