Abstract: A method of dynamic magnetic resonance imaging comprising acquiring undersampled magnetic resonance signals for successive temporal time slots. In a space spanned by geometrical space and temporal frequency and on the basic of a priori information the aliased difference magnetic resonance data which are gained by subtracting for respective k-space sampling positions data of a baseline magnetic resonance image from the undersampled magnetic resonance signals are decomposed into difference data which essentially pertain to individual spatial positions at individual time slots.

Abstract: This invention describes the combination of SSFP, a method for accelerating data acquisition, and an eddy current compensation method. This synergistic combination allows acquisition of images with high signal-to-noise ratio, high image contrast, high spatial and temporal resolutions, and good immunity against system instabilities. k-t BLAST and k-t SENSE are the preferred method for accelerating data acquisition, since they allow high acceleration factors, but other methods such as parallel imaging and reduced field-of-view imaging are also applicable. Typical applications of this invention include cine 3D cardiac imaging, and 2D real-time cardiac imaging.

Abstract: In a magnetic resonance imaging method an echo train is generated of successive magnetic resonance signals from an object to be examined. The magnetic resonance signals are received with a degree of undersampling and by means of a receiver antennae system having a spatial sensitivity profile and the degree of undersampling is set on the basis of an amount of phase evolution due to a magnetic susceptibility distribution of the object to be examined.

Abstract: The present invention describes a magnetic resonance imaging method wherein spatially resolved frequency sensitive image data are collected by means of free precession sequences employing very small radio frequency (RF) excitation pulses per unit time which result in highly frequency selective steady-state signals dominated by linear properties of the system, for which the superposition principle holds. By appropriate linear combination of steady state signals of N different frequencies, N resonance lines can be acquired simultaneously. This method allows spectroscopic recordings with very low RF power deposition which renders the method suitable for applications at high static magnetic field strengths.

Abstract: This invention describes the combination of SSFP, a method for accelerating data acquisition, and an eddy current compensation method. This synergistic combination allows acquisition of images with high signal-to-noise ratio, high image contrast, high spatial and temporal resolutions, and good immunity against system instabilities. k-t BLAST and k-t SENSE are the preferred method for accelerating data acquisition, since they allow high acceleration factors, but other methods such as parallel imaging and reduced field-of-view imaging are also applicable. Typical applications of this invention include cine 3D cardiac imaging, and 2D real-time cardiac imaging.

Abstract: A magnetic resonance imaging system comprises means for generating a main magnetic field with a main magnetic field strength an a plurality of magnetic resonance signal receiving positions, provided by one or more receiver antennae. The receiver antennae or coils have a spatial sensitivity profile for acquiring magnetic resonance signals at a predetermined degree of undersampling. Further means for reconstructing a magnetic resonance image from the set of undersampled magnetic resonance signals and the spatial sensitivity profiles are provided. In addition, means are provided for determining the degree of undersampling (R) in dependency of the given main field strength (B0) and the selected field-of-view (FOV).

Abstract: The present invention describes a magnetic resonance imaging method wherein spatially resolved frequency sensitive image data are collected by means of free precession sequences employing very small radio frequency (RF) excitation pulses per unit time which result in highly frequency selective steady-state signals dominated by linear properties of the system, for which the superposition principle holds. By appropriate linear combination of steady state signals of N different frequencies, N resonance lines can be acquired simultaneously. This method allows spectroscopic recordings with very low RF power deposition which renders the method suitable for applications at high static magnetic field strengths.

Abstract: Successive magnetic resonance images are reconstructed from the respective sets of magnetic resonance signals of the dynamic series on the basis of the identified distribution of likelihood of changes and optionally the static reference image. The magnetic resonance signals are acquired by way of a receiver antennae system having a spatial sensitivity profile and in an undersampled fashion and the successive magnetic resonance images are reconstructed optionally also on the basis of the spatial sensitivity profile.

Abstract: A novel combination of free-breathing navigator-gated 3D coronary magnetic resonance angiography with SENSE imaging is described. Applying a SENSE reduction factor of two at a main magnet field of 3 T allows to image long portions of the left and the right coronary artery system during half of the scan time, when compared to normal acquisition.

Abstract: In a magnetic resonance imaging method an echo train is generated of successive magnetic resonance signals from an object to be examined.

Abstract: In a magnetic resonance imaging system the receiver antennae system includes receiver coils which are electromagnetically coupled with a relative coupling degree in the range (?, 0.5), preferably in the range (?, 0.2).

Abstract: Successive magnetic resonance images are reconstructed from the respective sets of magnetic resonance signals of the dynamic series on the basis of the identified distribution of likelihood of changes and optionally the static reference image. The magnetic resonance signals are acquired by way of a receiver antennae system having a spatial sensitivity profile and in an undersampled fashion and the successive magnetic resonance images are reconstructed optionally also on the basis of the spatial sensitivity profile.

Abstract: In SENSitivity Encoding (SENSE), the reconstructed images are susceptible to amplified noise and/or artifacts if the underlying matrix inversion procedure is ill-conditioned. In this work, we propose to firstly apply the conventional SENSE algorithm to obtain an initial estimate. This initial estimate undergoes filtering to improve the signal-to-noise ratio. Then, it is fed back to the reconstruction as a reference image to estimate the amount of aliasing that may arise from regularization. We derive the optimal regularized solution that minimizes the weighted sum of artifact and noise power.

Abstract: A magnetic resonance imaging system comprises means for generating a main magnetic field with a main magnetic field strength an a plurality of magnetic resonance signal receiving positions, provided by one or more receiver antennae. The receiver antennae or coils have a spatial sensitivity profile for acquiring magnetic resonance signals at a predetermined degree of undersampling. Further means for reconstructing a magnetic resonance image from the set of undersampled magnetic resonance signals and the spatial sensitivity profiles are provided. In addition, means are provided for determining the degree of undersampling (R) in dependency of the given main field strength (B0) and the selected field-of-view (FOV).

Abstract: A method of dynamic magnetic resonance imaging comprising acquiring undersampled magnetic resonance signels for successive temporal time slots. In a space spanned by geometrical space and temporal frequency and on the basic of a priori information the aliased difference magnetic resonance data which are gained by subtracting for respective k-space sampling positions data of a baseline magnetic resonance image from the undersampled magnetic resonance signals are decomposed into difference data which essentially pertain to individual spatial positions at individual time slots.

Abstract: A magnetic resonance method is described for forming a fast dynamic image with an automatically generated grid of essentially orthogonally arranged grid lines by a saturation information induced over the object to be imaged. Therefore a first set of parallel saturation planes is obtained by applying a first nonselective RF pulse with a flip angle of 90°, an intermediate magnetic field gradient pulse in direction of the spatial modulation, and a second nonselective RF pulse with a flip angle of 90°. A subsequent spoiler gradient pulse is applied in the direction of the magnetic field gradient for slice selection. Subsequently a second set of parallel saturation planes is obtained in the same manner by inverting one second RF pulse with respect to the first RF pulse. Further the first and the sets of saturation planes are subtracted from each other to obtain a grid free of any contribution of relaxation components of magnetization.

Abstract: A magnetic resonance method is described for forming a fast dynamic image with an automatically generated grid of essentially orthogonally arranged grid lines by a saturation information induced over the object to be imaged. Therefore a first set of parallel saturation planes is obtained by applying a first nonselective RF pulse with a flip angle of 90°, an intermediate magnetic field gradient pulse in direction of the spatial modulation, and a second nonselective RF pulse with a flip angle of 90°. A subsequent spoiler gradient pulse is applied in the direction of the magnetic field gradient for slice selection. Subsequently a second set of parallel saturation planes is obtained in the same manner by inverting one second RF pulse with respect to the first RF pulse. Further the first and the sets of saturation planes are subtracted from each other to obtain a grid free of any contribution of relaxation components of magnetization.

Abstract: The invention relates to a method for obtaining images by means of magnetic resonance (MR) of an object placed in a static magnetic field which method includes simultaneous measurement of a number sets of MR signals by application gradients and an array of receiver coils, reconstruction of a number of receiver coil images from the sets MR signals measured and reconstruction of a final image from a distant dependent sensitivity of the receiver coils and the first plurality of receiver coil images. In order to reduce the acquisition time the number of phase encoding steps corresponding to the phase-encoding gradient is reduced with a reduction factor compared to standard Fourier imaging, while a same field of view is maintained as in standard Fourier imaging. In this way fast cardiac imaging may be possible.

Abstract: The invention relates to a magnetic resonance method for determining a perfusion image of a portion, which method comprises the following steps: generation of a control pulse sequence in a first portion of the body and measurement of a control data set by generation of an MR-image sequence for imaging of an third portion of the body, generation of a labelling pulse sequence in a second portion of the body wherein a fluid flows towards the third portion, and measurement of the labelled data set by generation of the MR-image sequence for imaging the third portion of the body, and reconstruction of the perfusion image of the fluid in a mass of the third portion of the body from a combination of the control data set and the labelled data set.

Abstract: The invention relates to a method for determining an image of a portion of a body by means of magnetic resonance (MR), which method comprises a step for rotating a magnetization of spins in a selected portion of the body and by generating an RF pulse in a selected slice. The RF pulse comprises a concatenation of a selective first RF pulse and a second selective RF pulse.