Patent classifications
G01R33/5618
IMAGE PROCESSING APPARATUS
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.
Method and magnetic resonance system to generate multiple magnetic resonance images
In a method and magnetic resonance system to determine multiple magnetic resonance images for respective different echo points in time, k-space is scanned on a segment-by-segment basis with at least two rectangular k-space segments, these being scanned line by line with respective k-space lines oriented parallel to one another. A short side of the rectangular k-space segments is oriented parallel to the k-space lines. First and second gradient echoes are respectively produced by a radio-frequency pulse radiated for each k-space line.
Systems and methods for low-field fast spin echo imaging
A magnetic resonance imaging (MRI) system and method for acquiring magnetic resonance (MR) images using a pulse sequence implementing driven equilibrium and quadratic phase cycling techniques is provided. The method includes, during a pulse repetition period of a pulse sequence and using a quadratic phase cycling scheme, applying a first RF pulse to deflect a net magnetization vector associated with the subject from a longitudinal plane into a transverse plane; after applying the first RF pulse, applying a first sequence of RF pulses each of which flips the net magnetization vector by approximately 180 degrees within the transverse plane; and after applying the first sequence of RF pulses, applying a second RF pulse to deflect the net magnetization vector from the transverse plane to the longitudinal plane.
Three-dimensional diffusion weighted magnetic resonance imaging
Techniques are provided for performing three-dimensional diffusion weighted magnetic resonance imaging. A diffusion gradient is applied by controlling a gradient coil arrangement of an MRI system and, during an acquisition period after the application of the diffusion gradient, a readout gradient is applied by controlling the gradient coil arrangement and MR data is acquired. For applying the readout gradient, the gradient coil arrangement is controlled such that the MR data is acquired at least along a trajectory segment of a three-dimensional k-space trajectory, wherein a k-space center is sampled by the trajectory segment multiple times during the acquisition period.
System and method to reduce specific absorption rate in magnetic resonance imaging
A method for imaging a subject using a magnetic resonance imaging (MRI) system includes determining a tailored radio frequency (RF) pulse sequence having a plurality of refocusing pulses. In the method, a target peak RF pulse value is determined and a transfer function to convert a first refocusing pulse of the plurality of refocusing pulses to a modified refocusing pulse with the target peak RF pulse value is also determined. A modified RF pulse sequence is generated based on the transfer function and the plurality of refocusing pulses. Finally, magnetic resonance (MR) signals from the subject are acquired based on the modified RF pulse sequence and the medical image of the subject is generated based on the acquired MR signals.
Highly accelerated sub-millimeter resolution 3D GRASE with controlled T2 blurring in T2-weighted functional MRI at 7 tesla
Accelerated GRASE with controlled T2 blurring improves a point spread function (PSF) and temporal signal-to-noise ratio (tSNR) with many slices. The approach seeks to minimize a trade-off between SNR and blurring for functional sensitivity, and uses a new GRASE-optimized random encoding, which takes into accounts for the complex signal decays of T2 and T2* weightings, by achieving incoherent aliasing for constrained reconstruction. Numerical and experimental studies validate the effectiveness of the new method over regular and VFA GRASE (R- and V-GRASE).