A method of preparing a multi-channel coil, in particular for magnetic resonance imaging (MRI) or for a medical treatment device, wherein the multi-channel coil comprises at least two coil rows being axially arranged along a longitudinal direction (z), wherein each of the at least two coil rows comprises a plurality of coil elements being azimuthally distributed relative to the longitudinal direction (z), comprises the steps of a) electro-magnetic decoupling of the coil rows relative to each other, and b) minimizing a reflected power (P.sub.ref.sub._.sub.row) individually of each of the coil rows. Furthermore, a method of operating a multi-channel coil, in particular for magnetic resonance imaging (MRI) or for a medical treatment device, and a multi-channel coil, which is prepared using to the above method are described.

A magnetic resonance imaging apparatus includes an imaging unit configured to carry out magnetic resonance imaging of a patient using a transmitting QD coil that allows at least one of phase and amplitude of a radio-frequency transmit pulse on at least one input channel of the transmitting QD coil to be adjusted independently of each other, and an adjustment unit arranged to adjust at least one of the phase and the amplitude of the radio-frequency transmit pulse according to imaging conditions.

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 computer-implemented method is disclosed for providing an actuation sequence which specifies transmit signals for at least one high-frequency transmit channel of an antenna arrangement of a magnetic resonance device for acquiring measurement data of an object under investigation by the magnetic resonance device. The method includes providing different actuation sequences, wherein each sequence is the result of an optimization method and which differs with regard to the value of an optimization parameter taken into account in the course of the optimization method. The method further includes providing a plurality of field distribution maps, (e.g., at least one B.sub.0 map and/or at least one B.sub.1 map), acquired by the or a further magnetic resonance device from the object under investigation. The method further includes selecting the actuation sequence to be used from the different actuation sequences depending on the field distribution maps and providing the actuation sequence to be used.

A method is provided for calibration of a magnetic resonance device with a transmitting device for generating an excitation field. In a first acquisition phase, a first transmitting coil element is detuned, at least one second transmitting coil element is tuned, and an MR data set is acquired using the transmitting device. In a second acquisition phase, the first transmitting coil element, the at least one second transmitting coil element are tuned, and at least one further MR data set is acquired using the transmitting device. By an arithmetic unit, a calibration factor is determined based on the MR data set and the at least one further MR data set for calculating a total voltage value at a feeding point of the first transmitting coil element from voltage values, which may be measured at a measuring point of an electrical supply line of the first transmitting coil element.

Systems and methods for magnetic resonance imaging, including adjusting spatial distribution of a rotating magnetic field. By minimizing imaging time, the B.sub.1 nonuniformity reducing effect of RF shimming is maximized for an imaging section of an arbitrary axis direction and an arbitrary position. B.sub.1 distributions are measured for only several sections of one predetermined direction, and a radio frequency magnetic field condition that maximizes the B.sub.1 non-uniformity reducing effect for an imaging section of an arbitrary direction and an arbitrary position is calculated from the B.sub.1 distribution data.

Nuclear spins are excited in a region of interest in an object under examination by a radio-frequency pulse. During at least one phase of the radio-frequency pulse, excitation fields are transmitted while magnetic field gradients are simultaneously applied so that the magnetization of the nuclear spins moves on a trajectory through a transmission k-space. In a first phase of the at least one phase of the radio-frequency pulse, the trajectory moves at a radial distance around the center of the transmission k-space. The radial distance corresponds to the radius of a sphere superimposed with at least one radial harmonic.

Accelerated data acquisition using two-dimensional (“2D”) radio frequency (“RF”) pulse segments as virtual receivers for a parallel image reconstruction technique, such as GRAPPA, is provided. Data acquisition is accelerated using segmented RF pulses for excitation, refocusing, or both, and undersampling k-space along a dimension of the RF pulse segments. In this way, parallel image reconstruction techniques, such as GRAPPA, can be adapted to work with a single RF receive coil. By undersampling the data acquisition and finding correlations between the data from different segments, unsampled data can be recovered. This shortens scan times, yielding the advantages of segmented pulses without the formerly required long scans.

Systems and methods are provided for acquiring imaging data from one or more resonance species that simultaneously produce individual magnetic resonance signals in a plurality of different slices. The data is acquired by simultaneously exciting, using a pTX RF coil array, a plurality of different slices such that at least some of the plurality of different slices are excited by transmitting RF energy from a subset of transmit channels in the pTX RF coil array. The method also includes comparing the data to a dictionary of signal evolutions to determine quantitative values for two or more parameters of the resonant species based, at least in part, on matching the data to a set of known signal evolutions stored in the dictionary. The method includes producing an image for each of the plurality of different slice locations, at least in part, on the quantitative values.

In a method for detecting MR signals of an object in an MR scanner, in which the MR signals of the object are detected with receiving channels at the same time using a parallel imaging technique, where the MR signals are spin-echoes generated with a spin-echo based imaging sequence, a first magnetic field gradient (MFG) is applied in a slice selection direction (SSD) while applying an RF excitation pulse of the spin echo based imaging sequence, the first MFG having a first polarity during the application of the RF excitation pulse, a second MFG is applied in the SSD while applying at least a first RF refocusing pulse of the spin echo based imaging sequence, the second magnetic field gradient has a second polarity opposite to the first polarity, and the MR signals of the spin echo are detected to generate an MR image based on the detected MR signals.