Technologies applicable to NMR spin-echo amplitude estimation are disclosed. Example methods may calibrate for distortion of a shape and estimated amplitude of measured NMR spin or gradient echoes. NMR spin or gradient echo measurements may be performed on a sample. The measured NMR spin or gradient echoes may be used to calculate an echo-shape calibration factor. The echo-shape calibration factor may estimate an effect of echo shape on estimated spin or gradient echo amplitude(s) of the NMR spin or gradient echoes. The echo-shape calibration factor may be used to correct for underestimation or overestimation of the spin or gradient echo amplitude(s).

A magnetic resonance CEST imaging sequence and device based on a frequency stabilization module are provided. It includes following steps: first, in the frequency stabilization module, exciting a target slice with a small-flip-angle radio frequency pulse, and collecting three lines of non-phase-encoded k-space data; second, obtaining an estimated value of the frequency drift of the main magnetic field by calculating the phase difference between the three lines of non-phase encoded k-space data; third, adjusting a center frequency of the radio frequency pulse based on the calculation result of the frequency drift of the main magnetic field, to realize a real-time correction of the frequency drift of the main magnetic field; and fourth, performing conventional magnetic resonance CEST imaging.

According to one embodiment, a magnetic resonance imaging apparatus includes processing circuitry. The processing circuitry calculates power of a first RF magnetic field required for excitation at a first flip angle in a first target slice, acquires information on inhomogeneity of a transmission RF magnetic field for a cross section crossing the first target slice, and calculate power of a second RF magnetic field required for excitation at a second flip angle in a second target slice different from the first target slice for the cross section by using the information and the first RF magnetic field power.

A device and system for generating a broadband excitation signal and corresponding excitation field to a substance under test in an NMR system is presented. The excitation signal is generated, according to a broadband transmitter, to a coil in the NMR system. A corresponding broadband receiver is also presented that acquires a response signal resulting from a response field emanating from the substance under test. Neither the transmitter nor the receiver require that the frequency of operation be determined according to a particular configuration of electrical devices to determine a resonance characteristic that tunes to a particular operational frequency. Rather, the operational frequency is determined according to control and driver devices triggered according to command and control signals in the case of the transmitter, and according to reactive elements, that are not configured as a tuned circuit, in the case of the receiver.

The present invention relates to an RF transmit system and method, MRI system and a pre-scan method and medium thereof. The RF transmit system comprises: an RF output unit, for generating and outputting an RF pulse signal; an RF amplifier, for amplifying the RF pulse signal; and a signal processing unit, for communicating the amplified RF pulse signal to an RF transmit coil of the MRI system and outputting a feedback signal to the RF output unit, wherein the RF output unit generates a linearity compensation control signal based on the feedback signal and a predetermined feedback signal-linearity compensation value-relationship, so as to carry out linearity compensation for the RF pulse signal outputted by the RF output unit. The RF transmit method corresponds to the above noted system and the MRI system comprises the above noted RF transmit system. The pre-scan method comprises the RF transmit method. Instructions recorded by the medium may execute the above noted RF transmit method and pre-scan method.

In a method and apparatus for generating a magnetic resonance (MR) image data set of a target region, MR data for a first number of slices are recorded and the recording of MR data for a second number, which is smaller than or equal to the first number, of different slices takes place simultaneously. A separation algorithm of the parallel imaging is used to determine MR data that are assigned to individual slices from the multi-slice data set produced during the simultaneous recording of the multiple slices. This separation algorithm uses input parameters determined from a calibration data set of the target region, the calibration data set being recorded in a reference scan, after which the MR image data set is reconstructed from the MR data assigned to individual slices, wherein at least part of the calibration data set is also used for reconstructing the MR image data set.

According to one embodiment, a magnetic resonance imaging apparatus includes an amplifier, a capacitor bank, and processing circuitry. The amplifier supplies, based on an imaging sequence, an RF pulse to an RF coil which generates a radio frequency magnetic field. The capacitor bank supplies an electric power to the amplifier. The processing circuitry judges whether an imaging by the imaging sequence is able to be executed, based on a condition of the RF pulse in the imaging sequence and an output efficiency of the amplifier.

Methods for correcting a non-uniform power response of a radiofrequency (“RF”) transmit coil used in magnetic resonance imaging (“MRI”) are described. Transmit power response data for an RF transmit coil are processed to compute RF amplitude scaling factors for the RF transmit coil as a function of transmit frequency offset. The RF amplitude scaling factors can be used to correct transmitted RF power, and thus flip angle, to be more uniform over a range of transmit frequency offsets, as may be encountered when imaging with lower field MRI systems or MRI systems with high strength or asymmetric gradients.

An MRI scanner and a method for operation of the MRI scanner are provided. The MRI scanner has a first receiving antenna for receiving a magnetic resonance signal from a patient in a patient tunnel, a second receiving antenna for receiving a signal having the Larmor frequency of the magnetic resonance signal, and a receiver. The second receiving antenna is located outside of the patient tunnel or near an opening thereof. The receiver has a signal connection to the first receiving antenna and the second receiving antenna and is configured to suppress an interference signal by the second receiving antenna in the magnetic resonance signal received by the first receiving antenna.

The present disclosure discloses a magnetic resonance CEST imaging sequence and device based on a frequency stabilization module. It includes following steps: first, in the frequency stabilization module, exciting a target slice with a small-flip-angle radio frequency pulse, and collecting three lines of non-phase-encoded k-space data; second, obtaining a fine estimated value of a frequency drift of a main magnetic field by calculating a phase difference between the first and second lines of non-phase encoded k-space data; then obtaining a coarse estimated value of the frequency drift of the main magnetic field by calculating a difference between a phase difference between the second and third lines and the phase difference between the first and second lines; then determining the value of the frequency drift of the main magnetic field by comparing a difference between the coarse estimated value and the fine estimated value with a threshold; then adjusting a center frequency of the radio frequency pulse based on the calculation result of the frequency drift of the main magnetic field, to realize a real-time correction of the frequency drift of the main magnetic field; and finally, performing conventional magnetic resonance CEST imaging. The present disclosure realizes the real-time correction of the frequency drift of the main magnetic field during magnetic resonance CEST imaging and ensures effective suppression on fat signals, thereby improving magnetic resonance CEST imaging performance.