摘要:
The present invention provides a system and method for parallel imaging that performs auto-calibrating reconstructions with a 2D (for 2D imaging) or 3D kernel (for 3D imaging) that exploits the computational efficiencies available when operating in certain data “domains” or “spaces”. The reconstruction process of multi-coil data is separated into a “training phase” and an “application phase” in which reconstruction weights are applied to acquired data to synthesize (replace) missing data. The choice of data space, i.e., k-space, hybrid space, or image space, in which each step occurs is independently optimized to reduce total reconstruction time for a given imaging application. As such, the invention retains the image quality benefits of using a 2D k-space kernel without the computational burden of applying a 2D k-space convolution kernel.
摘要:
The present invention provides a system and method for parallel imaging that performs auto-calibrating reconstructions with a 2D (for 2D imaging) or 3D kernel (for 3D imaging) that exploits the computational efficiencies available when operating in certain data “domains” or “spaces”. The reconstruction process of multi-coil data is separated into a “training phase” and an “application phase” in which reconstruction weights are applied to acquired data to synthesize (replace) missing data. The choice of data space, i.e., k-space, hybrid space, or image space, in which each step occurs is independently optimized to reduce total reconstruction time for a given imaging application. As such, the invention retains the image quality benefits of using a 2D k-space kernel without the computational burden of applying a 2D k-space convolution kernel.
摘要:
The present invention provides a system and method for parallel imaging that performs auto-calibrating reconstructions with a 2D (for 2D imaging) or 3D kernel (for 3D imaging) that exploits the computational efficiencies available when operating in certain data “domains” or “spaces”. The reconstruction process of multi-coil data is separated into a “training phase” and an “application phase” in which reconstruction weights are applied to acquired data to synthesize (replace) missing data. The choice of data space, i.e., k-space, hybrid space, or image space, in which each step occurs is independently optimized to reduce total reconstruction time for a given imaging application. As such, the invention retains the image quality benefits of using a 2D k-space kernel without the computational burden of applying a 2D k-space convolution kernel.
摘要:
The present invention provides a system and method for parallel imaging that performs auto-calibrating reconstructions with a 2D (for 2D imaging) or 3D kernel (for 3D imaging) that exploits the computational efficiencies available when operating in certain data “domains” or “spaces”. The reconstruction process of multi-coil data is separated into a “training phase” and an “application phase” in which reconstruction weights are applied to acquired data to synthesize (replace) missing data. The choice of data space, i.e., k-space, hybrid space, or image space, in which each step occurs is independently optimized to reduce total reconstruction time for a given imaging application. As such, the invention retains the image quality benefits of using a 2D k-space kernel without the computational burden of applying a 2D k-space convolution kernel.
摘要:
The present invention provides a system and method for parallel imaging that performs auto-calibrating reconstructions with a 2D (for 2D imaging) or 3D kernel (for 3D imaging) that exploits the computational efficiencies available when operating in certain data “domains” or “spaces”. The reconstruction process of multi-coil data is separated into a “training phase” and an “application phase” in which reconstruction weights are applied to acquired data to synthesize (replace) missing data. The choice of data space, i.e., k-space, hybrid space, or image space, in which each step occurs is independently optimized to reduce total reconstruction time for a given imaging application. As such, the invention retains the image quality benefits of using a 2D k-space kernel without the computational burden of applying a 2D k-space convolution kernel.
摘要:
Disclosed is a new propeller EPI pulse sequence with reduced sensitivity to field inhomogeneities is proposed. Image artifacts such as blurring due to Nyquist ghosting and susceptibility gradients are investigated and compared with those obtained in previous propeller EPI studies. The proposed propeller EPI sequence uses a readout that is played out along the short axis of the propeller blade, orthogonal to the readout used in previous propeller methods. In contrast to long-axis readout propeller EPI, this causes the echo spacing between two consecutive phase-encoding (PE) lines to decrease, which in turn increases the k-space velocity in this direction and hence the pseudo-bandwidth.
摘要:
The tracking and compensation of patient motion during a magnetic resonance imaging (MRI) acquisition is an unsolved problem. A self-encoded marker where each feature on the pattern is augmented with a 2-D barcode is provided. Hence, the marker can be tracked even if it is not completely visible in the camera image. Furthermore, it offers considerable advantages over a simple checkerboard marker in terms of processing speed, since it makes the correspondence search of feature points and marker-model coordinates, which are required for the pose estimation, redundant. Significantly improved accuracy relative to a planar checkerboard pattern is obtained for both phantom experiments and in-vivo experiments with substantial patient motion. In an alternative aspect, a marker having non-coplanar features can be employed to provide improved motion tracking. Such a marker provides depth cues that can be exploited to improve motion tracking. The aspects of non-coplanar patterns and self-encoded patterns can be practiced independently or in combination.
摘要:
In tensor MRI, a set of k-space MRI data points is acquired that includes one or more k-space subsets of MRI data points. An object orientation (or spatial transformation) corresponding to each of the k-space subsets is determined. Because the object orientation (or spatial transformation) can differ from subset to subset, the overall set of k-space data can be inconsistent with respect to object orientation (or spatial transformation). This possible inconsistency can be addressed by providing a k-space tensor model that includes object orientation and/or spatial transformation information corresponding to each of the subsets. A tensor MRI image can be reconstructed from the set of k-space MRI data points by using the k-space tensor model to account for object orientation and/or spatial transformation.
摘要:
Measurements of functional, hemographic, and blood flow parameters use a multiple echo or spin echo gradient pulse sequence whereby an early echo is acquired near the beginning of the pulse sequence which avoids saturation effects and a later echo near the end of the pulse sequence which can provide information with more sensitivity to a contrast agent for a susceptibility weighted image.
摘要:
Phase error in MR imaging is corrected in real time by providing adaptive RF pulses and corresponding adaptive magnetic field gradients to mitigate the effect of phase error in the imaging subject. A real time phase error map is obtained, and then adaptive RF pulses and corresponding field gradients are applied that remove the problematic effects of the phase error. Depending on details of the MR imaging mode being employed, there are several ways this removal can be done. Phase error can be cancelled by providing RF pulses that make the phase in the imaging subject uniform. Another approach is to make the adaptive RF pulses insensitive to the phase errors that are present.