In magnetic resonance imaging using a measurement sequence of the “free precession of transverse magnetization in the steady state”-type i.e., an SSFP measurement sequence, during the SSFP measurement sequence, the implementation of a preparation sequence takes place to reduce a signal contribution of the transverse magnetization in an outer region surrounding a measurement region in the MR imaging. The implementation of the preparation sequence includes the radiation of a multidimensional, spatially selective RF pulse that acts in a spatially selective manner on the transverse magnetization in the outer region. Saturation of the transverse magnetization and/or dephasing of the transverse magnetization in the outer region can be achieved by the multidimensional, spatially selective RF pulse.

A method for iteratively calibrating a reconstruction kernel for use in accelerated magnetic resonance imaging (MRI) is provided. An MRI system is used to acquire k-space data from multiple slice locations following the application of a multiband radio frequency (RF) excitation pulse. An initial reconstruction kernel is generated from the acquired k-space data, and this initial reconstruction kernel is used to produce an initial image for each of the multiple slice locations by applying the initial reconstruction kernel to the acquired k-space data. The average phase of each slice location is then calculated from these images, and used to shift the phase values of the subsequently acquired k-space data. From the phase-shifted k-space data, an updated reconstruction kernel is then generated. This process is repeated iteratively until a stopping criterion is satisfied.

An apparatus and method which produce a magnetic field gradient by physically rotating one or more permanent magnets near an object in order to obtain images of the object.

In a method for an accelerated progression of a repeating pulse sequence with an optimized gradient curve (that has at least one pulse) for a magnetic resonance examination by operation of a magnetic resonance apparatus, boundary conditions for a first gradient pulse of a first progression of the pulse sequence are detected, and the boundary conditions of the first gradient pulse of the first progression of the pulse sequence are compared with boundary conditions of a previous gradient pulse of a previous progression of the pulse sequence. An optimized gradient curve of the first gradient pulse of the first progression of the pulse sequence is determined from the gradient curve of the previous gradient pulse when agreement of the boundary conditions of the first gradient pulse with the boundary conditions of the previous gradient pulse exists.

A towable transient electromagnetic survey device for connection to a land, water based or an airborne towing vehicle is provided. The towable transient electromagnetic survey device includes a central body structure and a number of booms extending therefrom to interconnect the central body structure to the towing vehicle and suspend a transmitter loop for generating a primary electromagnetic field. Receiving loop(s) and transmitter loop(s) may also be housed in the central body structure. The central body structure may also be configured for switching in and out of connection of various transmitter and receiver loop configurations. In particularly preferred arrangements, the location of a transmitter loop or a pair of transmitter loops relative to a receiver loop is effective for substantially nulling mutual inductance between the transmitter loop(s) and the receiver loop.

A wireless sensor platform and methods of manufacture are provided. The platform involves providing a plurality of wireless sensors, where each of the sensors is fabricated on flexible substrates using printing techniques and low temperature curing. Each of the sensors can include planar sensor elements and planar antennas defined using the printing and curing. Further, each of the sensors can include a communications system configured to encode the data from the sensors into a spread spectrum code sequence that is transmitted to a central computer(s) for use in monitoring an area associated with the sensors.

A method for operating a magnetic resonance imaging (MRI) system that includes: accessing data indicating a first region for imaging a portion of a subject, the portion being placed in a main magnet of the MRI system and the main magnet generating a magnetic field; selecting, from a group of available shimming coils, a first subset of shimming coils arranged and configured such that, when the shimming coils in the first subset are driven, a homogeneity of the magnetic field at the first region is increased; and driving the shimming coils in the selected first subset of shimming coils without driving other shimming coils in the group of available shimming coils such that the homogeneity of the magnetic field at the first region increases relative to the homogeneity of the magnetic field at the first region when the shimming coils of the selected first subset are not driven.

A radio frequency (RF) coil assembly for use in magnetic resonance includes a radio frequency coil (42, 100) and an electronic switch (28) which switches between open and closed states to detune and tune the coil to a preselected resonance frequency. Each electronic switch includes at least one field effect transistor (FET) (70) and a bias network (72).

In a method for controlling a magnetic resonance tomography system for a Magnetic Resonance Fingerprinting (MRF) measurement: a dictionary group including at least two dictionaries is provided/created, each of the at least two dictionaries containing a multiplicity of different intensity profiles with a specific sampling scheme; a preliminary recording of magnetic resonance tomography (MRT) measurements is created; a sampling scheme is determined/defined based on the preliminary recording; a dictionary is selected from the at least two dictionaries of the dictionary group based on the preliminary recording; and an MRF measurement is performed using the defined sampling scheme and an MRF evaluation based on the selected dictionary.

A magnetic resonance imaging apparatus includes a magnetic assembly including a main magnet and a gradient coil unit and forming a static magnetic field and a gradient magnetic field in the bore thereof, and a gradient controller applying a test gradient waveform to the magnetic assembly, and compensating for a distortion of the magnetic field gradients, caused by eddy currents, by reflecting the actual shape of the applied test gradient waveform.