Abstract: A method for generating a desired temporal profile of the magnetization state in an object under examination (O) during an experiment involving magnetic resonance is characterized in that at least one spatially dependent change in the magnetization state inside the object under examination (O) is predefined and spatially selective radio-frequency pulses, which allow a simultaneous and independent change in the magnetization state at locations with different stipulations, are irradiated in order to implement the predefined spatially dependent change in the magnetization state. The method permits establishment of the same desired temporal profile of the magnetization state for different regions of the object under examination despite different given experimental parameters or deliberate generation of different desired profiles of the magnetization state at different locations.

Abstract: A method for designing the time dependence function km(t) for a given k-space trajectory km, where m stands for one or multiple of the spatial dimension indices x, y, or z, of a magnetic resonance imaging (=MRI) experiment carried out on an MRI system, wherein the trajectory km is generated by applying a time varying waveform gm(t) of a gradient magnetic field, the method taking into account—the gradient magnitude limit G and—the gradient slew rate limit S of the MRI system, is characterized in that the method further takes into account a given frequency limit F in such a way that the gradient waveform gm(t) does not contain frequency components above the frequency limit F which is characteristic for the gradient hardware of the MRI system. The invention provides a method for designing a time dependence function for a given k-space trajectory, which allows obtaining better quality MRI images.

Abstract: A method for obtaining amplitude and phase dependencies of radio frequency pulses, which are irradiated within the scope of a main magnetic resonance experiment for generating a predetermined n-dimensional spatial distribution (n>=1) of transverse magnetization in an object by means of at least one radio frequency transmitting antenna of a magnetic resonance measuring system in combination with spatially and temporally varying additional magnetic fields which are superimposed on the static and homogeneous base field of the magnetic resonance measuring system and change the transverse magnetization phase in the object in dependence on location and time is characterized in that, prior to performance of the main experiment, a preparational measurement is performed in which the change with time of the transverse magnetization phase in the object under the action of the additional magnetic fields is measured in a position-resolved fashion and the amplitude and phase dependencies of the radio frequency pulses fo

Abstract: A method for position dependent change in the magnetization in an object, according to a requirement in a magnetic resonance measurement, wherein radio-frequency pulses are irradiated in conjunction with supplementary magnetic fields that vary in space and over time and are superposed on the static and homogeneous basic field of a magnetic resonance measurement apparatus along a z-direction, is characterized in that non-linear supplementary magnetic fields are used, whose spatial gradient of the z-component is not constant at least at one instant of the irradiation, and that the radio-frequency pulses to be irradiated are calculated in advance, wherein progressions over time of the field strengths of the supplementary magnetic fields in the region of the object that are calculated and/or measured position-dependently are included in this calculation.

Abstract: A method for magnetic resonance spectroscopy (=MRS) or magnetic resonance imaging (=MRI) in which an NMR time-domain signal is generated by an excited transverse nuclear magnetization precessing about the applied magnetic field, whereby the RF excitation pulse is adapted to cover a whole range of NMR frequencies of interest present in the object, and time-domain signal acquisition takes place during, or during and after the application of the RF excitation pulse, is characterized in that spectral or image data are reconstructed by a matrix product of a reconstruction matrix and a vector of time-domain signal points, the reconstruction matrix being an inversion of an encoding matrix. An improved method for reconstructing spectral or image data from a time-domain signal is thereby provided which is more versatile than conventional Fourier transform.

Abstract: A method for determining the spatial distribution of the magnitude of the radio frequency transmission field B1 in a magnetic resonance imaging apparatus, wherein the method comprises performing an MRI experiment in which a B1-sensitive complex image (SI) of a sample is obtained, wherein the phase distribution within the B1-sensitive complex image (SI) depends on the spatial distribution of the magnitude of the field B1. For establishing the dependency of the phase distribution within the B1-sensitive complex image (SI) on the spatial distribution of the field B1, one or more adiabatic RF pulses are applied. The method provides a simple procedure for mapping the B1 field of a magnetic resonance imaging apparatus with an improved accuracy and a wider measurement range.

Abstract: A method for determining the spatial distribution of magnetic resonance signals from an imaging area, wherein nuclear spins are excited in a spatially encoded fashion through multi-dimensional RF pulses, is characterized in that in a definition step, a resolution grid with resolution grid cells is predetermined, and in accordance with a predetermined phase encoding scheme, an excitation pattern is defined for each phase encoding step, in which the amplitudes within the imaging area are set in accordance with a predetermined distribution identically for each phase encoding step. In a preparatory step, the amplitude and phase behavior of the RF pulses to be irradiated is calculated in accordance with a predetermined k-space trajectory for each defined complex excitation pattern.

Abstract: A method for designing the time dependence function km(t) for a given k-space trajectory km, where m stands for one or multiple of the spatial dimension indices x, y, or z, of a magnetic resonance imaging (=MRI) experiment carried out on an MRI system, wherein the trajectory km is generated by applying a time varying waveform gm(t) of a gradient magnetic field, the method taking into account—the gradient magnitude limit G and—the gradient slew rate limit S of the MRI system, is characterized in that the method further takes into account a given frequency limit F in such a way that the gradient waveform gm(t) does not contain frequency components above the frequency limit F which is characteristic for the gradient hardware of the MRI system. The invention provides a method for designing a time dependence function for a given k-space trajectory, which allows obtaining better quality MRI images.

Abstract: A method for generating magnetic resonance (MR) images or MR spectra of at least one partial area (2a) of a moving object (2) with at least one motion sequence that is repeated during consecutive motion states (BZ) is proposed. In a learning measurement, a monitor signal of the repeating motion sequence is recorded, and MR test data of the partial area (2a) of the object (2) are recorded under known measurement conditions, wherein the MR test data is associated with the motion states (BZ) of the motion sequence. In an evaluation step, the MR test data of the motion states (BZ) of the motion sequence are compared to each other with respect to at least one parameter, and the variation of the at least one parameter over the motion sequence is determined.

Abstract: A method for determining amplitude and phase dependencies of radio frequency pulses that are irradiated during traversal of a defined k-space trajectory to produce a spatial pattern of the transverse magnetization in an MR experiment using at least one RF transmission antenna, is characterized in that, in a calibration step, a set of basic pulses is defined, each basic pulse is irradiated individually, the specified k-space trajectory is traversed and at least one set of basic patterns is produced by detection of the MR signals thus excited, which in a range to be examined of the object, are proportional to the complex transverse magnetization produced, wherein the k-space trajectory is traversed fully identically every time at least from the beginning of the irradiation of each basic pulse, and, in a calculation step, a defined target pattern is approximated with a linear combination of the basic patterns of a set or with a mathematical association of linear combinations, with which, within each set, the bas

Abstract: A method for determining the spatial distribution of magnetic resonance (MR) signals from an imaging region has a preparatory step in which an encoding scheme with I phase encoding steps is defined, for each phase encoding step according to the phase encoding scheme, an excitation pattern of the transverse magnetization is defined and RF pulses to be irradiated to implement this pattern are calculated, wherein the same phase is defined at all spatial locations of the imaging region within an MSEM region and, in the execution step, according to the spatial encoding scheme each encoding step is performed I times according to the phase encoding scheme, wherein selection of the imaging region, amplitude modulation, and phase encoding are performed with the calculated RF pulses during excitation of the nuclear spin. This results in unique determination of the spatial distribution of the magnetic resonance signals with a simple RF receiver configuration using local gradient systems.

Abstract: A method for generating MR (magnetic resonance) images of a moving partial area of an object with a repeating motion sequence over comparable motion states, wherein an MR data set, which is encoded for generating an individual MR image of the object, is provided for each motion state from a plurality of successive individual MR measurements with shorter time intervals than a repetition rate of the motion sequence, and wherein at least one navigator data point is generated for each individual MR measurement as an indicator for the comparability of several motion states, is characterized in that a position of the partial area is determined for each individual MR image, from which a function f(t) of the time shift of the position is determined, and the measuring data of the individual MR measurement is phase-corrected in correspondence with its respective motion state using the function f(t) to keep the position of the partial area in a spatially stationary state.

Abstract: A method for obtaining amplitude and phase dependencies of radio frequency pulses, which are irradiated within the scope of a main magnetic resonance experiment for generating a predetermined n-dimensional spatial distribution (n>=1) of transverse magnetization in an object by means of at least one radio frequency transmitting antenna of a magnetic resonance measuring system in combination with spatially and temporally varying additional magnetic fields which are superimposed on the static and homogeneous base field of the magnetic resonance measuring system and change the transverse magnetization phase in the object in dependence on location and time is characterized in that, prior to performance of the main experiment, a preparational measurement is performed in which the change with time of the transverse magnetization phase in the object under the action of the additional magnetic fields is measured in a position-resolved fashion and the amplitude and phase dependencies of the radio frequency pulses fo

Abstract: A method for magnetic resonance spectroscopy (=MRS) or magnetic resonance imaging (=MRI) in which an NMR time-domain signal is created by an RF excitation pulse applied to an object in the presence of an applied magnetic field that may depend on spatial position and/or time, the time-domain signal being generated by an excited transverse nuclear magnetisation precessing about the applied magnetic field, whereby the RF excitation pulse is adapted to cover a whole range of NMR frequencies of interest present in the object, and time-domain signal acquisition takes place during, or during and after the application of the RF excitation pulse, is characterized in that spectral or image data are reconstructed by a matrix product of a reconstruction matrix and a vector of time-domain signal points, the reconstruction matrix being an inversion of an encoding matrix An? whose elements are calculated using the formula: A n ? ? ? = ? m = 0 n - 1 ? ? P m ? ? ?? ? ( n , m , ? ) , whe

Abstract: A method for determining the spatial distribution of the magnitude of the radio frequency transmission field B1 in a magnetic resonance imaging apparatus, wherein the method comprises performing an MRI experiment in which a B1-sensitive complex image (SI) of a sample is obtained, wherein the phase distribution within the B1-sensitive complex image (SI) depends on the spatial distribution of the magnitude of the field B1. For establishing the dependency of the phase distribution within the B1-sensitive complex image (SI) on the spatial distribution of the field B1, one or more adiabatic RF pulses are applied. The method provides a simple procedure for mapping the B1 field of a magnetic resonance imaging apparatus with an improved accuracy and a wider measurement range.

Abstract: An installation for investigating objects (10a) using magnetic resonance comprising a safety room (1) which has gastight walls (1a-c) and having a magnet system (9) for producing a homogenous magnetic field in an investigational volume (13), the magnet system (9) comprising a gastight outer shell (19) which is penetrated in a shell region (29) by feed-throughs (39a-d) into the interior of the magnet system (9), is characterized in that the magnet system (9) is arranged in the safety room (1), and one of the gastight walls (1a-c) is penetrated in an access region (1e), wherein a gastight connecting element (14) is present between the access region (1e) and the shell region (29) which, at its ends, is connected in a gastight manner to the gastight wall and the gastight outer shell (19) respectively, so that access from outside the safety room (1) is available to the shell region (29) and the feed-throughs there (39a-d), that access being sealed in a gastight manner with respect to the safety room (1).

Abstract: A method for generating MR (magnetic resonance) images of a moving object with a repeating motion pattern at comparable motion states, wherein for at least one motion state, a set of MR data which is completely encoded for producing an MR image is provided from a plurality of successive individual MR measurements. The method is characterized in that at least one contiguous region of successive data points is used as indicator within the individual MR measurement, wherein this contiguous region is identically repeated for all individual MR measurements within the respective MR measuring sequence relative to irradiated RF (radio frequency) pulses and switched gradients. This provides reliable allocation of the recorded MR data with the associated motion states, wherein completely encoded sets of MR data can be determined within an optimum time.

Abstract: A method for determining the spatial distribution of magnetic resonance (MR) signals from an imaging region within MSEM regions of a local gradient system, wherein, in a preparatory step, a spatial encoding scheme is defined; in an execution step, nuclear spins are repeatedly excited with RF pulses, and thereafter spatially encoded according to the spatial encoding scheme, in at least one dimension by means of the local gradient system, and MR signals are acquired, from which the spatial distribution is calculated, visualized and/or stored, characterized in that in the preparatory step, a phase encoding scheme with I phase encoding steps is defined, for each phase encoding step according to the phase encoding scheme, an excitation pattern of the transverse magnetization is defined and RF pulses to be irradiated to implement this pattern are calculated, wherein the same phase is defined at all spatial locations of the imaging region within a MSEM region and, in the execution step, according to the spatial enc

Abstract: An MRI configuration comprising an MRI phantom positioned in a volume under investigation, wherein the MRI phantom has a chamber disposed in a housing and filled with a liquid, in which a gas bubble forms, the liquid nuclei which have an NMR relaxation time T1 of between 100 ms and 20 s, is characterized in that the chamber the MRI phantom a main chamber and a partial chamber, the main chamber being delimited from the partial chamber such that the gas bubble can completely enter the partial chamber due to its buoyancy by changing the spatial orientation of the MRI phantom in the gravitation field, and remains in the partial chamber in a measurement orientation of the MRI phantom due to its buoyancy. This eliminates imaging artefacts despite the presence of a gas bubble.

Abstract: An NMR probe head for investigating a temperature-sensitive test object in a volume under investigation with at least one RF receiver coil which is cooled to cryogenic temperatures during operation, and is surrounded by a housing, wherein at least one heatable separating wall is provided between the RF receiver coil and the test object, is characterized in that the separating wall is produced from a material having excellent heat conducting properties, wherein the separating wall is coupled in a heat conducting fashion to at least one heating element at a separation from the volume under investigation via at least one contact location. The inventive NMR probe head permits disposition of the RF receiver coil in close proximity to the test object to be measured without inadvertently cooling it.