Abstract: In a method (100 to 208) in which hyperpolarizable tracer molecules (20, 88 to 98) are hydrogenated and then optionally also hyperpolarized for magnetic resonance imaging, it is provided that, in a first method step (104, 202), a hydrogen solution (10, 12, 4) having a saturation factor of at least 50% be prepared and that the hydrogenation reaction (186 to 190, 206) not be triggered until a subsequent, second method step (106, 204). An apparatus (1) with which the method of the invention (100 to 208) is executable is also provided.

Abstract: Improvements in MR spiral imaging are provided in that spiral segments (2 to 8) are reordered, in particular alternately traversed and/or permuted. Moreover, repeatedly approaching the same post-trajectory points (16) between the acquisitions of the spiral segments (2 to 8) is provided, in which the post-trajectory points (16) are located outside of the center (18) of k-space (9), preferably outside of a region (20) of the k-space (9) covered by the spiral segments (2 to 8).

Abstract: In a method (100 to 208) in which hyperpolarizable tracer molecules (20, 88 to 98) are hydrogenated and then optionally also hyperpolarized for magnetic resonance imaging, it is provided that, in a first method step (104, 202), a hydrogen solution (10, 12, 4) having a saturation factor of at least 50% be prepared and that the hydrogenation reaction (186 to 190, 206) not be triggered until a subsequent, second method step (106, 204). An apparatus (1) with which the method of the invention (100 to 208) is executable is also provided.

Abstract: Improvements in MR spiral imaging are provided in that spiral segments (2 to 8) are reordered, in particular alternately traversed and/or permuted. Moreover, repeatedly approaching the same post-trajectory points (16) between the acquisitions of the spiral segments (2 to 8) is provided, in which the post-trajectory points (16) are located outside of the center (18) of k-space (9), preferably outside of a region (20) of the k-space (9) covered by the spiral segments (2 to 8).

Abstract: A method to compensate for the magnetic field heterogeneity inside an object of investigation in a MR device obtains an uncorrected magnetic field distribution of the object and executes an MR sequence with a desired k-space coverage by applying RF pulses to generate a transverse magnetization within the object. MR signal data is recorded, magnetic field shimming parameters are dynamically updated and MR signal data are reconstructed to produce images or localized spectroscopic data. Artifacts in a reconstructed image resulting from an uncorrected magnetic field distribution are suppressed by temporally separating MR signals originating from at least two different sub-volumes within a volume of transverse magnetization by generating a nonlinear phase distribution within the object and by dynamically updating shimming parameters to compensate for the field inhomogeneity distributions within the different sub-volumes in the volume of transverse magnetization.

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 magnetic resonance method for using radio frequency pulses for spatially selective and frequency selective or multidimensionally spatially selective excitation of an ensemble of nuclear spins with an initial distribution of magnetization in a main magnetic field aligned along a z-axis, wherein a spin magnetization with a given target distribution of magnetization is generated, and for refocusing the spin magnetization, is characterized in that the radio frequency pulse is used as a sequence of sub-pulses of independent duration, courses of gradients and spatial and/or spectral resolution, comprising one or more large angle RF pulses with tip angles greater than or approximately equal to 15°, which generate a gross distribution of magnetization approximating the target distribution of magnetization or a desired modification of the distribution of magnetization with a mean deviation less than or approximately equal to 15°, wherein the actual effect of the LAPs on the distribution of spin magnetization before

Abstract: A method to compensate for the magnetic field heterogeneity inside an object of investigation in a MR device obtains an uncorrected magnetic field distribution of the object and executes an MR sequence with a desired k-space coverage by applying RF pulses to generate a transverse magnetization within the object. MR signal data is recorded, magnetic field shimming parameters are dynamically updated and MR signal data are reconstructed to produce images or localized spectroscopic data. Artifacts in a reconstructed image resulting from an uncorrected magnetic field distribution are suppressed by temporally separating MR signals originating from at least two different sub-volumes within a volume of transverse magnetization by generating a nonlinear phase distribution within the object and by dynamically updating shimming parameters to compensate for the field inhomogeneity distributions within the different sub-volumes in the volume of transverse magnetization.

Abstract: The pursuit for ever higher field strengths and faster data acquisitions has led to the construction of coil arrays with high numbers of elements. With the SENSE technique it has been shown, how the sensitivity of those elements can be used for spatial image encoding. A method in accordance with the present invention, largely abstains from using encoding gradients. The resulting sensitivity encoded free induction decay (FID) data is then not used for imaging, but for determining field inhomogeneity distribution. The method has therefore been termed SSH for Sense SHimming.

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: The pursuit for ever higher field strengths and faster data acquisitions has led to the construction of coil arrays with high numbers of elements. With the SENSE technique it has been shown, how the sensitivity of those elements can be used for spatial image encoding. A method in accordance with the present invention, largely abstains from using encoding gradients. The resulting sensitivity encoded free induction decay (FID) data is then not used for imaging, but for determining field inhomogeneity distribution. The method has therefore been termed SSH for Sense SHimming.

Abstract: A magnetic resonance method for using radio frequency pulses for spatially selective and frequency selective or multidimensionally spatially selective excitation of an ensemble of nuclear spins with an initial distribution of magnetization in a main magnetic field aligned along a z-axis, wherein a spin magnetization with a given target distribution of magnetization is generated, and for refocusing the spin magnetization, is characterized in that the radio frequency pulse is used as a sequence of sub-pulses of independent duration, courses of gradients and spatial and/or spectral resolution, comprising one or more large angle RF pulses with tip angles greater than or approximately equal to 15°, which generate a gross distribution of magnetization approximating the target distribution of magnetization or a desired modification of the distribution of magnetization with a mean deviation less than or approximately equal to 15°, wherein the actual effect of the LAPs on the distribution of spin magnetization before

Abstract: A magnetic resonance tomography apparatus, includes a gradient system that can generate at least one spatially varying and optionally time-varying magnetic field for at least one-dimensional local encoding of measuring signals in an area of a test sample to be imaged. The gradient system contains at least one subsystem which can generate a non-bijective spatially varying magnetic (NBSEM) field for local encoding, such that the function of the field strength of such an NBSEM within the area to be imaged has at least one local extreme value (maximum or minimum), such that the area to be imaged is divided along the hyper surface formed by the entirety of all local extreme values of the at least one NBSEM. The apparatus can produce images of the same quality with smaller magnetic field differences and permits easy realization.

Abstract: A magnetic resonance tomography apparatus, comprising a gradient system that can generate at least one spatially varying and optionally time-varying magnetic field for at least one-dimensional local encoding of measuring signals in an area of a test sample to be imaged, is characterized in that the gradient system contains at least one subsystem which can generate a non-bijective spatially varying magnetic field (=NBSEM or ambivalent/non-bijective spacially encoding magnetic field) for local encoding, such that the function of the field strength of such an NBSEM within the area to be imaged has at least one local extreme value (maximum or minimum), such that the area to be imaged is divided along the hyper surface formed by the entirety of all local extreme values of the at least one NBSEM into ng partial areas, with ng?2, that the magnetic field profile has a non-unidirectional distribution within and/or over these partial areas, and that least ng receiver coils are provided which have a differing sensitivit

Abstract: A nuclear magnetic resonance (NMR) tomography method for investigating a target object, wherein radio frequency (RF) pulses are irradiated into a target volume and/or RF pulses from the target volume are detected, wherein the target volume is determined by the frequency of the RF pulses and/or through magnetic field gradients, and wherein the target object is moved relative to the NMR tomograph during NMR data acquisition, is characterized in that the frequency of the RF pulses and/or the magnetic field gradients is/are changed during NMR data acquisition such that the target volume covered by the RF pulses is moved relative to the NMR tomograph at the same speed and direction of motion as the target object during NMR data acquisition. This provides a method for investigating a target object which moves relative to the NMR tomograph during NMR data acquisition, which can be carried out in a fast and simple manner.

Abstract: A nuclear magnetic resonance (NMR) tomography method for investigating a target object, wherein radio frequency (RF) pulses are irradiated into a target volume and/or RF pulses from the target volume are detected, wherein the target volume is determined by the frequency of the RF pulses and/or through magnetic field gradients, and wherein the target object is moved relative to the NMR tomograph during NMR data acquisition, is characterized in that the frequency of the RF pulses and/or the magnetic field gradients is/are changed during NMR data acquisition such that the target volume covered by the RF pulses is moved relative to the NMR tomograph at the same speed and direction of motion as the target object during NMR data acquisition. This provides a method for investigating a target object which moves relative to the NMR tomograph during NMR data acquisition, which can be carried out in a fast and simple manner.

Abstract: A nuclear magnetic resonance (NMR) spectroscopy or tomography method wherein a sequence of temporally mutually offset radio frequency (RF) pulses is applied onto a spin ensemble like a CPMG multi echo experiment, and wherein the magnetization produced after an initial excitation pulse is transferred to or close to the static pseudo steady state of the initially applied refocussing flip angle ?1 is characterized in that magnetization is transferred through gradual change of the refocussing flip angle in subsequent refocussing intervals to or close to the static pseudo steady state of the respectively used refocussing pulse with refocussing flip angle ?n such that the echo amplitude of the nth echo generated in this fashion approaches the maximum possible value corresponding to the respective refocussing pulse with refocussing flip angle ?n. The RF energy required for excitation of the nuclear spins can thereby be considerably reduced without having to accept signal intensity losses.

Abstract: A nuclear magnetic resonance (NMR) tomography method for investigating a target object, wherein radio frequency (RF) pulses are irradiated into a target volume and/or RF pulses from the target volume are detected, wherein the target volume is determined by the frequency of the RF pulses and/or through magnetic field gradients, and wherein the target object is moved relative to the NMR tomograph during NMR data acquisition, is characterized in that the frequency of the RF pulses and/or the magnetic field gradients is/are changed during NMR data acquisition such that the target volume covered by the RF pulses is moved relative to the NMR tomograph at the same speed and direction of motion as the target object during NMR data acquisition. This provides a method for investigating a target object which moves relative to the NMR tomograph during NMR data acquisition, which can be carried out in a fast and simple manner.

Abstract: A method of MRT according to the principle of signal generation in the driven equilibrium (DE) or also steady state free precession (SFP) wherein a periodic sequence of RF pulses with a flip angle &agr; is applied with a time delay TR wherein the phase of these pulses is alternated in subsequent steps, is characterized in that the periodic sequence of RF pulses is preceded by a sequence of (n+1) pulses for which the following conditions are valid: a first excitation pulse with preferred flip angle &agr;0=90° precedes the subsequently equidistant sequence of RF pulses at a preferred separation TR/2, the flip angle &agr;1 of the subsequent pulse is larger than &agr; and identical or approximately identical to 180°, the flip angle &agr;1 of the i-th pulse in the region i=2 . . . n is selected such that &agr;i≦&agr;i-1 and &agr;i≧&agr; and the phases of these pulses alternate.

Abstract: A method of magnetic resonance (NMR) for spatially resolved measurement of the distribution of NMR signals of metabolites (CSI) with low signal intensity, wherein on a spin ensemble, a sequence of radio frequency (RF) pulses is applied which are mutually offset by a time interval of a repetition time TR and magnetic gradient fields are switched of which at least one causes spatial encoding of the excited spins, is characterized in that the repetition time TR between the exciting RF pulses is selected to be at the most in the magnitude transverse relaxation time T2* of the spins to be excited, preferably approximately T2*/10 and that the magnetic gradient fields are selected such that their action integral is completely balanced over a repetition period of a time period TR such that NMR signal production is carried out according to the principle of steady state free precession (SSFP).