Abstract: In a method for creating a composite magnetic resonance (MR) raw dataset for an MR apparatus, a first MR raw dataset is determined from a first partial section of an examination object, in which a first region of the first MR raw dataset is not filled with MR signals and in which a second region of the first MR raw dataset is filled with MR signals. An MR overview dataset is determined, which has been acquired with a number of reception coils of the MR apparatus and for which an overall field of view of the number of MR coils is larger than a reception region of the number of MR receive coils. A partial dataset is determined from the MR overview dataset, which has MR signals that originate from the first partial section of the examination object from which the first MR raw dataset originates. MR partial raw data are reconstructed for the first region of the MR raw dataset, using the partial dataset determined.

Abstract: In a method according to optimize the noise development of a 3D gradient echo sequence in a magnetic resonance system, an optimization of at least one parameter of the gradient echo sequence, from the group including: the excitation pulse (the duration of the excitation pulse); the order of k-space lines to be scanned in k-space; and the readout direction of the k-space lines to be scanned in k-space, is implemented such that the gradients to be switched have optimally minimal slew rates, amplitudes and/or polarity changes.

Abstract: In a method for creating a composite magnetic resonance (MR) raw dataset for an MR apparatus, a first MR raw dataset is determined from a first partial section of an examination object, in which a first region of the first MR raw dataset is not filled with MR signals and in which a second region of the first MR raw dataset is filled with MR signals. An MR overview dataset is determined, which has been acquired with a number of reception coils of the MR apparatus and for which an overall field of view of the number of MR coils is larger than a reception region of the number of MR receive coils. A partial dataset is determined from the MR overview dataset, which has MR signals that originate from the first partial section of the examination object from which the first MR raw dataset originates. MR partial raw data are reconstructed for the first region of the MR raw dataset, using the partial dataset determined.

Abstract: In a method and magnetic resonance apparatus for acquiring a sensitivity map for at least one local coil in a magnetic resonance scanner, the extent of k-space to be sampled is divided into a first part located around the center of k-space, and a second part. First and the second magnetic resonance data sets are acquired with undersampling in at least one phase-coding direction in the second part, and are acquired globally in the first part. An accelerated parallel magnetic resonance imaging reconstruction technique is executed for the reconstruction of magnetic resonance data that are missing in the magnetic resonance raw data sets due to the undersampling, to produce a global data set defined by combining the first and the second magnetic resonance global data sets. Supplemented first and second magnetic resonance data sets are acquired by adding the reconstructed magnetic resonance data in the regions not covered in the undersampling.

Abstract: In a method according to optimize the noise development of a 3D gradient echo sequence in a magnetic resonance system, an optimization of at least one parameter of the gradient echo sequence, from the group including: the excitation pulse (the duration of the excitation pulse); the order of k-space lines to be scanned in k-space; and the readout direction of the k-space lines to be scanned in k-space, is implemented such that the gradients to be switched have optimally minimal slew rates, amplitudes and/or polarity changes.

Abstract: In a method processor and magnetic resonance (MR) system to generate MR slice exposures of an examination subject, measurement data for a stack of measurement slices through the examination subject are initially acquired using a series of slice measurement sequences. The series of slice measurement sequences is designed to allow a separation of a first material from a second material that has a defined chemical shift relative to said first material, and the position of a measurement slice with measurement data for the first material is spatially shifted relative to the position of a measurement slice with measurement data for the second material.

Abstract: In a methods and devices for magnetic resonance (MR) imaging, an MR data acquisition is implemented repeatedly in which an examination subject is exposed to an alternating magnetic field with a frequency before the readout sequence. The signal values acquired after the preparation of the magnetization with alternating fields of respectively different frequencies are evaluated. Magnetic field data that contain information about the curve of the basic field are used to implement the MR data acquisitions, such as to establish the frequencies, and/or in the evaluation of the signal values.

Abstract: In a method and magnetic resonance system to determine a magnetic resonance (MR) image of an examination subject, wherein multiple coil-specific MR data sets that are acquired by multiple coils are used for the MR image. Each pixel of the MR image is determined from at least two coil-specific MR data sets of different coils (6-10), and each pixel has a pixel magnitude and a pixel phase. Multiple coil-specific base phases are determined that are respectively associated with one of the multiple coils. For each pixel multiple coil-specific pixel, magnitudes and multiple pixel phases are determined. A coil-specific pixel magnitude and a coil-specific pixel phase are respectively determined from a coil-specific MR data set of one of the multiple coils (7-10). The coil-specific pixel phases with the corresponding, coil-specific base phase, and the multiple coil-specific pixel magnitudes and the multiple coil-specific pixel phases are combined into the pixel magnitude and the pixel phase of the pixel.

Abstract: A method is disclosed for determining an attenuation map for use in positron emission tomography and for the use of homogeneity information relating to the magnetic resonance magnetic field, in particular for the purpose of determining shim settings, within the scope of a single magnetic resonance image recording. In at least one embodiment of the method, a first and a second image data record are firstly recorded with a three-dimensional gradient echo sequence during a first and a second echo time, respectively, with the phase difference between the water and the fat signal amounting to zero during the first echo time and amounting to 180 degrees during the second echo time. The attenuation map is determined from fat/water ratios obtained from the image data records by way of a Dixon technology, in particular a 2-point Dixon technology.

Abstract: In a method processor and magnetic resonance (MR) system to generate MR slice exposures of an examination subject, measurement data for a stack of measurement slices through the examination subject are initially acquired using a series of slice measurement sequences. The series of slice measurement sequences is designed to allow a separation of a first material from a second material that has a defined chemical shift relative to said first material, and the position of a measurement slice with measurement data for the first material is spatially shifted relative to the position of a measurement slice with measurement data for the second material.

Abstract: In a magnetic resonance method and system to correct spatial shifts in MR data, at least two measurement data sets are acquired, the additional measurement data set or sets being acquired while switching an additional gradient relative to acquisition of the first measurement data set. For respective corresponding measurement points of the measurement data sets, a phase difference is initially determined from the first measurement data set and at least one additional measurement data set acquired with the additional gradient, with a spatial shift of the measurement points of the first measurement data set being determined from the spatial shift. The magnitude values of the initially measured measurement points are distributed to their correct spatial position corresponding to the determined spatial shifts, so a corrected image data set is created.

Abstract: In a magnetic resonance method and system to automatically differentiate whether a pixel of an MR image acquired with magnetic resonance system originated from fat-dominated tissue or water-dominated tissue, only one spin echo-based magnetic resonance signal per pixel is acquired at a point in time at which the phase of a magnetic resonance signal of aqueous tissue has a phase opposite to the phase of a magnetic resonance signal of fat tissue. The phase angle of the pixel is then calculated, a base phase at the pixel depending on the magnetic resonance system is determined, and a corrected phase angle of the pixel is determined from the phase angle and the base phase. Whether the pixel originated from fat-dominated tissue or water-dominated tissue is then determined using the corrected phase angle of the pixel.

Abstract: In a magnetic resonance method and device for automatic differentiation of respective pixels as representing either a silicon-dominated substance, or fat-dominated tissue, or water-dominated tissue, a first magnetic resonance signal and a second magnetic resonance signal are acquired per pixel, wherein the first magnetic resonance signal per pixel is acquired at a point in time at which the phase of a magnetic resonance signal originating from water-containing tissue exhibits a phase opposite to the phase of a magnetic resonance signal originating from fat-containing tissue, and the second magnetic resonance signal is acquired per pixel at a point in time at which the phase of the magnetic resonance signal originating from water-containing tissue exhibits a phase identical to the phase of the magnetic resonance signal originating from fat-containing tissue, and the phase of a magnetic resonance signal originating from a silicon-containing substance exhibits a phase opposite to the phase of the magnetic resona

Abstract: In a magnetic resonance tomography method and apparatus for separation of fat and water images according to the two-point Dixon method dependent on the T*2 decay, the following steps are implemented: (S1) acquire three fat-water images, respectively corresponding to the echo times TE1, TE2, TE3 after the RF excitation pulse, wherein first and third fat-water images exhibit the same phase, (S2) calculate a T*2 map from the two equiphase images, (S3) correct the T*2 influence in one of the two equiphase fat-water images and in the counter-phase fat-water image, and (S4) reconstruct a pure T*2-corrected fat image and a pure T*2-corrected water image according to the two-point Dixon method on the basis of the T*2-corrected equiphase and counter-phase fat-water images in Step (S3).

Abstract: In a method and magnetic resonance system to determine a magnetic resonance (MR) image of an examination subject, wherein multiple coil-specific MR data sets that are acquired by multiple coils are used for the MR image. Each pixel of the MR image is determined from at least two coil-specific MR data sets of different coils (6-10), and each pixel has a pixel magnitude and a pixel phase. Multiple coil-specific base phases are determined that are respectively associated with one of the multiple coils. For each pixel multiple coil-specific pixel, magnitudes and multiple pixel phases are determined. A coil-specific pixel magnitude and a coil-specific pixel phase are respectively determined from a coil-specific MR data set of one of the multiple coils (7-10). The coil-specific pixel phases with the corresponding, coil-specific base phase, and the multiple coil-specific pixel magnitudes and the multiple coil-specific pixel phases are combined into the pixel magnitude and the pixel phase of the pixel.

Abstract: In a methods and devices for magnetic resonance (MR) imaging, an MR data acquisition is implemented repeatedly in which an examination subject is exposed to an alternating magnetic field with a frequency before the readout sequence. The signal values acquired after the preparation of the magnetization with alternating fields of respectively different frequencies are evaluated. Magnetic field data that contain information about the curve of the basic field are used to implement the MR data acquisitions, such as to establish the frequencies, and/or in the evaluation of the signal values.

Abstract: A method corrects for a phase error in an MR image, in which MR signals of an examination subject are acquired, complex images of the examination subject are generated, phase differences of the phase values for various image points of the complex images are established with an averaged phase value of image points from a first surrounding region of a respective image point, and a phase correction is executed dependent on how well the phase differences correspond to a predetermined phase value, where the order of the image points in which the phase correction is implemented is dependent on how well the phase values in the image points correspond to the predetermined phase value.

Abstract: In a method, apparatus and computer-readable medium for magnetic resonance imaging of a contiguous region of a human body on the basis of partially parallel acquisition (PPA) by excitation of nuclear spins and measurement of radio-frequency signals representing the excited spins, are implemented. A k-space single channel reference image [R_kal] is calculated from the previously measured reference lines of a sub-coil series of N sub-coils with a phase-sensitive combination method. A GRAPPA coefficient matrix [W] is calculated by solving the equation system [R_kal]=[W]×[I_kal] wherein [I_kal] represents one block from the sub-coil series. A k-space single channel image [R] is successively completed by applying [W] to successive blocks [I_z] shifted relative to one another, the blocks [I_z] being of a previously measured, under-sampled sub-coil series of the N sub-coils, and [R] is transformed into image space.

Abstract: In a magnetic resonance method and device for automatic differentiation of respective pixels as representing either a silicon-dominated substance, or fat-dominated tissue, or water-dominated tissue, a first magnetic resonance signal and a second magnetic resonance signal are acquired per pixel, wherein the first magnetic resonance signal per pixel is acquired at a point in time at which the phase of a magnetic resonance signal originating from water-containing tissue exhibits a phase opposite to the phase of a magnetic resonance signal originating from fat-containing tissue, and the second magnetic resonance signal is acquired per pixel at a point in time at which the phase of the magnetic resonance signal originating from water-containing tissue exhibits a phase identical to the phase of the magnetic resonance signal originating from fat-containing tissue, and the phase of a magnetic resonance signal originating from a silicon-containing substance exhibits a phase opposite to the phase of the magnetic resona

Abstract: A method corrects for a phase error in an MR image, in which MR signals of an examination subject are acquired, complex images of the examination subject are generated, phase differences of the phase values for various image points of the complex images are established with an averaged phase value of image points from a first surrounding region of a respective image point, and a phase correction is executed dependent on how well the phase differences correspond to a predetermined phase value, where the order of the image points in which the phase correction is implemented is dependent on how well the phase values in the image points correspond to the predetermined phase value.