摘要:
The present invention is directed to a method of MR imaging whereby a k-space blade extending through a center of k-space from a subject in motion is acquired. A high-pass convolution of the k-space blade with a reference k-space blade is then determined and converted to a δ function. In-plane motion of the subject during data acquisition of the k-space is then determined from the δ function.
摘要:
A nuclear magnetic resonance (NMR) technique for producing multiplexed NMR echo trains. The present invention results in the placement of discrete copies of the original spin-echo in a line along k-space. Utilizing a conventional NMR apparatus, a longitudinal magnetic field is first generated. Next a train of NMR spin-echoes is created by imprinting a repetitive pattern on the longitudinal magnetization. This pattern is composed of a sum of complex exponentials. The spins are then evolved and observed in an uninterrupted readout period. The result is an NMR pulse sequence (10) which splits the spin-echo into a series of spin-echoes thereby permitting the sampling of k-space in a single data acquisition. In the preferred embodiment, the multiplexed echo train technique of the present invention is applied to single-shot magnetic residence imaging (MRI) to permit rapid collection of data, fast screening, and two or three-dimensional imaging in clinically practical times.
摘要:
The present invention provides a system and method of MR imaging particularly applicable with fast spin echo protocols. Odd and even echoes are used to create separate blades or strips in k-space. Preferably, each blade extends through the center of k-space. The blades are incrementally rotated about the center of k-space with each echo train until a full set of k-space data is acquired. After a phase correction, each odd and even blade is combined into a single k-space data set that is used for image reconstruction.
摘要:
The present invention provides a system and method of MR imaging particularly applicable with fast spin echo protocols. Odd and even echoes are used to create separate blades or strips in k-space. Preferably, each blade extends through the center of k-space. The blades are incrementally rotated about the center of k-space with each echo train until a full set of k-space data is acquired. After a phase correction, each odd and even blade is combined into a single k-space data set that is used for image reconstruction.
摘要:
A process and system to implement such a process is configured to determine diffusion properties within a region-of-interest. A metric or index of diffusion is determined from individual diffusion values corresponding to diffusion along, multiple diffusion directions relative to average diffusion at a related voxel or pair of voxels. The invention may be implemented to determine shared diffusion anisotropy between two voxels. Based on a value of a diffusion index or metric, the present invention provides an efficient and tensor-free technique of determining if diffusion in neighboring voxels is anisotropic and if the diffusion is oriented in the same direction within each voxel. The present invention may be used to rapidly determine fractional anisotropy in a single voxel or used to filter diffusion weighted imaging data. The present invention may also be used to color-code diffusion data such that diffusion and tract orientation are readily identifiable in a reconstructed image.