Abstract: A system for magnetic resonance imaging an object is provided. The system includes a plurality of coil element groupings disposed within one or more RF coils, and a controller. The controller is operative to receive MR data from the object via the one or more RF coils, determine a g-factor for each of the coil element groupings of the plurality based at least in part on the MR data, and select a coil element grouping of the plurality based at least in part on the g-factors.

Abstract: A method of magnetic resonance imaging includes executing an imaging sequence, in response to the imaging sequence, acquiring magnetic resonance data, entering the acquired magnetic resonance data in k-space in a memory along a predetermined k-space trajectory, and modifying the k-space trajectory during acquisition of the magnetic resonance data.

Abstract: A method of magnetic resonance imaging includes executing an imaging sequence, in response to the imaging sequence, acquiring magnetic resonance data, entering the acquired magnetic resonance data in k-space in a memory along a predetermined k-space trajectory, and modifying the k-space trajectory during acquisition of the magnetic resonance data.

Abstract: A system for training a linearization compensation model includes a tone generator for providing at least two different RF tones, receiver path components for processing the RF tones, an analog-to-digital converter for converting the processed RF tones into digital signals, and a processor for using the digital signals to generate the linearization error compensation model. The resulting compensation model is particularly useful in a linearization system which includes a receiver for measuring a signal, an electro-optical modulator configured for converting the measured signal to an optical signal, an optical-electrical detector configured for converting the optical signal to an analog electrical signal, an analog-to-digital converter for converting the analog electrical signal into a digital signal with the processor being used for removing linearization errors from the digital signal.

Abstract: An integrated, multi-modality imaging technique is disclosed. The embodiment described combines a split-magnet MRI system with a digital x-ray system. The two systems are employed together to generate images of a subject in accordance with their individual physics and imaging characteristics. The images may be displaced in real time, such as during a surgical intervention. The images may be registered with one another and combined to form a composite image in which tissues or objects difficult to image in one modality are visible. By appropriately selecting the position of an x-ray source and detector, and by programming a desired corresponding slice for MRI imaging, useful combined images may be obtained and displayed.

Abstract: A radio frequency space cooling system (11) for a magnetic resonance imager system (10) includes a thermal energy transfer device (78). The energy transfer device (78) reduces the temperature of a cooling fluid (86) within the cooling system (11). A cooling element (82) is coupled to the energy transfer device (78) and extends along a patient bore (15) between a radio frequency shield (22) and a radio frequency coil (20) of the magnetic resonance imager system (10). The cooling element (82) has a channel (90) for passage of the cooling fluid (86).

Abstract: A method of operating a magnetic resonance imaging system having a first coil and a second coil to achieve an imaging volume includes, in a first mode, achieving the imaging volume by using a sum field from both of the coils, and, in a second mode, achieving the imaging volume by using a difference field from both of the coils.

Abstract: The present invention is directed to a method and apparatus that hierarchically prioritizes scan parameters of a medical imaging application on a per scan basis. The present invention prioritizes the scan parameters to define a dependence relationship for each scan parameter. By defining this relationship between the scan parameters on a per scan session, the present invention can notify a user of an invalid scan parameter input. A graphical user interface is provided to facilitate entry and/or modification of scan parameter values and is likewise configured to notify the user of parameter invalidity.

Abstract: A magnetic resonant imaging apparatus having an operator console with input and output devices, a computer system for acquiring, processing and storing MRI images, and a system control device for generating and acquiring MRI image data. The magnetic resonant imaging apparatus comprises a table and a magnet assembly. An embodiment of the magnetic resonant imaging apparatus provides for the magnetic assembly to be positioned below the table. Another examplary embodiment of the magnetic resonant imaging apparatus provides for the magnetic assembly to be positioned at one end of the table and at the side of a table with the magnet assembly in a perpendicular aspect with respect to the table. The magnet assembly can be positioned with a partition member disposed between the table and the magnet assembly.

Abstract: A magnetic resonance imaging method and device (1) allow for automatic quantitative motion evaluation of a part of an object (4). The pulse and gradient sequence (tsq1, tsq2), which achieves a high contrast tagging grid, is a stimulated echo based tagging sequence, the tagging section (TAG) being applied before the imaging section (img) or being integrated (G.sub.9, G.sub.10) in the imaging section (img).

Abstract: A magnetic resonance imaging method and device include a processor and a demodulator including a signal sampling device which provide automatic quantitative motion evaluation of a part of an object. Pulse and gradient sequences (tsq) are applied in pairs with spatially differing tagging patterns, images corresponding to the pairs being subtracted so as to form a tagged image. The motion is monitored by scanning of the tagging pattern in the tagged image which permits improved motion evaluation.

Abstract: A sequence acts--preferably several times--upon an examination region, which sequence comprises two frequency-selective high-frequency pulses not exciting the water component, between which a 180.degree. high-frequency pulse is present. Such a sequence can be more insensitive to imperfections of the 180.degree. pulse in that the second frequency-selective high-frequency pulse is followed by a further frequency-selective high-frequency pulse not exciting the water component and in that between the second frequency-selective high frequency pulse and the further high-frequency pulse as well as after the further high-frequency pulse a magnetic gradient field is switched on and off in such a manner that the time integrals across this gradient field before and after the further high-frequency pulse are equal to each other.

Abstract: Two-dimensional nuclear magnetic resonance spectroscopy with a frequently repeated sequence comprises four high-frequency pulses and acting together with a homogeneous stationary magnetic field upon an examination area, which sequence contains two 180.degree. pulses, halfway between which a third pulse is located. The pulse of the sequence are preceded by a first pulse, whose distance from the second pulse, which is equal to or larger than the relative distance of the other pulses, is varied during the repetition of the sequence. This method is particularly suitable for in vivo examinations of the human body in that during three of the four pulses magnetic gradient fields are operative, whose gradients extend mutually perpendicular to each other, and before and after the third high-frequency pulse a magnetic gradient field is operative having such a duration and such a gradient that the time integral across this field has the same value before the third pulse as after the third pulse.

Abstract: A plurality of sequences act on an examination zone in the presence of a uniform, steady magnetic field, each of the sequences comprising at least three RF pulses which are preferably formed as 90.degree. pulses, applying between the second and the third RF pulse and after the third RF pulse magnetic gradient fields (G.sub.x) having an amplitude and a duration such that spin resonance signals occurring after the third RF pulse are determined exclusively by double quantum coherence. Thus, spatial and spectral determination of a lactate component is simultaneously possible when it is ensured that at least one magnetic gradient field is applied between or after the three RF pulses and when the time integral over at least one of these gradient fields is varied during repetition of the sequences, the second RF pulse (HF.sub.2) being frequency selective to reduce the lipid component (L.sub.1) near the lactate component (M.sub.1) so that the nuclear magnetization of the component (M.sub.

Abstract: A magnetic resonance spectroscopy method, and apparatus for performing the method, where a plurality of sequences act on an examination zone in the presence of a uniform, steady magnetic field, each sequence comprising at least three RF pulses, the distance between the first two RF pulses being equal to the reciprocal value of twice the scalar coupling constant J, between and after the pulses there being applied magnetic gradient fields having an amplitude and a duration such that the spin resonance signals occurring after the third RF pulse are determined exclusively by double quantum coherence. In order to suppress the fat component situated in the immediate vicinity of the lactate component of lower Larmor frequency, the lipid component at the area of the lactate component is reduced by making the second and/or the third RF pulse frequency-selective so that it acts as an 90.degree. pulse for the component coupled to the lactate component and as a 0.degree. pulse or 180.degree.

Abstract: An rf generator for magnetic resonance imaging apparatus including a modulator in which a carrier is modulated with an envelope signal, and a transmitter stage which is connected subsequent to the modulator generator in which the implementation of the modulating signal enables the expenditure for the transmitter stage be substantially reduced in that the modulator comprises a first modulator section in which the envelope signal is converted into a series of equally long digital pulses whose density corresponds to the amplitude of the envelope signal, in that k different kinds of pulses are provided, in that during each pulse of a given kind the carrier is always switched on with a given phase position which deviates from the phase positions of the carrier which are associated with the pulses of the other kinds by 360.degree./k or an integer multiple thereof, and in that the resultant pulse-wise switched, preferably square-wave carrier acts as a switching signal for the transmitter stage.