Abstract: In a method and apparatus for quantitative magnetic resonance (MR), MR signals of a subject volume are acquired using various values of at least one acquisition parameter. First and second functions are respectively specified, by which an MR signal can be determined, depending on a first parameter and the at least one acquisition parameter, and depending on a second parameter and the at least one acquisition parameter. First and second subsets of the MR signals are determined respectively for the first parameter and the second parameter. The first subset differs from the second subset. The first and second parameters are determined respectively such that MR signals calculated using the first function correspond as closely as possible to the MR signals of the first subset, and MR signals calculated using the second function correspond as closely as possible to the MR signals of the second subset.

Abstract: In a magnetic resonance (MR) apparatus and a method for operating such an apparatus, a T1 parameter map is generated with fat fraction correction, by using a model in which the fat fraction of acquired MR data is used as a known parameter. The T1 values from the acquired MR data are fat fraction-corrected in such a manner, so as to generate fat fraction-corrected entries for the T1 parameter map according to the model.

Abstract: In a magnetic resonance method and apparatus for determination of a measurement variable that is relevant to a function of an organ of a patient, a first longitudinal relaxation rate R11 is determined before a contrast medium is administered to the patient. A second longitudinal relaxation rate R12 is determined after a contrast medium is administered to the patient. A property of the contrast medium in the organ is determined based on R11 and R12. The measurement variable is determined based on the property of the contrast medium in the organ.

Abstract: In a method and magnetic resonance (MR) apparatus for reconstruction of image data of an examination object from undersampled raw MR data and reference data, undersampled raw data are used that were recorded from an examination region of the examination object by an MR control sequence, to which a reconstruction algorithm for the reconstruction of image data is assigned. A disturbance variable in the examination region is determined. A modulation function is established, which describes the influence of the disturbance variable on the MR control sequence. Modulated reference data are created on the basis of the modulation function and the reference data such that the modulated reference data are subjected to the influence of the disturbance variable on the raw data recorded by the MR control sequence. A combination algorithm is executed in order to reconstruct image data from the undersampled raw data with the use of the modulated reference data.

Abstract: In a method and a magnetic resonance system to determine the T1 time of water and the T1 time of fat in a predetermined volume segment of an examination subject, magnetic field gradients are activated to generate multiple gradient echoes. First echoes are acquired at at least two different echo times based on RF pulses with a first flip angle. A first water magnetization and a first fat magnetization are determined for each voxel of the volume segment from the first echoes, according to the Dixon method. Second echoes are acquired at at least two different echo times based on RF pulses with a second flip angle. A second water magnetization and a second fat magnetization are determined for each voxel of the volume segment depending on the second echoes according to the Dixon method.

Abstract: In a magnetic resonance (MR) apparatus and method to evaluate the consistency of a signal model used to generate a quantitative parameter map, the residual of the quantitative parameter map is calculated and a residual map is generated. The residual map is displayed together with the quantitative parameter map, with the residual map serving as an indicator of the quality of fit of the signal model.

Abstract: In a method and computer for creating a usage schedule during a usage phase of an image acquisition apparatus, time slots of the usage phase are assigned to examinations of a patient that use at least one measurement protocol. The scheduling is performed using examination durations associated with the examinations based on at least one examination parameter specifying the examination and/or at least one patient parameter specifying the patient, as input data, determined by an analysis algorithm using operating data that are recorded during the operation of the image acquisition apparatus and/or an image acquisition apparatus allocated to a group of image acquisition apparatuses of the same imaging modality.

Abstract: In a magnetic resonance (MR) apparatus and a method for operating an MR apparatus, MR data are acquired and evaluated with regard to multiple tentative signal models for producing a parameter map based on one of those signal models. The parameter map shows multiple parameters that have respective effects on the MR data. Each tentative signal model is initially analyzed to determine whether any of the parameters used therein can be assumed to be at least locally constant, and the initially analyzed tentative signal model is then subjected at least to a quality of fit analysis. The tentative signal model having at least the best quality of fit analysis result is then used to generate a parameter map that is displayed at a display monitor.

Abstract: In a method and a magnetic resonance system for acquisition of spectroscopy data in a predetermined volume segment of an examination subject, spectroscopy data in the volume segment are acquired in multiple measurement steps, and spatially resolved MR data of the examination subject also are acquired in multiple measurement steps. Each of the measurement steps to acquire the spectroscopy data or to acquire the MR data respectively includes an excitation step and a readout step associated with that excitation step. At least one of the measurement steps to acquire the MR data occurs between one of the measurement steps to acquire the spectroscopy data and another of the measurement steps to acquire the spectroscopy data.

Abstract: In a magnetic resonance method and apparatus for determination of a measurement variable that is relevant to a function of an organ of a patient, a first longitudinal relaxation rate R11 is determined before a contrast medium is administered to the patient. A second longitudinal relaxation rate R12 is determined after a contrast medium is administered to the patient. A property of the contrast medium in the organ is determined based on R11 and R12. The measurement variable is determined based on the property of the contrast medium in the organ.

Abstract: In a computer and a magnetic resonance method and apparatus for automatic characterization (classification) of liver tissue in a region of interest of a liver, at least one value tuple of the region of interest of the liver is acquired, the value tuple including at least one T1 value determined from magnetic resonance images of the region of interest, or a reciprocal value thereof, and a T2 or T2* value or a reciprocal value thereof. The value tuple is transferred into a multidimensional parameter space and the characterization of the liver tissue is then performed on the basis of the position of the value tuple in the parameter space.

Abstract: In a method and magnetic resonance (MR) apparatus to acquire MR data from a subject, a predetermined spectral model of a multipoint Dixon technique is used that includes at least two spectral components with respective associated relaxation rates, a first phase due to field inhomogeneities; and a second phase due to eddy current effects. MR data are acquired using a bipolar multi-echo MR measurement sequence for multiple image points wherein, for each image point, the multi-echo MR measurement sequence alternately uses positive and negative readout gradient fields for the readout of MR signals of the MR data at at least three echo times. The at least two spectral components are determined based on the MR data.

Abstract: In a method and magnetic resonance (MR) apparatus for reconstruction of image data of an examination object from undersampled raw MR data and reference data, undersampled raw data are used that were recorded from an examination region of the examination object by an MR control sequence, to which a reconstruction algorithm for the reconstruction of image data is assigned. A disturbance variable in the examination region is determined. A modulation function is established, which describes the influence of the disturbance variable on the MR control sequence. Modulated reference data are created on the basis of the modulation function and the reference data such that the modulated reference data are subjected to the influence of the disturbance variable on the raw data recorded by the MR control sequence. A combination algorithm is executed in order to reconstruct image data from the undersampled raw data with the use of the modulated reference data.

Abstract: In a method and apparatus for the automatic assignment of at least one combination image of an examination object to a spin species represented in a combination magnetic resonance (MR) image, an information MR dataset is obtained and evaluated in a computer to determine information about the examination object from the captured information MR dataset. At least two MR datasets are acquired at one of at least two echo times in each case following an excitation by a multi-contrast measurement. At least one combination image is determined from the at least two MR datasets, and spin species represented in the at least one combination image are assigned on the basis of the information determined from the information MR dataset. By using additional information about the examination object determined by MR technology an automatic unambiguous global assignment of the correct spin species is enabled.

Abstract: A method for denoising Magnetic Resonance Imaging (MRI) data includes receiving a noisy image acquired using an MRI imaging device and determining a noise model comprising a non-diagonal covariance matrix based on the noisy image and calibration characteristics of the MRI imaging device. The noisy image is designated as the current best image. Then, an iterative denoising process is performed to remove noise from the noisy image.

Abstract: In a method and magnetic resonance apparatus for determining a scanning region that is relevant to a magnetic resonance examination, overview data are acquired from an object positioned on a patient accommodation device during total imaging, the overview data are evaluated so as to generate position information therefrom relating to the object positioned on the patient accommodation device on the basis of the overview data, and the scanning region that is relevant to the magnetic resonance examination is determined on the basis of the position information.

Abstract: A method for denoising magnetic resonance images includes estimating a normalization field corresponding to a magnetic resonance imaging device and acquiring a non-normalized image from the magnetic resonance imaging device. A noise level estimation process is performed with the non-normalized image to yield a noise level. The normalization field is applied to the noise level to yield a potentially inhomogeneous noise-level map and to the non-normalized image to yield a normalized image. An adaptive polynomial filtering process is performed using the normalized image and the potentially inhomogeneous noise-level map to yield a denoised image.

Abstract: A method for denoising Magnetic Resonance Imaging (MRI) data includes receiving a noisy image acquired using an MRI imaging device and determining a noise model comprising a non-diagonal covariance matrix based on the noisy image and calibration characteristics of the MRI imaging device. The noisy image is designated as the current best image. Then, an iterative denoising process is performed to remove noise from the noisy image.

Abstract: In a method and apparatus to determine a magnetic resonance image of an examination subject with at least two spin species by using a chemical shift imaging multi-echo MR measurement sequence, first approximated MR image is determined based on a first approximative model and of a second approximated MR image is determined based on a second approximative model, wherein the first and second approximative model respectively express an MR signal under consideration of one or more MR parameters, and wherein the first and second approximative model differ with regard to the consideration of at least one MR parameter. The MR image is determined from a mean calculation that depends on the first and second approximated MR image.

Abstract: In a method and apparatus for determining time-dependent dephasing factors of at least one spectral component of at least two spectral components in a region of interest in an object under examination, measured data of the region of interest and acquired over time by a test measurement in a magnetic resonance scanner. The contribution of at least one of the at least two spectral components in the recorded measured data is determined. Dephasing factors of the at least one spectral component are determined on the basis of the contribution determined therefor in the recorded measured data over time. Dephasing factors determined in this way can be determined individually with relatively little effort and used in Dixon techniques.