Abstract: Example apparatus and methods employ an artificial neural network (ANN) to automatically design magnetic resonance (MR) pulse sequences. The ANN is trained using transverse magnetization signal evolutions having arbitrary initial magnetizations. The trained up ANN may then produce an array of signal evolutions associated with a pulse sequence having user selectable pulse sequence parameters that vary in degrees of freedom associated with magnetic resonance fingerprinting (MRF). Efficient and accurate approaches are provided for predicting user controllable MR pulse sequence settings including, but not limited to, acquisition period and flip angle (FA). The acquisition period and FA may be different in different sequence blocks in the pulse sequence produced by the ANN. Predicting user controllable MR pulse sequence settings for both conventional MR and MRF facilitates achieving desired signal characteristics from a signal evolution produced in response to an automatically generated pulse sequence.

Abstract: In a method and apparatus for acquiring magnetic resonance (MR) data, MR signals are acquired simultaneously from S slices, of a total of N slices of a subject, with S being an SMS factor. The N slices are respectively at different positions from an isocenter of the data acquisition scanner, thereby causing said MR signals to be affected differently by Maxwell terms of magnetic fields that give said MR signals respective signal dephasings that are dependent on the distance of a respective slice from the isocenter. The SMS MR data acquisition sequence is executed with a spacing between each pair of adjacent slices being less than N/S. Maxwell correction gradient moments are calculated at an average position between the S slices, thereby generating corrected k-space data wherein the signal dephasing of the MR signals from the S slices is reduced.

Abstract: An approach is presented to recontruct image data for an object using a partial set of magnetic resonance (MR) measurements. A subset of data points in a data space representing an object are selected (e.g. through random sampling) for MR data acquisition. Partial MR data corresponding to the subset of data points is received and used for image reconstruction. The overall speed of image reconstruction can be reduced dramatically by relying on acquisition of data for the subset of data points rather than for all data points in the data space representing the object. Compressive sensing type arguments are used to fill in missing measurements, using a priori knowledge of the structure of the data. A compressed data matrix can be recovered from measurements that form a tight frame. It can be established that these measurements satisfy the restricted isometry property (RIP). The zeroth-order regularization minimization problem can then be solved, for example, using a 2D ILT approach.

Abstract: An image processing apparatus according to an embodiment includes processing circuitry. The processing circuitry is configured to obtain one or more complex product signal values each indicating a signal value of a complex product and a complex ratio signal value indicating a signal value of a complex ratio calculated in units of pixels by using first data and second data successively acquired by implementing a gradient echo method after an Inversion Recovery (IR) pulse is applied and to derive a T1 value of each of the pixels from one of the complex product signal values selected on the basis of the obtained complex ratio signal value.

Abstract: Provided is a system and method for performing a magnetic resonance fingerprinting imaging process. The process includes determining acquisition parameters including at least one of repetition time (TR) or flip angle (FA), selected to control one of a duration and a number of repetitions of for a pulse sequence that samples k-space in a Cartesian acquisition pattern by acquiring an echo train. The process also includes controlling a magnetic resonance imaging (MRI) system to perform the pulse sequence a plurality of times to acquire magnetic resonance fingerprinting (MRF) data corresponding to signals from the subject excited by the pulse sequence. The process also includes estimating quantitative tissue properties of the subject by comparing the MRF data to a database and reconstructing, from the MRF data, at least one image of the subject indicating the estimated quantitative tissue properties.

Abstract: Provided are a magnetic resonance imaging (MRI) apparatus and method for obtaining a plurality of MR images having different contrasts by using a single pulse sequence. The MRI apparatus includes a controller configured to control a pulse sequence of one cycle to be applied to a plurality of slices of an object, wherein the one cycle includes a first obtaining section during which a first inversion radio frequency (RF) pulse is applied to a first slice of the object and a second obtaining section during which a second inversion RF pulse is applied to a second slice of the object adjacent to the first slice, and to sequentially obtain a first MR signal for capturing a first MR image of the first slice, a second MR signal for capturing at least one second MR image of the second slice adjacent to the first slice, and a third MR signal for capturing at least one third MR image of the first slice, during the first obtaining section.

Abstract: A low-field magnetic resonance imaging (MRI) system. The system includes a plurality of magnetics components comprising at least one first magnetics component configured to produce a low-field main magnetic field B0 and at least one second magnetics component configured to acquire magnetic resonance data when operated, and at least one controller configured to operate one or more of the plurality of magnetics components in accordance with at least one low-field zero echo time (LF-ZTE) pulse sequence.

Abstract: The present disclosure provides a system for and a method of obtaining a magnetic resonance image by performing magnetic resonance imaging (MRI) at multiple slices simultaneously. The method comprises generating a multiband pulse sequence for spin-echo imaging, the pulse sequence comprising a multiband excitation pulse and at least one multiband refocusing pulse, wherein the multiband excitation pulse simultaneously excites multiple bands, wherein the at least one multiband refocusing pulse simultaneously refocuses the multiple bands, and wherein the phases of the bands excited by the multiband excitation pulse and the phases of the bands refocused by the at least one multiband refocusing pulse are set according to a single row of an orthogonal encoding matrix. The multiband excitation pulse and the at least one multiband refocusing pulse collectively form a multiband pulse pair.

Abstract: In one embodiment, a medical image processing apparatus which analyzes blood flow dynamics in a predetermined region of a subject, the blood flow dynamics being generated from medical images obtained by imaging the predetermined region in time sequence over a plurality of time phases. The medical image processing apparatus includes memory circuitry configured to store a program; and processing circuitry configured to correct pixel values of a second medical image according to an amount of deformation of the second medical image when the second medical image is aligned with a first medical image by executing the program read out from the memory circuitry, the first medical image and the second medical image being among the medical images in the plurality of time phases.

Abstract: A plurality of coordinates are mapped to respective first voxels. Each first voxel is assigned a value f(0), f(n) being a monotonic function defined between 0 and M inclusive. A plurality of second voxels {vi}, each of which is at a distance 1?d(vi)?M voxels from a nearest first voxel, are assigned respective second values {f(d(vi))}. Each of at least some of the second voxels is then iteratively assigned a weighted average of respective values of its immediate neighbors, any value differing from f(M) by not more than a first threshold being given a higher weight than any other value. A subset of the second voxels, each of which has a value differing from f(M) by more than a second threshold, are identified. Subsequently, a mesh representing a surface of a volume including the first voxels and the subset of the second voxels is generated.

Abstract: An image processing apparatus according to an embodiment includes conversion circuitry, magnitude image generating circuitry and phase image generating circuitry. The conversion circuitry is configured to convert time-series k-space data into first time-series x-space data, the x-space representing a spatial position. The magnitude image generating circuitry is configured to generate a magnitude image from second time-series x-space data, the second time-series x-space data being acquired by applying a first filter to the first time-series x-space data. The phase image generating circuitry is configured to generate a phase image from third time-series x-space data, the third time-series x-space data being acquired by applying, to the first time-series x-space data, a second filter that is different from the first filter.

Abstract: Technologies including NMR relaxation time estimation methods and corresponding apparatus are disclosed. Example techniques may include performing at least one single-pulse acquisition sequence, the single-pulse acquisition sequence comprising transmitting a single modulated pulse with a surface coil, wherein the phase, frequency, or amplitude of the single modulated pulse is varied during the single modulated pulse, and wherein the single modulated pulse excites a transverse magnetization component within a subsurface fluid. The resulting NMR signal may be recorded on at least one receiving device, including recording the NMR signal associated with the transverse magnetization component excited by the single modulated pulse. Processing techniques may be applied in which recorded NMR response data are used to estimate NMR properties and the relaxation times T1 and T2* as a function of position as well as one-dimensional and two-dimension distributions of T1 versus T2* as a function of subsurface position.

Abstract: In a general aspect, a magnetic resonance system includes a primary magnet system configured to generate a principal magnetic field in a sample region. The magnetic resonance system also includes a field source device. The field source device includes a substrate and first and second conductor layers on the substrate. The first conductor layer includes a constriction configured to generate a radio frequency magnetic field in the sample region. The second conductor layer is vertically centered above the first conductor layer, and includes gradient coils configured to generate first, second, and third magnetic field gradients along respective first, second and third mutually-orthogonal spatial dimensions in the sample region.

Abstract: Provided is a gradient magnetic field generation module using multiple coils to generate a gradient magnetic field. Provided is a gradient magnetic field generation module including: a gradient coil formed inside a main magnet and generating a gradient magnetic field and including a plurality of coils; and a gradient amplifier controlling at least one of a shape of the gradient magnetic field, a strength of the gradient magnetic field, and slew rate of the gradient magnetic field generated by the gradient coil, in which the plurality of coils is grouped into a plurality of coil groups and current which flows in the plurality of coils is independently controlled by the unit of a group by the gradient amplifier.

Abstract: Methods of making a white matter fibrogram representing the connectome of the brain of a subject, comprising: (a) performing a multispectral multislice magnetic resonance scan on the brain of a subject, (b) storing image data indicative of a plurality of magnetic resonance weightings of each of a plurality of slices of the brain of the subject to provide directly acquired images, (c) processing the directly acquired images to generate a plurality of quantitative maps of the brain indicative of a plurality of qMRI parameters of the subject, (d) constructing a plurality of magnetic resonance images indicative of white matter structure from the quantitative maps, and (e) rendering a white matter fibrogram of the brain of the subject from the plurality of magnetic resonance images.

Abstract: In a method and apparatus for acquiring magnetic resonance image data, improved preparation of nuclear spins is achieved by radiating at least one inversion pulse, which acts site-selectively on at least one inversion pulse range, with the at least one inversion pulse range being situated at least partially outside the area under examination, radiation of at least one excitation pulse, read-out of magnetic resonance signals from the area under examination, and reconstruction of magnetic resonance image data from the read-out magnetic resonance signals, the magnetic resonance image data depicting the area under examination.

Abstract: A system includes a storage device storing a set of instructions and a processor in communication with the storage device. When executing the instructions, the processor is configured to cause the system to obtain one or more scanning parameters. The processor is also configured to cause the system to determine a first flip angle of a first fat suppression RF pulse and a second flip angle of a second fat suppression RF pulse. The processor is further configured to cause the system to scan a subject by applying an RF pulse sequence including the first fat suppression RF pulse, the second fat suppression RF pulse, and an excitation RF pulse. The processor is also configured to cause the system to receive magnetic resonance signals based on the scanning of the subject and reconstructing an image of the subject based on the MR signals.

Abstract: The present disclosure relates to methods and systems for signal processing using coordinate descent technique for solving technical implementation problems that are expressed as unit-modulus least squares (UMLS) and unit-modulus quadratic program (UMQP) problems. Embodiments provide for iteratively minimizing an objective function of a signal vector associated with a UMLS/UMQP problem expression over a set of coordinates of the signal vector to a convergence point. The objective function is minimized with respect to a vector element corresponding to a selected coordinate index, while other vector elements that do not correspond to the selected coordinate index are fixed. Accordingly, at each iteration, minimizing the objective function involves a solution to a one-dimensional univariate quadratic minimization. Embodiments also provide various coordinate index selection rules that include a cyclic CD rule (CCD), a randomized CD rule (RCD), randomly permuted CD rule (RPCD), and a greedy CD rule (CCD).

Abstract: Methods, systems, computer programs, circuits and workstations are configured to generate at least one two-dimensional weighted CBF territory map of color-coded source artery locations using an automated vascular segmentation process to identify source locations using mutual connectivity in both image and label space.

Abstract: A method for generating a magnetic resonance image includes applying a radio frequency (RF) pulse to a specimen. The method includes modulating a spatially varying magnetic field to impart an angular velocity to a trajectory of a region of resonance relative to the specimen. The method includes acquiring data corresponding to the region of resonance and reconstructing a representation of the specimen based on the data.

Abstract: An MR apparatus creating a timeline suitable for data acquisition in several temporal phases. The MR apparatus including a method for creating a timeline TL2 having a scan time of TS1 based on a reference timeline TL0 having a scan time of TS. The method setting start points in time of scans SC1, SC3 and SC4 in the timeline TL2 to the same points in time as those in the reference timeline TL0, respectively. The method also setting the start point in time of the scan SC2 in the timeline TL2 to a sum of the scan time TS1 and a delay time TD1 with respect to the scan SC1 in the timeline TL2.

Abstract: An adjustment device (1) for an RF resonant circuit (96) of an NMR probe (90) has a plurality of movable elements (6) which are arranged in succession, such that adjacent movable elements mutually engage, so as to be movable relative to one another in a limited range. The movable elements each have at least one electrical functional part (20; 20a-20b) for adjusting the RF resonant circuit. N outwardly oriented electrical contact elements (15; 15a-15b; 23, 24) include at least two functional part terminals (21, 22), and the electrical contact elements are each connected to a functional part terminal. The adjustment device also includes a first connection assembly (11) for slidingly contacting at least a portion of the movable elements from outside, to contact the contact elements in dependence on the movement position of the movable elements, as well as a movement device (4), configured to move one of the movable elements.

Abstract: Evaluating dose performance of a radiographic imaging system with respect to image quality using a phantom, a channelized hotelling observer module as a model observer, and a printer, a plaque, or an electronic display includes scanning and producing images for a plurality of sections of the phantom using the radiographic imaging system, wherein the plurality of sections represent a range of patient sizes and doses and wherein the sections of the phantom contain objects of measurable detectability. Also included is analyzing the images to determine detectability results for one or more of the contained objects within the images of the plurality of sections of the phantom, wherein the analyzing includes using a channelized hotelling observer (CHO) module as a model observer; and displaying, via the printer, the plaque, or the electronic display, a continuous detectability performance measurement function using the determined detectability results.

Abstract: Described here are systems and methods for producing high-resolution three-dimensional (“3D”) relaxation parameter maps by calibrating high-resolution 3D magnetic resonance images. As one example, high-resolution longitudinal relaxation time (“T1”) maps can be generated based on images acquired using a T1-weighted pulse sequence, and as another example high-resolution transverse relaxation time (“T2”) maps can be generated based on images acquired using a T2-weighted pulse sequence. The high-resolution images can be calibrated, for example, using a lower resolution single slice relaxation parameter map. The methods described here utilize high-resolution 3D scans and low-resolution relaxation parameter maps that are commonly available on MRI systems. The calibration is a post-processing step used to create the high-resolution 3D relaxation parameter maps from these two types of scans.

Abstract: In a magnetic resonance slice multiplexing method and apparatus, measurements are performed repeatedly subject to the assignment of additional phases to the respective slices, the additionally assigned phases being changed with reach repetition such that at least one central k-space region is sampled completely in each of the repeated acquisitions. A calibration dataset is determined from the measurement data acquired completely in the central k-space region. The calibration dataset is used when reconstructing image data for the simultaneously excited slices from the acquired measurement data.

Abstract: In some aspects, the disclosed technology relates to magnetic field monitoring of spiral echo train imaging. In one embodiment, a method for spiral echo train imaging of an area of interest of a subject includes measuring k-space values and field dynamics corresponding to each echo of a spiral echo pulse train, using a dynamic field camera and a magnetic resonance imaging (MRI) system. The dynamic field camera is configured to measure characteristics of fields generated by the MRI system; the characteristics include at least one imperfection associated with the MRI system. The spiral echo pulse train corresponds to a spiral trajectory scan from the MRI system that obtains magnetic resonance imaging data using a pulse sequence which applies spiral gradients in-plane with through-plane phase encoding.

Abstract: In a magnetic resonance apparatus and operating method therefor, movement compensation during raw data acquisition is accomplished by operating the data acquisition scanner to acquire data from a reference navigator volume at a first point in time, using a simultaneous multi-slice technique with a first acceleration factor and a first number of first slice groups, and to acquire data from a navigator volume at a second point in time, also using a simultaneous multi-slice technique, but with a second acceleration factor and a second number of second slice groups, with the first and second acceleration factors being equal. Movement information is determined from the reference navigator volume and the navigator volume, describing movement of the patient occurring between the first and second points in time. Data acquisition parameters of the scanner are set after the second point in time, dependent on the movement information, for acquiring further magnetic resonance data.

Abstract: A magnetic resonance (MR) imaging method performed by an MR imaging system includes acquiring MR data in multiple shots and multiple acquisitions (NEX), separately reconstructing the component magnitude and phase of images corresponding to the multiple shots and multiple NEX, removing the respective phase from each of the images, and combining, after removal of the respective phase, the shot images and the NEX images to produce a combined image. The method further includes using the combined image to calculate the full k-space data for each shot and NEX and replacing unacquired k-space data points with calculated k-space data points. The operations are repeated until the combined image reaches a convergence.

Abstract: A method for performing magnetic resonance imaging with variable flip angle (VFA) readouts includes preparing longitudinal magnetization of a spin system associated with a subject to a target state, yielding a prepared longitudinal magnetization. The prepared longitudinal magnetization is converted to an image using a VFA readout sequence, wherein the VFA readout sequence comprises a plurality of radio-frequency pulses with corresponding flip-angles varying according to a modulation function.

Abstract: Techniques for improving the performance of a quantum processor are described. Some techniques employ reducing intrinsic/control errors by using quantum processor-wide problems specifically crafted to reveal errors so that corrections may be applied. Corrections may be applied to physical qubits, logical qubits, and couplers so that problems may be solved using quantum processors with greater accuracy.

Abstract: A method of parallel magnetic resonance imaging of a body, comprising:—acquiring a set of elementary magnetic resonance images of said body from respective receiving antennas having known or estimated sensibility maps and noise covariance matrices, said elementary images being under-sampled in k-space; and performing regularized reconstruction of a magnetic resonance image of said body; wherein said step of performing regularized reconstruction of a magnetic resonance image is unsupervised and carried out in a discrete frame space. A method of performing dynamical and parallel magnetic resonance imaging of a body, comprising:—acquiring a set of time series of elementary magnetic resonance images of said body from respective receiving antennas having known or estimated sensibility maps and noise covariance matrices, said elementary images being under-sampled in k-space; and performing regularized reconstruction of a time series of magnetic resonance images of said body.

Abstract: In a method for operating a magnetic resonance (MR) apparatus, at least one first distortion-corrected MR image is displayed at a display screen, with a first selection symbol superimposed thereon for selection of a scan volume from which diagnostic MR data are to be subsequently acquired. A second MR image is also displayed, that is at least partially distorted, and which represents at least a part of the region encompassed by the first distortion-corrected MR image. The second MR image is superimposed with a second selection symbol that indicates the same scan volume defined by the first selection symbol, but in the second magnetic resonance image. The second selection symbol is then used by an operator to select the actual scan volume from which the diagnostic MR data will be acquired, and a magnetic resonance apparatus is operated to acquire the MR data from that selected scan volume.

Abstract: The present disclosure provides a method and system for correcting errors caused by non-linearities in a gradient field profile of a gradient coil in a magnetic resonance imaging (MRI) system. The method includes obtaining a non-linearity tensor at each voxel within the imaging space using a computer model of the gradient coil; correcting motion sensitive encoding using the non-linearity tensor; and generating a corrected image using the corrected motion sensitive encoding.

Abstract: The present disclosure provides a method and system of magnetic resonance imaging using a constrained gradient waveform. The constrained gradient waveform is designed to have only predetermined frequencies, for example excluding one or more identified resonant frequencies associated with the MRI system. The application of such a constrained gradient waveform during imaging may aid in reducing noise, vibration and/or heating of the MRI system during imaging.

Abstract: A magnetic resonance coil and a magnetic resonance imaging system using the same are provided. The magnetic resonance coil may include an antenna and a signal processor. The antenna may be configured to receive a radio frequency (RF) signal emitted from an object, wherein the antenna does not resonate with the RF signal. The signal processor may be coupled to the antenna configured to process the RF signal to generate a processed signal.

Abstract: An ultrahigh resolution magnetic resonance imaging method and apparatus, the method comprises the following steps of: placing a test sample within an action range of a magnetic gradient source and a nano-scale superconducting quantum interference device, applying a static magnetic field on the test sample by a static magnetic source, and applying a nuclear magnetic resonance radio-frequency pulse on the test sample by a radio-frequency source to excite the test sample to cause nuclear magnetic resonance; directly coupling the nano-scale superconducting quantum interference device with the test sample to detect nuclear magnetic resonance spectrum signals generated by the test sample; establishing an image of the test sample according to the detected nuclear magnetic resonance spectrum signals and space distribution information of gradient magnetic fields generated by the magnetic gradient source.

Abstract: Apparatuses and methodologies are provided that utilize at least one polarizing magnet controlled and positioned to polarize spins in a first region of interest, at least one gradient coil controlled and positioned to generate phase-encoding gradient pulses within a second region of interest, and at least one radiofrequency coil controlled and positioned to acquire radiofrequency signals from the second region of interest, wherein the at least one gradient coil and at least one radiofrequency coil may be controlled such that application of phase-encoding gradient pulses stops before acquisition of radiofrequency signals.

Abstract: A Q value of the RF irradiation coil is easily obtained in a state in which an object is disposed in an MRI apparatus, and an SAR is predicted with high accuracy. For this, an irradiation coil 14a irradiates an object 1 with a high frequency magnetic field pulse in a state in which the object 1 is disposed in an imaging space, and a transmitted voltage and a reflected voltage of the irradiation coil 14a are detected. A Q value of the irradiation coil in a state of the object 1 being disposed is obtained on the basis of the transmitted voltage and the reflected voltage. A specific absorption rate (SAR) in a case of executing an imaging pulse sequence on the object is predicted by using the Q value.

Abstract: According to the present invention, accurate T2* and vascular images are concurrently acquired by acquiring a T2* image without a flow compensation and a T2* image with a flow compensation and subtracting the two images to reconstitute an image showing the flow phenomenon. Furthermore, an accurate T2* image can be acquired by using the readout gradient without the flow compensation and also the accurate T2* and vascular images can be concurrently acquired. The clinical judgment for blood flow rate of the blood vessel and the clinical judgment for acute stroke can be concurrently made, and so the present invention can be widely utilized in clinical practice.

Abstract: A magnetic resonance imaging apparatus includes a static magnetic field generator, a gradient magnetic field generator, a transmission coil and a processing circuitry. The static magnetic field generator generates a static magnetic field. The gradient magnetic field generator generates a gradient magnetic field. The transmission coil applies an RF pulse to an object. The processing circuitry determines high frequency pulse power absorbed by other than the object in accordance with a volume of the object and computes a specific absorption rate (SAR) with the determined high frequency pulse power.

Abstract: In a method and apparatus for optimizing the signal-to-noise ratio (SNR) of a magnetic resonance (MR) dataset acquired by means of a magnetic resonance system having at least one transmit coil, a measurement protocol for an acquisition that is to be performed in order to obtain the MR dataset of a predefined measurement volume. A deviation of an actual flip angle from the predefined flip angle in a specific area of the predefined measurement volume is determined for a preset transmitter scaling. The transmitter scaling of the RF pulse is adjusted in order to correct the actual flip angle so that the actual flip angle is approximated to the predefined flip angle in the specific area. The MR dataset is acquired with the adjusted transmitter scaling.

Abstract: An MRI method includes: performing a first data acquisition block of a pulse sequence to acquire a first MR data from a plurality of slices of a subject during a period of fully recovered longitudinal magnetization within the plurality of slices disposed at different locations in the subject; performing a second data acquisition block of the pulse sequence including a magnetization preparation module followed by a recovery period and an imaging sequence executed during the recovery period, to acquire a second MR data from the plurality of slices during the recovery period; and generating a T1 map of the subject based on the first MR data and the second MR data, of the plurality of slices.

Abstract: The present disclosure relates to a therapy system (100) comprising a radiotherapy device (102) configured to deliver and direct a radiotherapy beam along an axis to a predefined target position (117) in an imagine zone (138, 146) within an MR module (106) of the therapy system (100). The predefined target position (117) is matched with a position of an RF coil (140) of the MR module (106).

Abstract: A stored volumetric scene model of a real scene is generated from data defining digital images of a light field in a real scene containing different types of media. The digital images have been formed by a camera from opposingly directed poses and each digital image contains image data elements defined by stored data representing light field flux received by light sensing detectors in the camera. The digital images are processed by a scene reconstruction engine to form a digital volumetric scene model representing the real scene. The volumetric scene model (i) contains volumetric data elements defined by stored data representing one or more media characteristics and (ii) contains solid angle data elements defined by stored data representing the flux of the light field. Adjacent volumetric data elements form corridors, at least one of the volumetric data elements in at least one corridor represents media that is partially light transmissive.

Abstract: In the present invention, a current plane which is virtually disposed and surrounds a measurement position is assumed from magnetic field measurement values, and a current distribution (or magnetic moment distribution) which mimics a measured magnetic field is reproduced with current potentials. This is used to perform shimming calculation by a truncated singular value decomposition method with discrete shim trays that are actually used and ideal virtual continuous shim trays to carry out shimming under conditions for shimming having a uniformity that is close to ideal shimming.

Abstract: In a method and a magnetic resonance (MR) apparatus for diffusion-gradient MR imaging, vectors for the diffusion gradients are determined by generating a cuboid with edges that represent the maximum amplitudes that are achievable by the gradient system of the MR apparatus, and a spherical shell is also generated that represents limit values for effective gradient amplitudes. Areas of the spherical shell that are within the cuboid are used as end points of origin vectors that originate from the origin of the intersecting axes of the gradient system. Diffusion gradient vectors that are to be used for acquiring the diffusion-weighted MR data are then selected from these origin vectors dependent on fulfillment of a condition for producing a trace-weighted image with low artifacts.

Abstract: An apparatus, a system, and a chip are provided for improving RF system performance in MRI systems. The apparatus includes a radio-frequency (RF) coil array disposed at least partially in a coil housing, where the RF coil array may include at least one coil configured to receive magnetic resonance (MR) RF signals. The apparatus also includes a mixer disposed in the coil housing and electronically connected to the RF coil array, where the mixer converts MR RF signals from the RF coil array to intermediate-frequency (IF) signals. An electronic amplifier is disposed in the coil housing. The electronic amplifier is electronically connected to the mixer and is configured to amplify IF signals from the mixer to amplified IF signals.

Abstract: A multichannel radio frequency (RF) receive/transmit system (200) for use in an magnetic resonance (MR) imaging system (110) includes an RF coil array (202) with multiple RF coil elements (204) for emission and reception of RF signals. Each RF coil element (204) is provided with a tuning/matching circuit (208) for comparing forward power provided to at least one of the RF coil elements (204) with reflected power at the respective RF coil element (204) of the at least one of the RF coil elements (204), and for tuning the at least one of the RF coil elements (204) based on a comparison of the forward power and the reflected power at least one of the RF coil elements (204). A magnetic resonance (MR) imaging system (110) which includes the multichannel RF receive/transmit system (200) performs magnetic resonance (MR) imaging.

Abstract: In a method for generating a measurement protocol for medical imaging of an object under examination, measurement parameters of the measurement protocol are divided into a protocol structure with a base class and classes supplementing the base class. The base class includes only hardware-independent measurement parameters and the supplementary classes includes only hardware-specific measurement parameters. A method for transferring a measurement protocol, a measurement protocol generation computer, a measurement protocol conversion apparatus, and a medical imaging system make use of such a measurement protocol.

Abstract: Techniques, systems and apparatus are described for magnetic resonance imaging by modifying the shape/thickness of an excitation/inversion slab. For instance, the inversion slab can be shaped as a wedge to improve temporal signal-to-noise ratio (tSNR) of arterial spin labeling (ASL) experiments by matching the temporal bolus width with the inter-pulse spacing in different feeding arteries. The shape/thickness of the excitation/inversion slab across the X-Y plane can be modified by modulating the movement of the “on-resonance” plane in space by the combination of conventional slice-selective (SS) adiabatic fast passage (AFP) and additional in-plane gradient pulses. Using this method, a computer can generate different shapes of the excitation/inversion slab.