Movement detection of at least one part of a subject located inside a magnetic resonance imaging (MRI) device is provided. A method includes performing an MR scan by executing a programmable MR sequence protocol. The sequence protocol includes MR excitation pulses to be transmitted via a parallel transmit system and receive time windows for receiving magnetic resonance signals via a receive system. The MR sequence protocol includes, in between the MR excitation pulses, the generation of multi-channel pilot tone signals that are transmitted via the parallel transmit system and an RF transmit coil array. During transmission of the multi-channel pilot tone signals, the pilot tone signals are received with an RF receive coil array. The received pilot tone signals are forwarded via the receive system to an analyzing unit, and movement of at least one part of the subject is determined by analyzing the received pilot tone signal.

A method of operating a magnetic resonance scanner includes determining a radio frequency (RF) pulse to be transmitted to jointly homogenize a flip angle and a semisolid saturation that would result from magnetization of a sample to be scanned by the MR scanner using the determined RF pulse. The method also includes controlling an RF transmit coil of the MR scanner to transmit the determined pulse. Homogenizing both semisolid saturation and excitation properties of the RF pulse allows for improved magnetic transfer ratio imaging.

In one embodiment, a biological information monitoring apparatus includes: an antenna assembly including at least one antenna, the antenna assembly being configured to be disposed close to an abject; a signal generator configured to generate a high-frequency signal; a coupling-amount detection circuit configured to detect coupling amount of near-field coupling due to an electric field between the object and the at least one antenna by using the high-frequency signal; and a displacement detection circuit configured to detect a physical displacement of the object based on change in the coupling amount of near-field coupling.

A pulse-design unit for creating pulse data for controlling a magnetic resonance system includes a data interface configured for receiving an examination scheme, and a calculation module configured for generating pulse data based on an examination scheme. The pulse-design unit includes a data grid and/or parameter values created from map pairs of a plurality of patients and is configured to select and/or calculate pulse data using the data grid and/or parameter values and a provided examination scheme. A method and a control device for controlling a magnetic resonance imaging (MRI) system and a related magnetic resonance imaging system are also provided.

The invention relates to a method for optimization of a performance of a multi-channel transmitter including several transmit elements, particularly in a magnetic resonance imaging device. The method includes: (a) Exciting the transmit elements of the multi-channel transmitter by electric excitation signals comprising a specific power, with the power of the excitation signals partially reflected by the transmit elements of the multichannel transmitter, (b) Determining a reflected power which is reflected by the multi-channel transmitter during excitation of the transmit elements, (c) Determining reflection coefficients S.sub.xx of the multi-channel transmitter, (d) Determining reflection coefficients S.sub.xy of the multi-channel transmitter, (e) Calculating a performance criterion representing the performance of the multi-channel transmitter, with the performance criterion based on the reflected power, the reflection coefficients S.sub.xx and the reflection coefficients S.sub.xy, and (f) Tuning the multi-channel transmitter so that the performance criterion is optimized.

The present invention provides a method and apparatus for generating a specific flip angle distribution in magnetic resonance imaging; the method uses a plurality of RF transmission coils combined with linear and nonlinear spatial encoding magnetic fields to generate a homogeneous flip angle distribution.

Method and apparatus for hardware coil compression is disclosed. The coils in an array configured for the same region of interest are grouped into sub-arrays. The coils of each sub-array are pre-combined with a hardware combiner before further processing. The pre-combination converter composed of the pre-combiners is flexible, i.e., applicable to for example non-cylindrical coils; simpler than direct implementation of the software compression algorithm; and commercially feasible.

A method of designing a pulse sequence for parallel-transmission MRI includes a) for each one of a plurality of subjects, estimating a linear adjustment transformation (L), converting amplitude maps of RF fields generated by respective transmit channels of a MRI apparatus into respective standardized maps; and b) determining RF waveforms (P) minimizing a discrepancy between subject-specific distributions of flip-angles of nuclear spin and a target distribution, averaged over said subjects, the subject-specific distributions corresponding to the flip-angle distributions achieved by applying a superposition of RF fields, each having a temporal profile described by one of said RF waveforms and a spatial amplitude distribution described by a respective standardized map determined for the subject. A method and an apparatus for performing parallel-transmission MRI using such a pulse sequence are provided.

Systems and methods for designing RF pulses using a technique that directly controls temperature rise via a compression model that is based on virtual observation points (“VOPs”) are provided. Thermal pre-simulations are first carried out for a given RF exposure time, coil, and subject model in order to obtain complex temperature matrices, after which the compression scheme follows. As one example, the thermal model employed can be Pennes' bio-heat equation. Focusing design constraints on the temperature rise instead of the absolute temperature allows for uncertain parameters to be dropped from the thermal model, making it more robust and less prone to errors. In some embodiments, the algorithm used for RF pulse design is the active-set (“A-S”) method.

A computer-implemented method of visualizing blood flow through a patient using magnetic resonance imaging (MRI) includes receiving an image of the portal venous system of the patient's liver at a full field of view. A reduced field of view is defined which encompasses the portal venous system of the patient's liver and excludes extraneous anatomy in the full field of view. A navigator area is defined in the full field of view and outside of the reduced field of view. Transmit channels are used to selectively excite the reduced field of view and the navigator area throughout a cardiac cycle of the patient. Measurement data is acquired in response to the selective excitation. The acquired data is used to generate time-resolved 3D datasets. Additionally, a 3D visualization of blood flow though the portal venous system is generated based on the time-resolved 3D datasets.