Abstract: An MR imaging system uses multiple RF coils for acquiring corresponding multiple image data sets of a slice or volume of patient anatomy. An image data processor comprises at least one processing device conditioned for, deriving a first set of weights for weighted combination of k-space data of the multiple image data sets for generating a calibration data set comprising a subset of k-space data of composite image data representing the multiple image data sets. The image data processor uses the calibration data set in generating a first MR image data set, deriving the parameters of a probability distribution in response to the first set of weights and the first MR image data set and deriving a second set of weights and second MR image data set together using the probability distribution.

Abstract: In imaging using 2-dimensional selective excitation pulses, regardless of applications thereof, a technique for obtaining a high quality image is provided. In the technique, a 2-dimensional selective excitation sequence is carried out while changing a coefficient for determining the cylinder diameter of a region excited by the 2-dimensional selective excitation sequence and a time difference for determining an offset position. The obtained excitation region and a desired region are compared with each other, and the coefficient and time difference with which the obtained excitation region and the desired region match each other are determined to be the optimum ones. The determination processing may be performed as an initial adjustment, may be performed according to need in each imaging, or may be performed on a per-application basis.

Abstract: In multi-echo multi-contrast imaging, the image quality is improved by suppressing an increase in imaging time. In order to do so, the arrangement order of echo signals that form an echo train and k space filled with each echo signal are determined such that the continuity of the echo arrangement is maintained while sharing an echo signal between contrasts in multi-echo multi-contrast imaging. Echo trains that perform echo sharing are arranged in non-oscillatory centric view ordering (NOCO). In addition, the starting point of echo sharing of one echo train is connected to the same position of another echo train. When some discontinuous regions are present, the discontinuous regions may be corrected using continuous data of regions symmetrical thereto on the k space.

Abstract: Disclosed are a magnetic resonance imaging apparatus and an RF pulse control method wherein an RF pulse sequence in a start-up sequence is set as a monotonically increasing flip angle with offset, in order to reduce ghosts, blurring, and other artifacts during measurement in a transient state. For example, the sum of two adjacent consecutive terms in a monotonically increasing sequence is set as the flip angle. Specifically, the number of RF pulses in the RF pulse sequence and the flip angle for the RF pulses in an SSFP sequence are set, and the monotonically increasing flip angle with offset is found, based on the set number of RF pulses in the RF pulse sequence and the flip angle for the RF pulses in the SSFP sequence, and used as the RF pulse sequence.

Abstract: A method for performing multi-slice MR Elastography on an anatomical region of interest associated with a patient includes inducing shear waves at a shear wave frequency value (e.g., between 25-500 Hz) in the anatomical region of interest using an external driver. Next, the anatomical region of interest is imaged during a single patient breath-hold using an MRI acquisition process. Following the MRI acquisition process(es), phase images of the anatomical region of interest are generated based on an acquired RF signal. These phase images may then be processed (e.g., using an inversion algorithm) to generate one or more quantitative images depicting stiffness of the anatomical region of interest. In some embodiments, a wave image is also generated showing propagation of the plurality of shear waves through the anatomical region of interest based on the phase images.

Abstract: A system for parallel image processing in MR imaging comprises multiple MR imaging RF coils for individually receiving MR imaging data representing a slice of patient anatomy. An MR imaging system uses the multiple RF coils for acquiring corresponding multiple image data sets of the slice. An image data processor comprises at least one processing device conditioned for, deriving a first set of weights for generating a calibration data set comprising a subset of k-space data of composite image data representing the multiple image data sets. The at least one processing device uses the calibration data set in generating a first MR image data set, deriving a second set of weights using the calibration data set and the generated first MR image data set and uses the second set of weights in generating a second MR image data set representing a single image having a reduced set of data components relative to the first composite MR image data set.

Abstract: In a multi-echo measurement sequence with the goal of optimizing the spatial resolution given predetermined time difference between successive gradient echoes, gradient pulse parameters are set depending on a defined ratio between a predetermined time difference between echo times and a quotient of a predetermined maximum gradient pulse amplitude and a predetermined maximum gradient pulse rate-of-change.

Abstract: A method and a control sequence determination device for the determination of a magnetic resonance system activation sequence including at least one high-frequency pulse sequence to be transmitted by a magnetic resonance system are provided. A current B0 map and optionally a target magnetization are acquired. In addition, a k-space trajectory type is determined. An error density is calculated in a k-space based on the current B0 map and optionally based on the target magnetization using an analytic function. This analytic function defines an error density in the k-space as a function of the current B0 map and optionally the target magnetization. Taking account of the error density in the k-space, a k-space trajectory of the specified k-space trajectory type is determined. The high-frequency pulse sequence is determined for the k-space trajectory in an HF pulse optimization process.

Abstract: A method is proposed for the simultaneous optimization of an arbitrary number of electromagnetic pulses, which act in a cooperative way, or mutually compensate each other's errors. The method generally relates to pulses which can have improved properties when cooperating with each other compared to single pulses. In experiments with several scans, undesired signal contributions can be suppressed by COOP pulses, which complements and generalizes the concept of phase cycling. COOP pulses can also be used in individual scans. COOP pulses can be optimized efficiently with the aid of an extended version of the optimal-control-theory-based gradient ascent pulse engineering (GRAPE) algorithm. The advantage of the COOP pulse method is demonstrated theoretically and experimentally for broadband and band-selective excitation and saturation pulses.

Abstract: In one embodiment, an RF coil device includes a base board, a belt member, a first coil element, a second coil element inside the base board, and a connecting unit. Both ends of the belt member are respectively connected to mutually separated places on the base board, so that the center part of the belt member is located on the anterior surface of the base board. The belt member is curved to form airspace between the center part thereof and the anterior surface for letting an arm pass through in interdigitation state. The first coil element includes first and second partial coils inside the belt member, and becomes a loop coil element by their connection. The connecting unit detachably connects the base board to the belt member, and mutually connects the first and second partial coils in the interdigitation state.

Abstract: A method for the control of a magnetic resonance system is provided. In a test phase before a magnetic resonance measurement, a test high-frequency pulse with several parallel individual high-frequency pulses is transmitted with a transmitter antenna arrangement over various different high-frequency transmitter channels. At lower transmitter power, the test high-frequency pulse generates essentially the same field distribution as an excitation high-frequency pulse to be transmitted during a subsequent magnetic resonance measurement. A high-frequency field generated by this test high-frequency pulse is measured in at least one area of a local pulse arrangement, and on the basis of the high-frequency field measured, a high-frequency field value that is to be anticipated at the local coil arrangement during the subsequent magnetic resonance measurement is determined.

Abstract: The invention relates to a digital amplifier for providing a desired electrical output power, the amplifier comprising a power source (100) for generating the electrical output power, the amplifier further comprising: a digital input adapted for receiving a digital input signal (112), the digital input signal (112) representing the desired electrical output power level, a reference power generator (124) for generating an analog reference power controlled by the digital input signal (112), a power measurement component (142; 128) adapted for measuring the power differential between the electrical output power provided by the power source (100) and the analog reference power, an analog-to-digital converter (130) adapted for converting the power differential into a digital power differential value (132), a combiner adapted for providing a combined digital signal (136) by adding the digital power differential value (132) to the digital value input to the reference power generator (124) for generating the analog r

Abstract: A method of correcting warping of an acquired image in an MRI system, caused by non-linearities in gradient field profiles of gradient coils is set forth, comprising a) constructing a computer model representing conducting pathways for each gradient coil in said MRI system; b) calculating a predicted magnetic field at each point in space for each said gradient coil in said model; c) measuring actual magnetic field at each point in space for each said gradient coil in said MRI system; d) verifying accuracy of said model by comparing said predicted magnetic field to said actual magnetic field at each said point in space and in the event said model is not accurate then repeating a)-d), and in the event said model is accurate then; constructing a distortion map for mapping coordinates in real space to coordinates in warped space of said acquired image based on deviations of said predicted magnetic field from linearity; and unwarping said warping of the acquired image using said distortion map.

Abstract: Exemplary embodiments are directed to estimating an electrical property of tissue using Magnetic Resonance (MR) images. In exemplary embodiments, complex MR images of a target tissue are obtained. An estimated value of an electrical property of the target tissue is determined based on complex values of the pixels in the complex MR images. The complex values are proportional to the product of the transmit radio frequency magnetic field and the receive RF magnetic field.

Abstract: A system for inductively communicating signals in a magnetic resonance imaging system is presented. The system includes first array of primary coils configured to acquire data from a patient positioned on a patient cradle. Furthermore, the system includes a second array of secondary coils operatively coupled to the first array of primary coils. Moreover, the system includes a third array of tertiary coils disposed at a determined distance from the second array of secondary coils. In addition, the system includes a tuning unit operatively coupled to the third array of tertiary coils by a cable having a quarter-wave electrical wavelength and configured to control the first array of primary coils through impedance transformation, where the second array of secondary coils is configured to inductively communicate the acquired data to the third array of tertiary coils.

Abstract: A magnetic resonance coil for transmitting and/or receiving magnetic resonance signals is provided. The magnetic resonance coil includes at least two overlapping coil elements. Coil conductors of the at least two overlapping coil elements intersect in intersection regions and are arranged on a support. Mutually overlapping coil elements of the at least two overlapping coil elements are arranged on different sides of the support. The support is formed from at least three layers of a support material. A cavity that is filled with air or a filler material, the dielectric constant of the filler material being lower than the dielectric constant of the support material, is provided in the intersection regions in a middle layer of the at least three layers.

Abstract: An automated shim power supply system and associated methods for calibrating the magnetic field in magnetic resonance imaging devices by precisely adjusting the currents in shim coils. An automated shim power supply system sets, monitors, and corrects programmable power supply outputs to ensure stable output currents to shim coils with milliampere precision. Accompanying methods include iteratively measuring primary field flux and setting shim coil currents to correct inhomogeneities to within OEM specifications.

Abstract: An NMR spectrometer and method in the following three steps are performed. (1) An external magnetic field is set to H0+?H (where 4H>0). When the detection coil made of the superconducting material is still in a normal state, a magnetic field stronger than the ultimate target static magnetic field strength H0 by ?H is applied to the detection coil. (2) The detection coil made of the superconducting material is cooled down to T0 lower than its critical temperature Tc to bring the coil into a superconducting state while the external magnetic field H0+?H is applied to the detection coil. (3) The external magnetic field is lowered from H0+?H to H0 such that the applied external magnetic field is decreased by ?H while the detection coil is kept in the superconducting state.

Abstract: Monitoring cell (100) for performing an NMR measurement of a reaction fluid. The monitoring cell (100) has a hollow NMR sample probe (110) for receiving the reaction fluid. Inlet and outlet transport capillaries (112, 123) transport the reaction fluid to and from the sample probe (110). A feed line (306) and return line transport a temperature control fluid to and from the monitoring cell (100). An adapter head (108) couples the transport capillaries (112, 123) to the sample probe (110) and removably connects the sample probe (110) to an adapter section (106). The transport capillaries (112, 123) are positioned within the feed line (306) in parallel to one another. The feed and the return lines (306, 358) are attached to the adapter section (106) such that a reversal of the temperature control fluid stream occurs in the adapter section (106).

Abstract: In a method to determine the actual flip angle in magnetic resonance tomography with continuous table feed, at least one echo signal is generated by a pulse sequence from which an actual flip angle is produced with at least one RF pulse of the sequence, and a gradient scheme is used in the direction of the continuous travel of the examination subject, the gradient scheme being designed such that its first moment disappears at the points in time of each echo signals used for the determination of the flip angle. Such a pulse sequence is also used in a method for adjustment of the transmitter voltage for RF pulses given continuous travel of the examination subject in a magnetic resonance apparatus.