Patent application number | Description | Published |
20080290281 | Method for data acquisition and/or data evaluation during a functional brains examination with the aid of a combined magnetic resonance/PET unit - A method is disclosed for data acquisition and/or data evaluation during a functional brain examination with the aid of a combined magnetic resonance/PET unit. In at least one embodiment, functional image data of the brain are acquired in at least two activity states with the aid of both modalities. Further, magnetic resonance image data and PET image data are acquired within time windows determined by the activity states, the acquisition mode and/or the image data being synchronized as a function of a timing of stimulations determining the activity states. | 11-27-2008 |
20090005678 | Method for determining and displaying an access corridor to a target area in the brain of a patient - A computer-implemented method is disclosed for determining and displaying an access corridor to a target area in the brain of a patient, as well as an imaging arrangement suited to this. In at least one embodiment, the method includes a) generating a first image of the brain via positron emission tomography, b) discriminating the target area relative to its surroundings via electronic image processing, c) generating a second image of the brain via magnetic resonance imaging while acquiring at least one anatomical structure, d) generating a third image of the brain via an imaging method displaying physiological processes for identifying at least one functional area of the brain that must not be injured in any circumstances, e) determining an access corridor to the target area while omitting the at least one functional area of the brain, and f) generating and displaying a fourth image of the brain in which the target area, the at least one functional area of the brain, the at least one anatomical structure and the access corridor are displayed, wherein steps a) to d) are carried out, one after another in quick succession, in a single frame of reference without repositioning the patient, or are even carried out simultaneously. | 01-01-2009 |
20090018431 | Method and apparatus for imaging functional processes in the brain - A method and an apparatus are disclosed for imaging functional processes in the brain. In order to be able to correlate the results of MEG examinations with anatomical information and metabolic data, a positron emission tomography measurement is recorded in at least one embodiment by at least one radiation detector, a magnetic resonance imaging measurement is recorded by a coil and a radio-frequency antenna device and a magnetoencephalography measurement is recorded by a plurality of magnetic field sensors, the positron emission tomography measurement and the magnetic resonance imaging measurement being substantially undertaken at the same time, so that the records of the positron emission tomography measurement and the magnetic resonance tomography measurement are isocentric. In at least one embodiment, an evaluation apparatus is provided for carrying out a spatial correlation between the magnetoencephalography measurement and the magnetic resonance imaging measurement, so that registration between the magnetoencephalography measurement and the positron emission tomography measurement results. | 01-15-2009 |
20090030304 | Method for detecting a brain region with neurodegenerative change - A computerized method is disclosed for detecting a brain region with neurodegenerative change and also a brain region with vascular change in the brain of a patient and also an imaging arrangement suitable for this. In at least one embodiment, the method includes recording a first data record of the brain via positron emission tomography and a second data record of the brain via magnetic resonance imaging; reconstructing a PET image from the first data record and an MRI image from the second data record; identifying evidence for a brain region with vascular change in the MRI image; segmenting the MRI image into gray matter and white matter; identifying a brain region with neurodegenerative change in the PET image; and superposing the PET image and the segmented MRI image to determine whether the brain region with neurodegenerative change is present in gray matter or in white matter, the recording of the first data record and the second data record being carried out in quick succession without repositioning the patient or is even carried out simultaneously. | 01-29-2009 |
20090033328 | METHOD AND DEVICE FOR OPTIMIZATION OF IMAGING PARAMETERS - In a method and computerized device for determination of imaging parameters for the acquisition of a magnetic resonance image of an examination subject, initial imaging parameters are established, a calculation is made, based on the initial imaging parameters, of signal intensities for tissue types that occur at least in a portion of the examination subject, and the imaging parameters for the acquisition of the magnetic resonance image under are adapted dependent on the calculated signal intensities. | 02-05-2009 |
20090037130 | Method for recording measured data from a patient by taking movements into account, and associated medical device - A method is disclosed for recording measured data from a patient by taking movements into account by use of a medical device designed both for recording motion-related measured data, in particular measured data with a high temporal resolution and/or measured data which can be interpolated with regard to movements, using an imaging method and/or by use of at least one sensor element and for recording nuclear medicine measured data, in particular with a relatively low temporal resolution. In at least one embodiment, the method includes recording nuclear medicine measured data by use of the medical device; simultaneously recording motion-related measured data by use of the medical device; determining at least one motion information item relating to at least one movement of the patient and/or at least one movement inside the body of the patient during the ongoing measured data recording by evaluating at least a portion of the previously recorded motion-related measured data by use of a computational device of the medical device; and carrying out motion correction for at least a portion of the nuclear medicine measured data in real-time by use of the computational device in parallel with recording the measured data depending on the at least one determined motion information item. | 02-05-2009 |
20090041318 | Method for recording measured data of a patient while taking account of movement operations, and an associated medical device - A method is disclosed for recording measured data of a patient while taking account of movement operations by way of a medical device that is designed both for recording movement-related measured data, in particular measured data of high temporal resolution and/or measured data that can be interpolated with regard to movement operations, with the aid of an imaging method and/or by means of at least one sensor element, and also for recording nuclear medicine measured data, in particular of lower temporal resolution. In at least one embodiment, the method includes recording nuclear medicine measured data with the aid of the medical device; simultaneously recording movement-related measured data with the aid of the medical device; determining at least one item of movement information relating to at least one movement operation of the patient and/or in the body of the patient by evaluating at least a portion of the recorded measured data of high temporal resolution on the part of a computing device of the medical device; and adapting at least one item of attenuation correction information available for the computing device and serving for reconstructing the nuclear medicine measured data, doing so as a function of the at least one determined item of movement information. | 02-12-2009 |
20090048507 | Method and apparatus for imaging functional and electrical activities of the brain - A method and an apparatus for imaging functional and electrical activities of the brain are disclosed. In order to allow improved relative positional determination of the epileptogenic focus with reference to the EEG electrodes, a positron emission tomography measurement using at least one radiation detector, and a magnetic resonance imaging measurement using at least one coil for generating a basic magnetic field, at least one gradient coil and a radio-frequency antenna device are undertaken in at least one embodiment. In addition, in at least one embodiment an electroencephalography measurement using a plurality of electrodes for acquiring spatial and temporal changes of the electrical activities of the brain and a computed tomography measurement using at least one x-ray source and at least one x-ray detector are carried out. By way of an evaluation apparatus in at least one embodiment, a spatial correlation between the computed tomography measurement and the magnetic resonance imaging measurement is undertaken, so as to result in registration between the electroencephalography measurement and the positron emission tomography measurement. | 02-19-2009 |
20090121714 | METHOD AND MAGNETIC RESONANCE SYSTEM FOR DETERMINING THE FLIP ANGLE DISTRIBUTION IN A VOLUME OF AN EXAMINATION SUBJECT - In a method for determination of flip angle distributions for various antenna transmission configurations in a magnetic resonance system, magnetic resonance measurements are implemented with the various transmission configurations, with the reception configuration being identical for all implemented magnetic resonance measurements, and all magnetic resonance measurements for the various transmission configurations are implemented with a specific pulse sequence. This pulse sequence is selected such that the total function that describes the dependency of the image signal at a specific location on the flip angle achieved at this location with the radiated radio-frequency field, as well as on further MR-relevant parameters, can be factored into a first sub-function that describes the dependency of the image signal on the achieved flip angle and a second sub-function (Tb) that describes the dependency of the image signal on the further MR-relevant parameters, and such that the functional dependency of the image signal on the achieved flip angle is known. The absolute flip angle distribution is measured for a reference transmission configuration, and the flip angle distributions of the other transmission configurations are then respectively determined on the basis of the absolute flip angle distribution of the reference transmission configuration and on the basis of the ratio of the spatially-dependent image signals of the magnetic resonance measurements of the respective transmission configuration to the corresponding spatially-dependent image signals of the magnetic resonance measurement of the reference transmission configuration. | 05-14-2009 |
20090240379 | OPERATING METHOD FOR A COMPUTER TO DETERMINE OPTIMIZED CONTROL SEQUENCES FOR AN IMAGING MEDICAL SYSTEM - A computer receives information about a measurement sequence to be implemented by a medical imaging system. The computer determines at least one group of preliminary control sequences for power control devices of the medical imaging system so that the power control devices are caused to control (activate) image-influencing emission devices of the imaging medical system corresponding to the determined control sequences, and (insofar as it concerns the control of the image-influencing emission devices) with the measurement sequence to be implemented. The computer determines a load state curve for each group of preliminary control sequences using a model of at least the image-influencing emission devices and the power control devices for these devices using the respective initial load state and the respective control sequence of the image-influencing emission devices and the power control devices. The computer checks for each group whether each load state curve determined for this group remains below a load limit. The computer outputs as final control sequences the preliminary control sequences of one of the groups whose determined load state curves remain below the load limit. | 09-24-2009 |
20090309594 | MAGNETIC RESONANCE IMAGING METHOD AND APPARATUS USING A CIRCULARLY POLARIZED RF RESONATOR DETECTING RIGHT AND LEFT CIRCULARLY POLARIZED COMPONENTS OF MR SIGNALS - In an MR imaging method and apparatus which MR images with improved signal intensity, improved signal-noise ratio, improved contrast and improved image homogeneity can be acquired, the polarization state of the magnetic field of the RF pulses radiated into the measurement subject and of the resonance signals emitted by the measurement subject are distorted by the interaction with electrically-active materials of the measurement subject. In the transmission branch of the RF system the RF pulses emitted by a transmission coil are pre-distorted with regard to their polarization state. The sensitivity of the reception branch is optimized such that it is capable of detecting resonance signals independent of their polarization state. | 12-17-2009 |
20090309596 | MAGNETIC RESONANCE SYSTEM AND OPERATING METHOD WITH COMPENSATION OF SECOND-ORDER MAXWELL TERMS - A magnetic resonance system has a basic magnet system that generates a temporally static, spatially homogeneous basic magnetic field in an examination volume of the magnetic resonance system. At least one radio-frequency system is operated to excite nuclear spins in an examination subject in the examination volume to magnetic resonance, and to detect magnetic resonance signals from the examination subject. An overlay system generates overlay fields in the examination volume. The overlay system has at least one system of the first order and one system of the second order. The system of the first order generates fields that, to a first approximation, exhibit a spatial dependency of the first order. The system of the second order generates fields that, to a first approximation, exhibit a spatial dependency of the second order. A desired gradient and a correction volume are provided to a control device of the magnetic resonance system. The control device weights deviation of the amplitude of the complete field from the desired amplitude with a weighting function that is spatially dependent within the correction volume in order to check whether a minimum condition is satisfied. The control device operates the radio-frequency system with an operating frequency and controls the systems of the first and second order such that the deviation exhibits a spatial dependency of the second order and satisfies the minimum condition within the correction volume. | 12-17-2009 |
20100171498 | MAGNETIC RESONANCE METHOD AND APPARATUS TO REDUCE DISTORTIONS IN DIFFUSION IMAGING - In a method and magnetic resonance (MR) system for correction of image distortions that occur in acquisitions of diffusion-weighted MR images of an examination subject a first adjustment measurement with a first diffusion weighting is implemented, a second adjustment measurement with a second diffusion weighting is implemented and correction parameters to de-skew diffusion-weighted MR images are automatically calculated in a computer on the basis of the two adjustment measurements. One of the two adjustment measurements is implemented with a predetermined diffusion weighting in three orthogonal diffusion directions, and correction parameters are determined for the three orthogonal diffusion directions. | 07-08-2010 |
20100176800 | COIL POSITION DETECTION - A simple position determination is enabled by a device and a method to determine the position of a local coil in a magnetic resonance apparatus, wherein at least one signal emitted by at least one transmission coil is received by the local coil and is evaluated with a position determination device in order to determine the position of the local coil. | 07-15-2010 |
20100271021 | METHOD AND APPARATUS FOR DIFFUSION TENSOR MAGNETIC RESONANCE IMAGING - An apparatus and method for obtaining diffusion weighted magnetic resonance images (DW-MRI) is described. The properties of the diffusion tensor in tissue are measured by applying a diffusion weighting gradient oriented along a plurality of measurement axes. The value of the magnetic field is increased by using as many of the magnetic gradient coils as are effective in contributing the gradient field strength along the axis being. In regions where the magnetic field gradient is increased, the echo time (TE) may be decreased, increasing the signal-to-noise ratio of the measurements. Alternatively, the number of measurements than are averaged to achieve a particular image quality may be decreased, reducing the patient exposure time. | 10-28-2010 |
20100277169 | METHOD AND MAGNETIC RESONANCE SYSTEM FOR DIFFUSION-WEIGHTED ACQUISITION OF MR SIGNALS - In a method for diffusion-weighted acquisition of MR signals with an acquisition sequence that includes a diffusion module with multiple diffusion coding gradients and a readout module with readout gradients to acquire the MR signals, the acquisition sequence is configured to acquire MR signals that correspond to a predetermined signal coherence path. The method includes the acquisition of MR signals with the acquisition sequence, and the diffusion coding gradients are activated with predetermined gradient moments during the acquisition sequence. The gradient moments of the diffusion coding gradients are set such that MR signals that correspond to other coherence paths than the predetermined coherence path are reduced, wherein the adjustment of the gradient moments to achieve a predetermined reduction ensues on the basis of a threshold. | 11-04-2010 |
20100286802 | METHOD TO OPERATE AN IMAGING SYSTEM, AND IMAGING SYSTEM - In an imaging system having a number of subsystems and a control device that controls the subsystems in a coordinated manner to implement a measurement sequence and an operating method therefor, sequence control data that define different functional sub-sequences of the measurement sequence are transmitted to the control device. Different active volumes are associated with the functional sub-sequences. In addition to the sequence control data, active volume position data are provided to the control device that define bearing and extent of the active volumes associated with the different functional sub-sequences. Control signals to implement the measurement sequence for the different subsystems are generated automatically by the control device based on the sequence control data and the active volume position data so that the individual functional sub-sequences are locally optimized at least with regard to a sub-region of their associated active volume. | 11-11-2010 |
20110043204 | MAGNETIC RESONANCE SYSTEM AND METHOD FOR COMPUTERIZED RULE-BASED CONTROL THEREOF - In a magnetic resonance system according to a measurement protocol defined in advance and comprising multiple acquisition parameters, wherein given a non-compliance with at least one limit value (which is automatically established before the beginning of a subject-specific measurement data acquisition)—in particular a SAR limit value and/or a magneto-stimulation limit value and/or a hardware limit value—by the measurement protocol, an adaptation of at least one acquisition parameter ensues using at least one (in particular user-defined) protocol-specific rule for compliance with the limit value, and the measurement data acquisition ensues automatically according to the adapted acquisition parameters. | 02-24-2011 |
20110052031 | METHOD AND MAGNETIC RESONANCE SYSTEM TO CORRECT DISTORTIONS IN IMAGE DATA - In a method for correction of distortions in image data in a diffusion imaging, the image data are acquired with an imaging MRT measurement for a predetermined diffusion weighting and map a predetermined image segment. A diffusion model for the image segment is determined. Output image data are determined for the image segment such that the output image data are essentially free of distortions caused by diffusion weighting. Reference image data are estimated for the predetermined diffusion weighting for the image segment based on the output image data and the diffusion model. The acquired image data are compared with the reference image data and the acquired image data are corrected based on the comparison. | 03-03-2011 |
20110085722 | CORRECTION OF DISTORTIONS IN DIFFUSION-WEIGHTED MAGNETIC RESONANCE IMAGING - In a method and magnetic resonance apparatus for correction of image distortions that occur in acquisition of diffusion-weighted magnetic resonance images of an examination subject, a reference image is acquired without diffusion weighting, a first diffusion-weighted image is acquired for a diffusion direction, a second diffusion-weighted image is acquired for the same diffusion direction, with the acquisition of the second diffusion-weighted image taking place at least with a different diffusion weighting or a different diffusion gradient polarity than the acquisition of the first diffusion-weighted image. Distortion parameters for the correction of image distortions in the acquired diffusion-weighted images are acquired, and the first diffusion-weighted image is deskewed with a first set of deskewing parameters, and the second diffusion-weighted image is deskewed with a second set of deskewing parameters. The first set and second set of deskewing parameters are correlated, and the deskewing parameters are determined by simultaneous minimization of differences between the deskewed first image and the reference image and differentiation between the deskewed second image and the reference image. | 04-14-2011 |
20110187367 | METHOD AND MAGNETIC RESONANCE SYSTEM TO REDUCE DISTORTIONS IN DIFFUSION IMAGING - In a method and magnetic resonance apparatus to reduce distortions in magnetic resonance diffusion imaging, a magnetic resonance data acquisition system is operated to acquire magnetic resonance data in a first measurement with a first diffusion weighting, and to acquire magnetic resonance data in a second measurement with a second, different diffusion weighting. A non-linear, system-specific distortion-correcting function is determined on the basis of system-specific information that is specific to said magnetic resonance data acquisition system. Correction parameters are calculated to correct distortions in subsequently-acquired diffusion-weighted magnetic resonance images, based on the data acquired in the first and second measurements with the system-specific distortion-correcting function applied thereto. The subsequently-acquired diffusion-weighted magnetic resonance images are corrected using the correction parameters to at least reduce distortions therein. | 08-04-2011 |
20110234221 | MAGNETIC RESONANCE METHOD AND APPARATUS TO DETERMINE PHASE CORRECTION PARAMETERS - In a magnetic resonance system and operating method to determine phase correction parameters for a phase correction in MR image data, first and second phase correction data sets are thereby acquired and correlations are calculated between data of the second phase correction data set and data of the first phase correction data set. Phase correction parameters are determined, such as coefficients of a power series that approximates a curve of a phase difference between phase curves of the second and first phase correction data sets. | 09-29-2011 |
20110241679 | MAGNETIC RESONANCE METHOD AND APPARATUS TO REDUCE DISTORTIONS IN DIFFUSION IMAGES - In a method and apparatus to reduce distortions in diffusion imaging, at least one first measurement is implemented with a first diffusion weighting for a number of slices that are spatially separated from one another and at least one second measurement is implemented with a second diffusion weighting for the number of slices that are spatially separated from one another. A deskewing function is determined as are correction parameters to deskew diffusion-weighted magnetic resonance images on the basis of the measurements, so that image information and/or correction parameters of different slices are linked with one another. The diffusion-weighted magnetic resonance images are distortion-corrected on the basis of the deskewing function and the correction parameters. | 10-06-2011 |
20110304334 | MAGNETIC RESONANCE METHOD AND APPARATUS TO CORRECT IMAGE DISTORTIONS IN DIFFUSION-WEIGHTED IMAGING - In a magnetic resonance (MR) apparatus and an operating method for the apparatus, image distortions are corrected that occur in exposures of diffusion-weighted MR images of an examination subject. | 12-15-2011 |
20120068702 | METHOD AND MAGNETIC RESONANCE SYSTEM TO GENERATE A SERIES OF MAGNETIC RESONANCE EXPOSURES - In a magnetic resonance method and apparatus, a series of magnetic resonance exposures of an examination subject is generated by implementing multiple first measurements (data acquisitions) with variation of a measurement parameter from acquisition-to-acquisition, which strongly influences a contrast of the first material type excited in the first measurements, implementing multiple second measurements in which a second material type is essentially selectively imaged that is less contrast-dependent with regard to this measurement parameter in a processor calculating spatial correction values for image data of the first measurements based on spatial differences between image data of different second measurements, and, also in the processor, spatially correcting image data of the first measurements (Di) and/or registration of image data of different first measurements to one another on the basis of the correction values. | 03-22-2012 |
20120217966 | METHOD FOR COMPENSATING FOR EDDY CURRENT FIELDS IN MAGNETIC RESONANCE IMAGES - A method for compensating for eddy current fields in magnetic resonance images acquired using a magnetic resonance apparatus is provided. A global component of the eddy current fields corresponding to a zeroth order and a first order is compensated globally using a change in control parameters of at least one device of the magnetic resonance apparatus that is suitable for compensating for the global components (e.g., a reference oscillator and/or a gradient coil). In order to correct local higher-order eddy current fields in a volume of interest characterized by a prominent point, the residual eddy current fields remaining following compensation of the global component are developed around the point. Correction values for the control parameters are determined from the zeroth- and/or first-order local components of the development and are taken into account in the control of the magnetic resonance apparatus for magnetic resonance image acquisition. | 08-30-2012 |
20130057280 | Magnetic Resonance System and Method for Rephasing Spin Systems in Slices in Slice Multiplexing Measurement Sequences for Magnetic Resonance Imaging - In a method for rephasing a first spin system in a first slice with a first coherence curve and a second spin system of a second slice with a second coherence curve, in the generation of MR images with slice multiplexing, a first RF pulse deflects the spin system of the first slice and a second RF pulse deflects the spin system of the second slice. The beginning of the second RF pulse is time-shifted with respect to the beginning of the first RF pulse by a time period that is shorter than the duration of the first RF pulse. A rephasing correction impresses a correction phase on at least one of the spin systems, and signals of the spin systems are respectively detected. The coherence curves are rephased so detection of the signals occurs simultaneously. | 03-07-2013 |
20130057281 | Magnetic Resonance System and Method for Slice-Selective Detection and Correction of Incorrect Magnetic Resonance Image Data in Slice Multiplexing Measurement Sequences - In a magnetic resonance (MR) method system for slice-selective detection and correction of incorrect magnetic resonance data, a first acquisition sequence is implemented to acquire MR data from a first slice of the examination subject that is associated with a chronologically first coherence curve of the magnetization; a second acquisition sequence is implemented to acquire MR data from a second slice of the examination subject that is associated with a chronologically second coherence curve of the magnetization. In slice multiplexing measurement sequences that are characterized by the simultaneous use of the transverse magnetization of the first and second slice within the first and second acquisition sequences slice-selective errors can be detected and corrections made. | 03-07-2013 |
20130063144 | MAGNETIC RESONANCE METHOD AND APPARATUS TO REDUCE ARTIFACTS IN DIFFUSION-WEIGHTED IMAGING - In a method and system for diffusion-weighted acquisition of MR signals with an image acquisition sequence that has multiple diffusion coding gradients and readout gradients to read out the MR signals, MR signal portions are generated with a desired signal coherence path and MR signal portions are generated with unwanted signal coherence paths, with predominantly the MR signal portions with the desired signal coherence path being acquired by the readout gradients by activating dephasing gradients that reduce the acquisition of MR signal portions with unwanted coherence paths. The dephasing gradients are determined under consideration of the diffusion gradients that are used and under consideration of the unwanted signal coherence paths, so that each has a dephasing gradient moment for each unwanted signal coherence path that is greater than a threshold. | 03-14-2013 |
20130088228 | METHOD AND APPARATUS FOR MAGNETIC RESONANCE IMAGING - In a method and apparatus for magnetic resonance (MR) imaging, a magnetization of nuclear spins in a subject is prepared in multiple preparation modules of an acquisition sequence. MR signals are acquired with at least one imaging module of the sequence. Spoiler gradient fields are generated in the multiple preparation modules in order to affect a transverse magnetization of the spins. The spoiler gradient fields that are applied in at least two different preparation modules are spatially varied along different directions. Spoiler gradient moments of the spoiler gradient fields are selected so that, for at least one of three orthogonal spatial directions, a weighted sum of the spoiler gradient moments that are applied along this spatial direction satisfies a threshold condition. | 04-11-2013 |
20130090776 | OPERATING METHOD FOR A COMPUTER TO DETERMINE OPTIMIZED CONTROL SEQUENCES FOR AN IMAGING MEDICAL SYSTEM - A computer is supplied with information about a measurement sequence to be implemented by a medical imaging system, and determines at least one group of preliminary control sequences for power supply devices of the medical imaging system so that the power control devices are caused to control image-influencing emission devices of the imaging medical system corresponding to the control sequences. Using a model of the image-influencing emission devices and their respective power control devices, and their respective initial load state, the computer determines whether a load state curve for those devices is below a load limit, and emits a final control sequence for those devices that are determined to be below the limit. | 04-11-2013 |
20130127462 | Method for Operating a Receiving Device for Magnetic Resonance Image Signals of a Body - A receiving device for magnetic resonance (MR) image signals of a body is operated in an MR system such that for at least one coil element of the receiving device, a space domain, in which a spatial sensitivity of the coil element satisfies a predetermined criterion, is determined. A center frequency and a bandwidth of the MR image signal radiated by the body in the space domain are determined for the space domain. A receive path disposed downstream of the coil element is parameterized for operation at the determined center frequency and with the determined bandwidth. | 05-23-2013 |
20130249550 | METHOD AND MAGNETIC RESONANCE SYSTEM TO ACQUIRE MR DATA IN A PREDETERMINED VOLUME SEGMENT OF AN EXAMINATION SUBJECT - In a method and a magnetic resonance (MR) system, a marked area is determined that demarcates a predetermined volume segment of the subject relative to the regions adjacent thereto. Nuclei in the predetermined volume segment are excited, or nuclei in a region adjacent thereto are saturated with an RF excitation pulse at the same time a magnetic field gradient is activated. The center frequency of a frequency range of the RF excitation pulse and the direction of the magnetic field gradient are adjusted dependent on resonant frequencies of substances present within the predetermined volume segment in order, starting from the predetermined volume segment to shift an actual excitation volume segment excited by the RF excitation pulse toward the marked area, or to shift a saturation volume saturated by the RF excitation pulse away from the marked area. MR data are then acquired from the predetermined volume segment. | 09-26-2013 |
20130257426 | Activating a Magnetic Resonance System - A method for activating a magnetic resonance system having a transmit antenna arrangement is provided. The transmit antenna arrangement includes a plurality of independent high-frequency transmit channels with a respectively assigned transmit antenna. Each high-frequency transmit channel has a controllable oscillator. The individual high-frequency transmit channels are activated with independent transmit pulses, and a frequency of the controllable oscillators is controlled independently. At least two of the controllable oscillators therefore oscillate in different frequencies. | 10-03-2013 |
20130285654 | METHOD AND APPARATUS TO GENERATE MAGNETIC RESONANCE IMAGES - In a method and apparatus to generate a magnetic resonance (MR) image in a volume of interest of an examination subject, the magnetization is excited in an additional volume in the subject by at least one RF pulse, in order to achieve a desired magnetization in the volume of interest. The additional excitation volume differs at least partially from the volume of interest. For this purpose, at least one MR overview image of the examination subject is analyzed automatically to determine a position of at least one anatomical structure of the examination subject, from which the volume of interest is automatically determined. The additional excitation volume is automatically determined using the position of the at least one anatomical structure. The MR image in the volume of interest is acquired with excitation of the magnetization in the automatically determined additional excitation volume. | 10-31-2013 |
20130285656 | SLICE-SPECIFIC PHASE CORRECTION IN SLICE MULTIPLEXING - In a method to correct a signal phase in the acquisition of MR signals of an examination subject in a slice multiplexing method, in which MR signals from at least two different slices of the examination subject are detected simultaneously in the acquisition of the MR signals, a linear correction phase in the slice selection direction is determined for each of the at least two slices. An RF excitation pulse with a slice-specific frequency is radiated in each of the at least two different slices. A slice selection gradient is activated during a slice selection time period, during which the different RF excitation pulses are radiated in the at least two different slices, and the slice selection time period has a middle point in time in the middle of the slice selection time period, and the different RF excitation pulses temporally overlap for the at least two different slices. A time offset of the RF excitation pulse relative to the middle point in time for each of the RF excitation pulses is determined, such that a slice-specific correction gradient moment in the slice selection direction that corresponds to the linear correction phase of the respective slice acts on the magnetization of the respective slice. | 10-31-2013 |
20140091797 | METHOD AND MAGNETIC RESONANCE SYSTEM TO ACQUIRE MR DATA WITH DIFFUSION INFORMATION - In the acquisition of MR data with diffusion information nuclear spins in a volume segment are excited with radiation of a diffusion coding module and a subsequent diffusion decoding module, and at least one RF pulse is radiated after the excitation, and the MR data are read out. At least one of a time period that defines a time interval between a point in time at which the spin echo condition is satisfied, and the echo time, a first time interval that defines a minimum time interval between the end of the diffusion coding module and the start of the diffusion decoding module, and a second time interval that defines a minimum time interval between the end of the excitation module, and the start of the diffusion coding module, and a third time interval that defines a minimum time interval between the end of the diffusion coding module and the start of the readout of the MR data, is set. | 04-03-2014 |
20140133725 | METHOD AND MAGNETIC RESONANCE DEVICE FOR THE AUTOMATED CLASSIFICATION OF AN IMAGE PROPERTY OF A MAGNETIC RESONANCE IMAGE - A method is disclosed for the automated classification of an image property of a magnetic resonance image. In an embodiment, the method includes determining at least the parameters T1, T2 and proton density of at least two tissues imaged in the magnetic resonance image or prespecifying at least two sets of at least these parameters; calculating the signal intensity in the center of the k-space for each imaged tissue or each set of parameters; and classifying the image property as a function of the calculated signal intensities. A magnetic resonance device is also disclosed. | 05-15-2014 |
20140278195 | OPERATING METHOD FOR A COMPUTER TO DETERMINE AN OPTIMIZED MEASUREMENT SEQUENCE FOR A MEDICAL IMAGING SYSTEM - In a method for operating a medical imaging system and a medical imaging system operating according to such a method, a measurement sequence is divided into a number of partial sequences, with each of the partial sequences resulting in a loading of at least one of these system components when the measurement sequence is executed. The partial sequences are evaluated, in terms of their number and duration, using a computerized model in order to determine whether a load limit for the at least one of the system components is exceeded. If so, the number or duration of the partial sequences is modified, and a check using the computer model is again implemented. A number or respective duration of the partial sequences that results in the load limit not being exceeded is then used as a final output in order to operate the medical imaging system. | 09-18-2014 |
20150038830 | MAGNETIC RESONANCE DEVICE - A magnetic resonance device with at least one main field magnet and at least one gradient coil is provided. The magnetic resonance device provides more free space for the patient and treatment providers; the magnetic resonance device has at least one main field magnet, which is provided to generate a magnet volume. The magnet volume has an imaging region, which is displaced from the center of the main field magnet along a longitudinal axis defined by the main field magnet. The magnetic resonance device also has a gradient coil. In the direction of the longitudinal axis defined by the main field magnet, the gradient coil has a first side facing away from the main field magnet and a second side facing the main field magnet. The gradient coil has a cross-section with a larger area on the first side facing away than on the second facing side. The gradient coil is provided to generate variable magnetic gradient fields, the gradient fields being provided for magnetic resonance imaging in the imaging region of the magnet volume. | 02-05-2015 |
20150042336 | MR IMAGING WITH SIGNAL SUPPRESSION OF A SPIN SERIES - In a magnetic resonance measurement sequence, an inversion pulse is applied that acts on a longitudinal magnetization of a first spin species and a second spin species, for example on a water portion and a fat portion. An excitation pulse is applied after a predetermined time period. At least one manipulation pulse is subsequently applied, respectively with associated gradient pulse. | 02-12-2015 |