A monitoring method and device for a magnetic resonance imaging system comprises: acquiring a whole body specific absorption rate of a subject under examination; acquiring a ratio between a local region specific absorption rate and the whole body specific absorption rate of the subject under examination on the basis of current parameter information of a local coupling coil in the magnetic resonance imaging system; and calculating the local region specific absorption rate of the subject under examination on the basis of the ratio between the local region specific absorption rate and the whole body specific absorption rate, and the whole body specific absorption rate.

A method and apparatus for determining spatial distribution of a complex radio frequency (RF) of both transmit field and receive sensitivity a magnetic resonance imaging (MRI) system. The method includes estimation of the absolute phase of transmit field using a reference transmit coil or array coils with minimal absolute phase. The method and apparatus include estimation of complex receive sensitivity of a transceiver coil using the complex transmit field of the transceiver coil or array coils.

The invention provides for a magnetic resonance imaging system (100, 300, 100) for acquiring magnetic resonance data (110, 1104) from a subject (118) within an imaging zone (108). The magnetic resonance imaging system comprises a memory (136) for storing machine executable instructions (160, 162, 164, 166, 316) and pulse sequence data (140, 1102). The pulse sequence data comprises instructions for controlling the magnetic resonance imaging system to acquire magnetic resonance data according to a magnetic resonance imaging method. The magnetic resonance imaging system further comprises a processor (130) for controlling the magnetic resonance imaging system. Execution of the machine executable instructions causes the processor to: acquire (1200) the magnetic resonance data by controlling the magnetic resonance imaging system with the pulse sequence data; calculate (1202) a B0 inhomogeneity map (148) by analyzing the magnetic resonance data according to the magnetic resonance imaging method, calculate (1204) a B1 phase map (150) and/or a B1 amplitude map (1106) by analyzing the magnetic resonance data according to the magnetic resonance imaging method; and calculate (1206) a second derivative (1110) of the B1 phase map and/or a second derivative of the B1 magnitude map 1 and/or a second derivative of the B0 in homogeneity map in at least one predetermined direction. The second derivative is calculated using a corrected voxel size in the at least one predetermined direction, wherein the corrected voxel size is calculated using a correction factor calculated from the derivative of the B0 inhomogeneity map.

In order to improve B1 non-homogeneity while reducing a local SAR in an object, particularly, in a human tissue during MR imaging, the present invention is characterized in that each of a plurality of irradiation channels is controlled on the basis of RF shimming parameters corresponding to the plurality of irradiation channels, and, in a case of performing imaging sequence of irradiating an object with an RF magnetic field, there is the use of the RF shimming parameters obtained by imposing a constraint condition on at least one of a plurality of principal components obtained through principal component analysis on the RF shimming parameters.

Embodiments now disclosed herein provide an apparatus and method in which free radicals can be detected in a substance by MRI without changing the MRI static field.

According to one embodiment, a magnetic resonance imaging apparatus includes processing circuitry. The processing circuitry acquires an ambient temperature relating to a magnetic resonance imaging examination and determines an interlock value of a specific absorption rate (SAR) in accordance with the ambient temperature.

The present disclosure is directed to a device and a magnetic resonance system for concentrating a magnetic field of radio frequency signals, and methods for concentrating a magnetic field of as radio frequency signal in an object to be imaged.

In some examples, a method including detecting, via processing circuitry, an induced voltage in at least one of an electrode or a lead conductor of an implantable medical device, wherein the induced voltage is induced in the at least one of the electrode or the lead conductor of the implantable medical device by a radio frequency (RF) field generated by a magnetic resonance imaging (MRI) scanner; and modifying, via the processing circuitry, an MRI scan based on the detected induced voltage.

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.

An MRI system coil insert 2 for use within a bore B of a main MRI system 1, the coil insert 2 comprising at least one gradient coil, for creating a spatially varying magnetic field along a respective axis and being arranged to be electrically driven at an ultrasonic frequency.