A method for avoiding artifacts in measurement data captured using a magnetic resonance system which has a gradient unit. The method includes loading data which characterizes the gradient unit of the magnetic resonance system; loading a measurement protocol to be used for capturing the measurement data, wherein the measurement protocol includes gradients to be switched and RF excitation pulses and RF refocusing pulses to be irradiated, wherein, after irradiation of an RF excitation pulse, a train of at least two RF refocusing pulses is irradiated and measurement data is captured after each RF refocusing pulse; determining compensation gradients which, after the capture of the measurement data, are to be switched after a final RF refocusing pulse of the train of RF refocusing pulses associated with the RF excitation pulse and before a following RF excitation pulse as a function of the loaded measurement protocol and of the data which characterizes the gradient unit; and carrying out the measurement protocol using the determined compensation gradients.

Methods and systems are provided for identifying radio frequency (RF) interference without an RF room during imaging in a magnetic resonance tomography system. The method includes performing an acquisition, wherein scanning of a k-space along a trajectory takes place and an angle of rotation α exists between a scan start position of a first individual acquisition and a scan start position of a following second individual acquisition. A first image is obtained from the first individual acquisition and a second image is obtained from the second individual acquisition. One of the two images is rotated in respect of the other image about the angle of rotation α. A correlation is determined between the one rotated image and the other image, and a point of interference is identified from the correlation.

Methods and systems are provided for identifying radio frequency (RF) interference without an RF room during imaging in a magnetic resonance tomography system. The method includes performing an acquisition, wherein scanning of a k-space along a trajectory takes place and an angle of rotation α exists between a scan start position of a first individual acquisition and a scan start position of a following second individual acquisition. A first image is obtained from the first individual acquisition and a second image is obtained from the second individual acquisition. One of the two images is rotated in respect of the other image about the angle of rotation α. A correlation is determined between the one rotated image and the other image, and a point of interference is identified from the correlation.

An information processing apparatus according to an embodiment of the present disclosure includes a processing circuitry. The processing circuitry obtains a first g factor generated by using first magnetic resonance data acquired through a first parallel imaging process performed by using a plurality of reception coils and a second g factor generated by using second magnetic resonance data related to a second parallel imaging process performed by using the plurality of reception coils. The second parallel imaging process is different from the first parallel imaging process. The processing circuitry adjusts the first g factor so as to reduce a difference between the first g factor and the second g factor.

A method of operating a multi-coil magnetic resonance imaging system, is disclosed which includes establishing initial circuit values of a drive circuit, loading a tissue model associated with a tissue to be imaged, loading target values for a variable of interest (VOI) associated with operation of two or more coils of a magnetic resonance imaging system, performing a simulation based on the established circuit values and the loaded tissue model, determining output values of the VOI based on the simulation, comparing the simulated output values of the VOI to the loaded target values of the VOI, if the simulated output values are outside of a predetermined envelope about the loaded target values of the VOI, then performing a first optimization until the simulated output values are within the predetermined envelope.

Systems and methods for designing and fabricating three-dimensional objects with precisely computed material compositions for use in enhancing electromagnetic fields for magnetic resonance imaging (“MRI”) are provided. As examples, the fabricated object can be designed to reduce magnetic field inhomogeneities in the main magnetic field of an MRI system, or to reduce inhomogeneities in a transmit radio frequency (“RF”) field (i.e., a B.sub.1 field). As examples, the object can be a shim; a housing or other part of an RF coil; a medical device, such as a surgical implant; or component used in a medical device, such as a housing for an implantable medical device.

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).

The invention relates to a method of MR imaging of an object (10) placed in an examination volume of an MR apparatus (1). It is an object of the invention to enable fast 3D MR imaging that provides motion-compensation and also allows a precise compensation for system imperfections. The method of the invention comprises the steps of: —subjecting the object (10) to a number of shots (S1-S4) of a 3D imaging sequence, wherein a train of MR signals is generated by each shot (S1-S4), each MR signal representing a k-space profile, wherein the set of k-space profiles of each shot (S1-S4) comprises at least one navigator profile and a number of imaging profiles; —acquiring the MR signals; —deriving motion information from the at least one navigator profile; and —reconstructing an MR image from the imaging profiles, wherein a motion-compensation is applied based on the motion information. Motion-induced phase errors can be derived from the navigator profiles, wherein the motion-compensation involves a corresponding phase-correction. Further, phase errors caused by magnetic field gradient imperfections and/or eddy currents can be derived from the navigator profiles and a corresponding phase-correction can be applied during image reconstruction. Moreover, the invention relates to an MR apparatus (1) for carrying out this method as well as to a computer program to be run on an MR apparatus (1).

Nyquist ghost artifacts in echo planar imaging (“EPI”) are mitigated, reduced, or otherwise eliminated by implementing robust Nyquist ghost correction (“NGC”) directly from two reversed readout EPI acquisitions. As one advantage, these techniques do not require explicit reference scanning A model-based process is used for directly estimating statistically optimal NGC coefficients from multi-channel k-space data.

The present disclosure relates to a method for correcting chemical shift artifacts, CSA, which arise in the magnetic resonance DIXON method when using bipolar readout gradients (fast DIXON MR) to capture the in-phase and opposed-phase echoes.