Abstract: In accordance with various embodiments, a radio frequency (RF) coil array for use in a magnetic resonance imaging (MRI) system includes at least first and second RF coils. Each of the RF coils have a main body loop configured to at least one of transmit or receive RF energy at an operating imaging frequency in connection with acquiring MRI image data for an MRI system. The RF coil array also includes first and second cables configured to electrically couple the first and second RF coils, respectively, to a system interface. The RF coil array also includes a common ground connection between the first and second cables. The common ground connection is selectively positioned at a grounding point along lengths of the first and second cables to form a ground loop having a select self-resonance frequency (SRF) that differs from the imaging frequency of the MRI system.

Abstract: Example systems, apparatus, circuits, and other embodiments described herein concern parallel transmission in MRI. One example apparatus includes at least two enhanced mode gallium nitride (eGaN) based field effect transistors (FETs) that are connected by a coil that includes an LC (inductance-capacitance) leg. The apparatus includes a controller that inputs a signal to the eGaN FETs to control the production of an output analog radio frequency (RF) signal. The LC leg selectively alters the output analog RF signal. The analog RF signal is used in parallel magnetic resonance imaging (MRI) transmission. One embodiment provides an MRI transmit coil with switched-mode current-source amplification provided by a gallium nitride FET.

Abstract: NMR measurements are made along with acoustic measurements using one tool. The antenna of the NMR sensor is used to create acoustic signals. Interference between the acoustic and NMR measurements is avoided due to the frequency difference, and by having the acoustic excitation during a wait time of the NMR pulse sequence.

Abstract: An MRI apparatus includes a magnetic resonance imaging (MRI) system having a plurality of gradient coils positioned about a bore of a magnet, an RF coil assembly having at least a first port and a second port, an RF transceiver system having a pulse module and configured to transmit RF signals to the first port and the second port, and a computer programmed to drive the RF coil assembly in quadrature through the at least first port and the second port, measure a B1 field using at least one flux probe at two or more angular orientations within the RF coil assembly, and characterize and optimize performance of the MRI system based on the measurements of the B1 field.

Abstract: In a method and a pulse sequence determination device to determine a pulse sequence for a magnetic resonance system, control protocol parameter values are initially acquired. A determination of k-space trajectory node points within k-space then takes place in a processor on the basis of the control protocol parameter values. The determination of the pulse sequence then takes place on the basis of the k-space trajectory node points. A method for operating a magnetic resonance system uses such a pulse sequence, and a magnetic resonance system embodies such a pulse sequence determination device.

Abstract: In a method and a pulse sequence optimization device to determine a pulse sequence for a magnetic resonance system, a pulse sequence is selected for optimization that includes a number of radio-frequency pulses and a number of gradient pulses chronologically coordinated therewith. An automatic analysis of the pulse sequence takes place to identify fixed point/time periods in the pulse sequence that are to be left unmodified, and modifiable time intervals in the pulse sequence that may be optimized. An automatic optimization of gradient pulses in the modifiable time intervals takes place according to a predetermined optimization criterion, while keeping the length of modifiable time intervals constant.

Abstract: The temperature of an MRI gradient magnetic field coil unit is measured at least two times. Shift data indicating a center magnetic resonance frequency of a hydrogen atom in response to variation of the gradient coil temperature is stored in advance. Estimated shift of the center frequency based on the measurement result is determined and the center frequency of an RF NMR excitation pulse is corrected based on the estimated shift.

Abstract: In a method to control a magnetic resonance device for image acquisition in at least one slice, the magnetic resonance device has a radio-frequency antenna with multiple transmission channels. At least one slice deviates from a cuboid shape and/or that is roughly adapted to a target volume of interest that is to be acquired, and/or at least one saturation volume adapted to a shape in a subject to be acquired, are defined automatically and/or manually via a user interface. The selection of possible slices and/or saturation volumes is limited automatically under consideration of the technical embodiment of the radio-frequency antenna. The image acquisition takes place in the selected slice and/or under consideration of the saturation volume.

Abstract: In a magnetic resonance marking system marking a flowing medium in a marking region, as well as in a magnetic resonance system with such a magnetic resonance marking system, a method to control a magnetic resonance marking system, and a method to generate magnetic resonance exposures, a radio-frequency transmission device generates marking radio-frequency signals, and a marking radio-frequency transmission coil emits the marking radio-frequency signals in the marking region. A magnetic field determination device determines a magnetic field strength in the marking region, and a control unit derives a marking transmission frequency from the determined magnetic field strength and to control the radio-frequency transmission device so that marking radio-frequency signals at the derived marking transmission frequency are emitted by the marking radio-frequency transmission coil.

Abstract: Example systems, apparatus, and circuits described herein concern a multi-turn transmit surface coil used in parallel transmission in high field MRI. One example apparatus includes a balun network that produces out-of-phase signals that are amplified to drive current-mode class-D (CMCD) field effect transistors (FETs) that are connected by a coil that includes an LC (inductance-capacitance) leg. The LC leg selectively alters the output analog RF signal and the analog RF signal is used in high field parallel magnetic resonance imaging (MRI) transmission. The multi-turn transmit surface coil produces an improved (e.g., stronger) B1 field without increasing heat dissipation.

Abstract: Methods and systems for designing excitation pulses for magnetic resonance imaging are provided. One method includes parameterizing spin-domain rotation parameters to define parameterized variables and defining a constrained optimization problem based on the parameterized variables. The method also includes solving the constrained optimization problem and generating parameters for the RF pulses based on the solved problem, wherein the RF pulses are one of multidimensional RF pulses on non-constant gradient trajectories or one dimensional RF pulses on non-constant gradient trajectories.

Abstract: A method of preparing a multi-channel coil, in particular for magnetic resonance imaging (MRI) or for a medical treatment device, wherein the multi-channel coil comprises at least two coil rows being axially arranged along a longitudinal direction (z), wherein each of the at least two coil rows comprises a plurality of coil elements being azimuthally distributed relative to the longitudinal direction (z), comprises the steps of a) electro-magnetic decoupling of the coil rows relative to each other, and b) minimizing a reflected power (Pref—row) individually of each of the coil rows. Furthermore, a method of operating a multi-channel coil, in particular for magnetic resonance imaging (MRI) or for a medical treatment device, and a multi-channel coil, which is prepared using to the above method are described.

Abstract: According to one embodiment, a magnetic resonance imaging apparatus provided with a plurality of transmission channels includes a signal processing unit and a control unit. The signal processing unit acquires a radio frequency magnetic field emitted from each of the plurality of transmission channels through a receiver coil mounted on an object and measure a phase of the radio frequency magnetic field. The control unit determines a phase difference between the plurality of transmission channels based on the phase of the radio frequency magnetic field of each of the plurality of transmission channels measured by the signal processing unit. The control unit controls a phase of a radio frequency pulse inputted to each of the plurality of transmission channels, based on the phase difference.

Abstract: In one implementation, a memory device includes non-volatile memory, a memory controller communicatively coupled to the non-volatile memory over a first bus, and a host interface through which the memory controller communicates with a host device over a second bus. The memory device can also include a signal conditioner of the host interface adapted to condition signals to adjust a signal level of signals received over the second bus based on signal level data received from the host device, wherein the signal level data relates to a voltage level of signals generated by the host device to encode data transmitted across the second bus.

Abstract: An MRI apparatus is disclosed, the MRI apparatus comprising a computer programmed to apply a fluid suppression technique prior to an imaging pulse-gradient sequence, wherein the fluid suppression technique is configured to suppress signals from fluids having long longitudinal relaxation times, and apply a fat suppression technique after the fluid suppression technique and prior to the imaging pulse-gradient sequence, wherein the fat suppression technique is configured to suppress fat signals. The computer is further programmed to apply a flow suppression preparation sequence after the fat suppression technique and prior to the imaging pulse-gradient sequence, wherein the flow suppression preparation sequence is configured to suppress moving tissue signals. The computer is also programmed to apply the imaging pulse-gradient sequence, cause the RF transceiver system to acquire MR signals during the imaging pulse-gradient sequence, and reconstruct an image from the acquired MR signals.

Abstract: According to one embodiment, a MRI apparatus includes a data acquisition unit, a phase correction amount calculation unit and an image data generating unit. The data acquisition unit acquires MR signals in 3D k-space according to an imaging condition for HFI. The phase correction amount calculation unit calculates a first phase correction amount by applying processing including a phase correction based on k-space data for calculating the first phase correction amount and data compensation for a non-sampling region with the MR signals in the 3D k-space. The k-space data for calculating the first phase correction are MR signals less than the MR signals in the 3D k-space. The image data generating unit generates MR image data by applying processing including a phase correction using a second phase correction amount based on the first phase correction amount and the data compensation with the MR signals in the 3D k-space.

Abstract: Present embodiments are directed towards a magnetic resonance imaging method. In one embodiment, the method includes (a) performing a first magnetic resonance imaging sequence including: (i) a first preparatory composite spin locking pulse sequence having a spin lock pulse bounded by similarly oriented spin tipping pulses; and (ii) an acquisition pulse sequence to acquire first magnetic resonance data. The method further includes (b) performing a second magnetic resonance imaging sequence including: (i) a second preparatory composite spin locking pulse sequence having a spin lock pulse bounded by oppositely oriented spin tipping pulses; and (ii) an acquisition pulse sequence to acquire second magnetic resonance data. The method also includes (c) storing the first and second magnetic resonance data.

Abstract: A magnetic resonance image is produced by shifting a gap during acquisition of spin data for a specimen. The spin data is generated by a gapped excitation sequence.

Abstract: In a method and magnetic resonance system to correct phase errors in multidimensional, spatially selective radio-frequency excitation pulses in a pulse sequence used to operate the system to acquire magnetic resonance data, a multidimensional, spatially selective radio-frequency excitation pulse is radiated and multiple calibration gradient echoes are acquired. A phase correction and a time correction of the multidimensional, spatially selective radio-frequency excitation pulse is then calculated.

Abstract: In a method and magnetic resonance apparatus to continuously correct phase errors in a magnetic resonance measurement sequence in which multiple sequentially radiated, multidimensional, spatially-selective radio-frequency excitation pulses are used, multiple calibration gradient echoes are acquired in a calibration acquisition sequence and a correction value for a phase response and a correction value for a phase difference are calculated from the multiple calibration gradient echoes. Furthermore, an additional radio-frequency excitation pulse is radiated takes into account the correction values.

Abstract: A noise abatement system includes a processor configured to measure noise in an imaging system and generate a switch mode power supply (SMPS) input signal based on the measured noise and an adjustable switched mode power supply configured to receive the SMPS input signal and adjust a switching frequency of the switched mode power supply, based on the SMPS signal, to operate at a frequency that generates harmonics that are outside of an imaging bandwidth of the imaging system. A system and calibration method are also described herein.

Abstract: A system and method for automatically adjusting electrical performance of a radio frequency (RF) coil assembly of a magnetic resonance imaging (MRI) system during a medical imaging process of a subject to control changes in loading conditions of the RF coil caused by the subject during the medical imaging process.

Abstract: A method for controlling a magnetic resonance system is provided. The magnetic resonance system includes a plurality of radio-frequency transmit channels via which, in operation, parallel RF pulse trains are transmitted. The method includes specifying a common reference pulse train for the plurality of the radio-frequency transmit channels. The method also includes, determining, in an RF pulse optimization method, taking into account a prespecified target magnetization, a transmit scaling factor for each of the radio-frequency transmit channels in order to calculate the RF pulse trains for the transmit channels on the basis of the reference pulse train. The transmit scaling factors are optimized taking into account a component-induced B1 field maximum value that is dependent upon the transmit scaling factors.

Abstract: A method is offered which permits NMR measurements of integer spin nuclei to be performed at higher sensitivity than heretofore. In particular, the method enables high-resolution multidimensional correlation NMR measurements on integer spin nucleus S having integer spin S and nucleus I of other spin species. The method starts with applying an RF magnetic field having a frequency that is n times (where n is an integer equal to or greater than 2) the Larmor frequency of the integer spin nucleus S to the spin S. Magnetization transfer is effected between the nucleus I and the integer spin nucleus S.

Abstract: Apparatus, methods, and other embodiments associated with magnetic resonance (MR) trajectory correcting using GRAPPA operator gridding (GROG) are described. One example method includes identifying an on angle or regular portion of a projection in an MR trajectory and then computing base GROG weights for that portion. The example method includes identifying a shift direction and a shift amount for the projection. The shift direction is configured to shift the projection towards a desired point in k-space and the shift amount is configured to shift the projection by a desired amount in the shift direction. With a shift direction and amount available, the example method corrects for a gradient delay by manipulating the MR source signal data using the shift direction and the shift amount. In one embodiment, a gradient delay can be determined and used to calibrate an MRI apparatus.

Abstract: In a method to determine a control sequence for a magnetic resonance imaging system in order to acquire echo signal-based raw magnetic resonance data in k-space along one or more trajectories on the basis of the control sequence, the control sequence is optimized so that, to control a gradient magnetic field for at least a predetermined portion of the control sequence, a change of an attribute of the gradient magnetic field is limited. The limitation takes place so that a momentary amplitude change rate of the gradient magnetic field falls below a predetermined amplitude change rate limit value, and/or so that a momentary direction change rate of the gradient magnetic field falls below a predetermined direction change rate limit value, and/or so that a momentary gradient change rate of the gradient magnetic field that is based on a combination of the momentary amplitude change rate and the momentary direction change rate falls below a predetermined gradient change rate limit value.

Abstract: Methods for controlling magnetic resonance systems having a plurality of high frequency transmission channels through which HF pulse trains are emitted in parallel during operation are described. The methods involves specifying a joint reference pulse train for a plurality of the high frequency transmission channels, and determining a transmission scaling factor for each of the high frequency transmission channels in an HF pulse-optimization method by taking into consideration a specified target magnetization to calculate the HF pulse trains for the transmission channels on the basis of the reference pulse train. During calculation of the transmission scaling factors, a target function is created independently of a target magnetization difference in at least a first optimization mode of the HF pulse-optimization method. The target magnetization difference is considered in the HF pulse-optimization method by way of a boundary condition function instead.

Abstract: The invention relates to a method of characterizing the RF transmit chain of a magnetic resonance imaging scanner (1) using a local transmit/receive coil system (204; 210), comprising a first local NMR probe and a first local magnetic resonance coil, the first NMR probe being spatially located in immediate neighborhood to the first coil, a local receive coil system (206; 208), comprising a second local NMR probe and a second local magnetic resonance coil, the second NMR probe being spatially located in immediate neighborhood to the second coil, wherein the transmit chain comprises an external MR coil (9; 11; 12; 13), the method comprising: determining with the first magnetic resonance coil, a first MR signal phase evolution of the local RF transmit field generated by MR excitation of the first probe using the first magnetic resonance coil by measuring the RF response of the first probe upon said excitation, determining with the second magnetic resonance coil a second MR signal phase evolution of the local RF

Abstract: A method for emitting a sequence of high frequency pulses that may have different envelopes in a magnetic resonance tomography system is provided. A digital instruction signal that specifies the envelope for the high frequency pulses that are to be emitted is received. A digital control signal is transmitted to a high frequency unit for generating high frequency pulses, depending on the instruction signal. A test signal that allows notification of a current overload situation is received. The current control signal is reduced if the test signal indicates an overload situation.

Abstract: Methods are disclosed for calculating a fat fraction corrected for noise bias of one or more voxels of interest using a magnetic resonance imaging (MRI) system. A plurality of image data sets are obtained each corresponding to NMR k-space data acquired using a pulse sequence with an individual associated echo time tn. A system of linear equations is formed relating image signal values to a desired decomposed calculated data vector having a component such as a water and fat combination having zero mean noise, or having a real fat component and a real water component. A fat fraction is calculated from at least one component of the decomposed calculated data vector. In another embodiment, the system of linear equations is normalized and can directly estimate a fat fraction or a water fraction having reduced noise bias.

Abstract: A method of processing an electrical signal includes: capturing, via at least one main lead, an electrical signal; capturing, via at least one noise lead, a noise reference signal, wherein the at least one noise lead includes at least one conductive loop formed on a plane; receiving, by a processing device, the electrical signal and the noise reference signal; and processing, by the processing device, the electrical signal to cancel the noise reference signal from the electrical signal to obtain a processed electrical signal.

Abstract: A B1 magnetic field may be regulated during a magnetic resonance tomography (MRT) imaging sequence.

Abstract: A method for operating a coil, through which a varying current flows, is provided. Mechanical resonance responses of the coil are recorded and are modeled by an electrical resonant circuit model. A check is made as to whether a varying current that is to be sent through the coil evokes a resonant response in the electrical resonant circuit model. The current flow through the coil is blocked if the resonant response exceeds a predefined limit value.

Abstract: A method for position dependent change in the magnetization in an object, according to a requirement in a magnetic resonance measurement, wherein radio-frequency pulses are irradiated in conjunction with supplementary magnetic fields that vary in space and over time and are superposed on the static and homogeneous basic field of a magnetic resonance measurement apparatus along a z-direction, is characterized in that non-linear supplementary magnetic fields are used, whose spatial gradient of the z-component is not constant at least at one instant of the irradiation, and that the radio-frequency pulses to be irradiated are calculated in advance, wherein progressions over time of the field strengths of the supplementary magnetic fields in the region of the object that are calculated and/or measured position-dependently are included in this calculation.

Abstract: A method and a measuring-sequence-determining device for determining a measuring sequence for a magnetic resonance system based on at least one intra-repetition-interval time parameter are provided. During the determination of the measuring sequence in a gradient-optimization method, gradient-pulse parameters of the measuring sequence are automatically optimized to reduce at least one gradient-pulse-parameter maximum value. As a boundary condition in the gradient-optimization method, the intra-repetition-interval time parameter is kept constant at least within a specified tolerance value.

Abstract: A magnetic resonance image is produced by radial imaging using one or more preparatory pulses. The magnetic preparation pulse can include one or more adiabatic pulses.

Abstract: A controller of a magnetic resonance system determines an activation signal vector based on a target field predetermined for the controller in conjunction with field characteristics of field coils known to the controller. The activation signal vector includes a respective activation signal for each field coil. The controller determines the activation signal vector such that within a predetermined examination volume of the magnetic resonance system, any deviation of an ideal field that would result if ideal coils were subjected to the activation signals of the activation signal vector from the target field is minimized. The controller determines a compensation signal vector based on the activation signal vector in conjunction with eddy current characteristics of the field coils known to the controller. The compensation signal vector is used to minimize a deviation of an actual field from the target field within the predetermined examination volume of the magnetic resonance system.

Abstract: A gradient pulse generator generates reference current signals for a plurality of gradient coils of a gradient coil system of a magnetic resonance system and supplies each of the reference current signals to a controller assigned to one of the gradient coils. Also supplied to the respective controller is an actual current signal that is characteristic of the current flowing in the respective gradient coil. Each of the controllers generates a control signal and accordingly drives a gradient power amplifier assigned to the respective gradient coil. The gradient power amplifiers apply a current to the gradient coils assigned to the gradient power amplifiers in accordance with the generated control signals. Each of the controllers is also supplied with the reference current signal or the actual current signal of at least one other gradient coil or the time derivative of the reference current signal or the actual current signal.

Abstract: A method for correcting motion-induced phase errors in diffusion-weighted k-space data acquired with a magnetic resonance imaging (MRI) system is provided. The MRI system is directed to acquire the following data from an imaging volume: three-dimensional diffusion-weighted k-space data, three-dimensional diffusion-weighted navigator data, three-dimensional non-diffusion-weighted k-space data, and three-dimensional non-diffusion-weighted navigator data. Initial estimates of k-space shift values and a constant phase offset value are calculated using the three-dimensional diffusion-weighted navigator data and the three-dimensional non-diffusion-weighted navigator data. These initial k-space shift values and constant phase offset value are then updated by iteratively minimizing a cost function that relates the phase of the diffusion-weighted k-space data to the phase of the non-diffusion-weighted k-space data, as shifted by the initial k-space shift values and constant phase offset value.

Abstract: 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.

Abstract: According to one embodiment, a magnetic resonance imaging apparatus includes an imaging condition setting unit and an imaging unit. The imaging condition setting unit is configured to display a setting screen of a radio frequency prepulse on a display unit to set imaging conditions including application timings of radio frequency prepulses according to input information from an input device through the setting screen. The setting screen displays an application timing of a radio frequency excitation pulse and the application timings of the radio frequency prepulses on a time axis. The imaging unit is configured to perform imaging of an object according to the imaging condition.

Abstract: A device has a first control loop (28) with which a frequency RF of an RF generator is synchronized with a resonance frequency F0 of an NMR line. A phase shifter (22) is provided to rotate the radio frequency phase of the NMR receiver system in the first control loop. The phase shifter is controlled by a second control loop (27) whose input signal comes from a signal extraction stage.

Abstract: A magnetic resonance imaging apparatus according to embodiments includes an executing unit, an informing unit, a detecting unit, and a determining unit. The executing unit executes a pulse sequence to collect data of a subject at a constant cycle. The informing unit informs the subject of a timing of breathing in synchronization with the cycle at which the pulse sequence is executed. The detecting unit detects a breathing level or a respiratory cycle of the subject. The determining unit determines, when the pulse sequence is executed, whether to use the data collected by the pulse sequence for image reconstruction in accordance with the breathing level or the respiratory cycle of the subject.

Abstract: A method of synchronizing clocks between a central controlling unit and a radio frequency (RF) coil which are wirelessly connected to each other in a magnetic resonance imaging (MRI) system, which includes receiving a first clock from the central controlling unit, synchronizing a second clock of the RF coil with a received first clock, and discontinuing the receiving of the first clock from the central controlling unit when the second clock is synchronized with the first clock.

Abstract: In a method and apparatus to determine a predetermined signal amplitude of an examination subject in an MR measurement in which multiple RF pulses are radiated into the examination subject in a pulse sequence in a pulse series with a repetition time TR that is smaller than the T2 times of the examination subject, a target magnetization is established for a predetermined point in time after radiation of the respective RF pulse for essentially all RF pulses from the pulse series, a target flip angle and a target phase are determined for different regions of the examination subject for essentially all RF pulses depending on the respective target magnetization, a respective amplitude and phase response is determined for essentially all RF pulses to generate the respective target magnetization after radiation of the respective RF pulse, and the RF pulses with the respective determined amplitude and phase response are radiated into the examination subject.

Abstract: In a method for frequency calibration in a magnetic resonance system in a volume section containing an unknown number of determined substances, the predetermined volume section is excited with RF pulses and subsequent echo signals are recorded at different times and spectral information is determined for each of the echo signals, from which a peak value in the spectral information and an associated relaxation time are determined. Dependent on the relaxation time, a substance is determined for each peak value. A frequency adjustment substance dependent of the magnetic resonance system is then implemented. Multiple peak values in the spectral information of the echo signals can be determined.

Abstract: This method of adaptive signal averaging is used to enhance the signal to noise ratio of magnetic resonance and other analytical measurements which involve repeatable signals partially or completely obscured by noise in a single measurement at a rate much faster than that observed with conventional signal averaging. This technique expedites the signal averaging process because it filters each individual scan in real time with an adaptive algorithm and then averages them separately to provide an averaged filtered signal with less noise. This technique is particularly useful for any type of continuous wave magnetic resonance experiment or any other noisy measurement where signal averaging is utilized.

Abstract: A method, apparatus and computer-readable medium are provided for generating a specified transmit magnetic field profile in the presence of an object. In particular, further transmitted magnetic field profiles are obtained in the presence of the object, where the further profiles correspond to modes associated with an array of conductive elements. In addition, weighting factors associated with the modes are calculated using the specific profile and further profiles. Further, the specified profile can be generated by applying signals to ports associated with the conductive elements, where the signals are based on the weighting factors.

Abstract: A magnetic resonance method for using radio frequency pulses for spatially selective and frequency selective or multidimensionally spatially selective excitation of an ensemble of nuclear spins with an initial distribution of magnetization in a main magnetic field aligned along a z-axis, wherein a spin magnetization with a given target distribution of magnetization is generated, and for refocusing the spin magnetization, is characterized in that the radio frequency pulse is used as a sequence of sub-pulses of independent duration, courses of gradients and spatial and/or spectral resolution, comprising one or more large angle RF pulses with tip angles greater than or approximately equal to 15°, which generate a gross distribution of magnetization approximating the target distribution of magnetization or a desired modification of the distribution of magnetization with a mean deviation less than or approximately equal to 15°, wherein the actual effect of the LAPs on the distribution of spin magnetization before

Abstract: A magnetic resonance imaging “MRI” method and apparatus for lengthening the usable echo-train duration and reducing the power deposition for imaging is provided. The method explicitly considers the t1 and t2 relaxation times for the tissues of interest, and permits the desired image contrast to be incorporated into the tissue signal evolutions corresponding to the long echo train. The method provides a means to shorten image acquisition times and/or increase spatial resolution for widely-used spin-echo train magnetic resonance techniques, and enables high-field imaging within the safety guidelines established by the Food and Drug Administration for power deposition in human MRI.