A magnetic resonance imaging apparatus includes sequence control circuitry and processing circuitry. In CEST imaging the sequence control circuitry performs a first sequence and a second sequence under different saturation pulse conditions. The first sequence is for acquiring first magnetic resonance signals corresponding to a first frequency region of a k-space and second magnetic resonance signals corresponding to a second frequency region of the k-space. The second sequence is for acquiring third magnetic resonance signals corresponding to at least the first frequency region. The processing circuitry assigns the third magnetic resonance signals and the second magnetic resonance signals to a single k-space generated for the second sequence. Frequency including the first frequency region is lower than frequency including the second frequency region.

An MRI apparatus according to an embodiment includes sequence controlling circuitry, in a first transition period, repeating application of a first MT pulse and acquisition of a first MR signal to a first frequency region being a part of a k-space; in the first steady state, repeating application of the first MT pulse and acquisition of a second MR signal to a second frequency region of the k-space, frequency in second frequency region being lower than frequency in the first frequency region; and in a second transition period, repeating application of a second MT pulse and acquisition of a third MR signal to a third frequency region being another part of the k-space, frequency in the third frequency region being higher than the frequency in the second frequency region, and processing circuitry generating one MR image on basis of the first, second, and third MR signal.

According to one embodiment, a magnetic resonance imaging apparatus includes sequence control circuitry and processing circuitry. The sequence control circuitry performs under-sampled data acquisition whose sample points are located at an equal interval in k-space and acquires k-space frames. The processing circuitry generates a plurality of k-space frames related to a plurality of time resolutions based on the k-space frames. In each of the plurality of k-space frames, the sample points are located at an equal interval, and the interval differs for each of the plurality of k-space frames. The processing circuitry generates a time-series image based on the plurality of k-space frames.

The present disclosure provides a system and method for magnetic resonance imaging. The method may include obtaining first k-space data collected from a subject in a non-Cartesian sampling manner. The method may also include generating second k-space data by regridding the first k-space data. The method may further include generating third k-space data by calibrating the second k-space data, wherein a calibrated field of view (FOV) corresponding to the third k-space data is constituted by a central portion of an intermediate FOV corresponding to the second k-space data. The method may still further include reconstructing, using at least one of a compressed sensing algorithm or a parallel imaging algorithm, a magnetic resonance (MR) image of the subject based at least in part on the third k-space data.

A plurality of reception coils are used to acquire magnetic resonance signals using parallel imaging and a k-space acquisition scheme, in which alternatingly the central region and one of the peripheral k-space portions are imaged in acquisition steps of a pair, such that after a partition number of such pairs, the whole k-space to be acquired has been imaged and a sliding reconstruction window can be applied to reconstruct an additional magnetic resonance image after each acquisition of such a pair. A time series of magnetic resonance images forming the magnetic resonance data set is then reconstructed from the magnetic resonance signals and sensitivity information regarding the plurality of reception coils by using the sliding reconstruction window and a reconstruction technique for undersampled magnetic resonance data. The k-space trajectories for each acquisition step are chosen to allow controlled aliasing in all three spatial dimensions including the readout direction.

A magnetic resonance scanner (10) includes a main magnet (12), gradient coils (14) and a gradient coil controller (28), one or more RF coils (16,50), an RF transmitter (30), an RF receiver (34), and one or more processors (38). The main magnet (12) generates a B.sub.0 field. The gradient coils (14) and a gradient coil controller (28) generate gradients across the Bo field. The one or more RF coils (16,50) transmit B.sub.1 pulses and receive magnetic resonance signals. The RF transmitter (30) transmits B.sub.1 pulses to the RF coils to excite and manipulate resonance. The RF receiver (34) demodulates received resonance signals into data lines. The one or more processors (38) are connected to the gradient coil controller (28), the RF transmitter (30), and the RF receiver (34) and are programmed to control (70) the RF transmitter and the gradient coil controller to implement an interleaved multi-slice 2D imaging sequence which in each of a plurality of TRs generates a first and second navigation data lines and at least one image data line for each of a plurality of slices. The one or more processors are further programmed to reconstruct (74) the first navigation data lines from the plurality of slices into a first navigation projection image, reconstruct (74) the second navigation data lines from the plurality of slices into a second navigation image; and compare (76) successive navigation projection images to detect and adjust (78) for 3D motion.

In a method and a magnetic resonance (MR) system for functional MR imaging of a predetermined volume segment of THE brain of a living examination subject, an RF excitation pulse is radiated into the subject and at least one magnetic field gradient is activated, and MR data of the predetermined volume segment is acquired beginning at a predetermined echo time after the RF excitation pulse. The echo time is in a time period of 10 μs to 1000 μs.

The invention relates to a method for generating MR images (10, 20) of an object in its environment within a region of interest, said object executing motion comprising a plurality of moving phases within a period of time. According to several aspects of the invention, the method comprises the steps of: —providing a first dataset pertaining to one of the moving phases of the object (Si); —generating a first image (10) of a region of interest from the first dataset (S2); —identifying a dynamic region (12) and a static region (14) inside the first image (10), wherein the regions (12, 14) are predominantly dynamic or static respectively within the periodeperiod of time (S3); —editing the first image (10) by masking out the dynamic region (14) (S4); —performing an inverse Fourier transformation of the edited first image (16) showing the remaining static region (14) (S5); —providing a second dataset pertaining to one of the moving phases of the object (S6); —subtraction of the inverse Fourier transformation of the edited first image (16) with the remaining static region (14) from the second dataset (S7); —performing a Fourier transformation on the subtracted second dataset (18) (S8); and —generating a second image (20) of a reduced region of interest with respect to the region of interest of the first image (10), which reduced region of interest includes the dynamic region (12) (S9). The invention further relates to a corresponding MRI system for generating MR images of an object in its environment within a region of interest.

A method for performing 3D body imaging includes performing a 3D MRI acquisition of a patient to acquire k-space data and dividing the k-space data into k-space data bins. Each bin includes a portion of the k-space data corresponding to a distinct breathing phase. 3D image sets are reconstructed from the bins, with each 3D image set corresponding to a distinct k-space data bin. For each bin other than a selected reference bin, forward and inverse transforms are calculated between the 3D image set corresponding to the bin and the 3D image set corresponding to the reference bin. Then, a motion corrected and averaged image is generated for each bin by (a) aligning the 3D image set from each other bin to the 3D image set corresponding to the bin using the transforms, and (b) averaging the aligned 3D image sets to yield the motion corrected and averaged image.

A method for producing an image of a subject using a magnetic resonance imaging (MRI) system includes acquiring a series of echo signals by sampling k-space along radial lines that each pass through the center of k-space. Each projection of the radial lines is divided into multiple echoes and successive projections are spaced by a predetermined angular distance. The series of echo signals are reconstructed into a plurality of images, wherein each image corresponds to a distinct echo signal.