Abstract: In a method and apparatus for determination of phase distributions in MR imaging, a measured phase distribution of the region of interest is combined with at least one second phase value to form a combination-phase distribution, wherein the phase values of the combination-phase distribution are restricted to a defined presentation interval. A correction-phase distribution is generated, based on a known magnetic field distribution in the region of interest. The phase values thereof are not restricted to the defined presentation interval. A corrected combination-phase distribution is generated using the correction-phase distribution and the combination-phase distribution, in which the phase values are restricted to the defined presentation interval. An absolute combination-phase distribution is generated from the corrected combination-phase distribution, in which the phase values are not restricted to the defined presentation interval.

Abstract: In a magnetic resonance (MR) imaging apparatus and control method therefor, multiple frequency spectra of a material of the examination object are detected using at least one radio-frequency coil of and MR scanner, the coil having a number of coil elements and at least two of the frequency spectra are detected individually detected by respective, different coil elements. A number of resonant frequencies of at least one molecule in the material are established in the number of frequency spectra. Control information is formulated based on the number of resonant frequencies. The magnetic resonance scanner is controlled using the control information.

Abstract: A method for adapting activation parameters used to generate a pulse sequence when activating a magnetic resonance system is provided. The method includes determining stimulation values for the pulse sequence based on predefined activation parameters. The stimulation values represent a stimulation exposure of a patient. Test regions that exhibit stimulation maxima are identified in the pulse sequence, and the identified test regions are tested with respect to compliance with a predefined stimulation limit value.

Abstract: In a method, device and magnetic resonance (MR) system for determining a system frequency in MR imaging, a frequency spectrum of a region under examination is acquired. A cost function (FOM) is determined that encompasses the difference between a parameterized model function having assigned parameters that is to be optimized, and the acquired frequency spectrum. The cost function is subsequently minimized. Furthermore, the parameters of the optimized parameterized model function assigned to the determined minimum are determined and the system frequency is calculated on the basis of the determined parameters.

Abstract: A method is for carrying out an automatic adjustment of an MR system, including a number of receive coils. In such cases, a number of partial spectra in a number of receive coils are measured for an excitation volume of an examination object. The number of partial spectra are evaluated via an algorithm, at least one characteristic value being determined for each partial spectrum and a decision being further made with the aid of the number of characteristic values to determine whether the partial spectra fulfill a quality criterion. Finally, adjustment parameters of the MR system are optimized on the basis of the number of partial spectra.

Abstract: In a magnetic resonance apparatus having a scanner that generates a basic magnetic field in an imaging volume, and an operating method to acquire data from an entirety of a recording volume, wherein the scanner has a global shim coil acting on the entire imaging volume, and a local shim coil acting, with the global shim coil, on a sub-volume containing a region of interest, a first adjustment volume is established that contains the recording volume. A smaller, second adjustment volume is established containing the region of interest, and at most, the sub-volume. Using a field map of the basic magnetic field that covers the first adjustment volume, shim currents are respectively identified for the global shim unit, for homogenizing the first adjustment volume, and for the local shim unit, for homogenizing the second adjustment volume, accounting for the effect of the first shim currents on the second adjustment volume.

Abstract: A method is disclosed for detecting x-rays using an x-ray detector which includes a direct-conversion semiconductor detector element. Additional radiation is supplied to the semiconductor detector element using a radiation source, and the supply of the additional radiation is controlled and/or regulated on the basis of a specified target value. In at least one embodiment, the target value can be specified in a variable manner over time as a sequence of target values. An x-ray detector system is further disclosed, with which the method can be carried out.

Abstract: In a method and magnetic resonance apparatus for determining a shim setting in order to increase a homogeneity of the basic magnetic field of the scanner of the apparatus by operating a shim element, information is obtained concerning the dependence of an induced field of the shim element on a set shim setting. A first field map is recorded and a first shim setting for the shim element is determined based on the first field map. A second field map is recorded while the shim element is driven with the first shim setting. A field induced by the shim element by the first shim setting is determined based on the first field map and the second field map. A second shim setting for the shim element is determined based on the determined induced field and the acquired information.

Abstract: In a method for operating a medical imaging apparatus having multiple sub-systems controlled by a controller in a coordinated manner in order to perform a measurement sequence, a number of first setting parameters are chosen to be constant for a complete measurement sequence, and after a static adjustment, a dynamic adjustment of second setting parameters, which are defined by control signals for the measurement sequence and that can vary while a measurement sequence is being performed, takes place. Base data defining underlying conditions specific to the patient to be imaged are measured for the total imaging volume in a measurement sequence. Reference values for the setting parameters that affect the underlying conditions are saved in association with the base data during the measurement sequence.

Abstract: A direct-converting x-ray radiation detector is disclosed for detecting x-ray radiation, in particular for use in a CT system. In an embodiment, the detector includes a semiconductor material used for detecting the x-ray radiation; at least one collimator; and at least one radiation source, to irradiate the semiconductor material with additional radiation. In at least one embodiment, the at least one collimator includes at least one reflection layer on a side facing the semiconductor material, on which the additional radiation is reflected to the semiconductor material. In another embodiment, a CT system including the direct-converting x-ray radiation detector, and a method for detecting incident x-ray radiation via a direct-converting x-ray radiation detector, in particular for use in a CT system, are disclosed.

Abstract: An x-ray radiation detector is disclosed with an upper side, which faces an x-ray radiation source during operation, and with a semiconductor layer for direct conversion of x-ray radiation into electric measurement signals. In an embodiment, a luminous film is arranged between the upper side and the semiconductor layer, and with the aid of which luminous film, electromagnetic radiation can be coupled into the semiconductor layer.

Abstract: In a method and apparatus for determining at least one patient-specific safety parameter for a medical imaging examination conducted on the patient by a medical imaging device, position data of the patient are acquired by a position data detector while the patient is on a patient-positioning device of the medical imaging apparatus. The acquired position data are evaluated in a processor in order to determine position information of the patient. The patient-specific safety parameter is determined using the position information of the patient.

Abstract: In a magnetic resonance (MR) system and method for determining an MR system frequency for a region to be examined that has multiple materials therein, a first frequency spectrum is acquired by the execution of a first RF excitation sequence. A second frequency spectrum for the region is acquired by radiation of an RF inversion pulse and execution of a second RF excitation sequence, at the point in time at which the relaxation curve of one of the materials has a zero-crossing. Subsequently, echo signals excited by the second RF excitation sequence are read out, from which a frequency spectrum is determined. The first frequency spectrum and the second frequency spectrum are compared. On the basis of the comparison, maxima of the first frequency spectrum are allocated to different materials. The system frequency is determined on the basis of the allocation of the maxima.

Abstract: In a method, device and magnetic resonance (MR) system for determining a system frequency in MR imaging, a frequency spectrum of a region under examination is acquired. A cost function (FOM) is determined that encompasses the difference between a parameterized model function having assigned parameters that is to be optimized, and the acquired frequency spectrum. The cost function is subsequently minimized. Furthermore, the parameters of the optimized parameterized model function assigned to the determined minimum are determined and the system frequency is calculated on the basis of the determined parameters.

Abstract: A direct-converting x-ray radiation detector is disclosed for detecting x-ray radiation, at least including a semiconductor used to detect x-ray radiation and at least one electrode attached to the semiconductor. In an embodiment, the semiconductor and the at least one electrode are electrically conductively connected and the at least one electrode is designed to be transparent and electrically conductive. A CT system is further disclosed, at least including the direct-converting x-ray radiation detector.

Abstract: In a magnetic resonance (MR) imaging apparatus and control method therefor, multiple frequency spectra of a material of the examination object are detected using at least one radio-frequency coil of and MR scanner, the coil having a number of coil elements and at least two of the frequency spectra are detected individually detected by respective, different coil elements. A number of resonant frequencies of at least one molecule in the material are established in the number of frequency spectra. Control information is formulated based on the number of resonant frequencies. The magnetic resonance scanner is controlled using the control information.

Abstract: An x-ray radiation detector is disclosed with an upper side, which faces an x-ray radiation source during operation, and with a semiconductor layer for direct conversion of x-ray radiation into electric measurement signals. In an embodiment, a luminous film is arranged between the upper side and the semiconductor layer, and with the aid of which luminous film, electromagnetic radiation can be coupled into the semiconductor layer.

Abstract: In order to enable efficient calculation of shim settings for a magnetic resonance imaging system, a method for magnetic resonance imaging of an object under investigation using a magnetic resonance device is provided. The method includes acquiring first magnetic resonance image data of the object under investigation using the magnetic resonance device. The method also includes segmenting the first magnetic resonance image data into at least two material classes, calculating a B0 map based on the segmented first magnetic resonance image data and based on susceptibility values of the at least two material classes, and calculating shim settings based on the calculated B0 map. The method also includes acquiring second magnetic resonance image data of the object under investigation using the magnetic resonance device. The acquisition of the second magnetic resonance image data is undertaken using the calculated shim settings.

Abstract: A method and a detector system are disclosed for the photon-counting detection of x-ray radiation with direct conversion detectors. In at least one embodiment of the method, as a function of the existing radiation energy, current and/or voltage pulses which are largely proportional thereto are generated, and the generated current and voltage pulses are counted in the detector when a predetermined current and/or voltage source is exceeded, whereby a threshold is used as a predetermined current and/or voltage threshold, which corresponds to a detection of a photon with an energy which is less than the k-edge of the detector material used.

Abstract: A direct-converting x-ray radiation detector is disclosed for detecting x-ray radiation, at least including a semiconductor used to detect x-ray radiation and at least one electrode attached to the semiconductor. In an embodiment, the semiconductor and the at least one electrode are electrically conductively connected and the at least one electrode is designed to be transparent and electrically conductive. A CT system is further disclosed, at least including the direct-converting x-ray radiation detector.