摘要:
A method for a medical examination is described. The method includes polar phase encoding to generate a plurality of signals forming datasets representative of an object, where the datasets form a grid in polar coordinates in a k-space.
摘要:
A method for a medical examination is described. The method includes polar phase encoding to generate a plurality of signals forming datasets representative of an object, where the datasets form a grid in polar coordinates in a k-space.
摘要:
A device and software system with input and output capability for manipulating real and virtual objects in 3-dimensional space. The device consists of a six degree-of-freedom mechanical armature that has sensors to determine the location and orientation of a stylus and planar surface. In the input mode, manipulation of the physical armature will result in a corresponding two-dimensional, virtual image of the stylus and surface on a computer screen. The armature also has motors to automatically change the armature location and orientation in order to generate a physical representation in the real world of the location and orientation of a virtual object. The armature is built so that it maintains balance at any location and orientation to statically maintain the armature location and orientation without drifting to a null rest position.
摘要:
A RF Excitation pulse for MRI applications has built-in saturation sidebands, thereby reducing the time for an excitation sequence. The pulse is created using the Shinnar-Le Roux (SLR) transform and designing beta-polynomials for a desired image slice excitation and for saturation of RF excitation such as by de-phasing in regions adjacent to the desired image slice. The beta-polynomials are combined and an inverse SLR transform creates the RF pulse from the combined beta-polynomial.
摘要:
A system and method for adaptive averaging of velocity spectra using variable density trajectories, comprising: acquiring at least one series of velocity spectra using interleaved variable density trajectories and sampling low kv data more often or more densely than high kv data, the series of velocity spectra further comprising at least one spectrum; identifying a series of velocity spectra that comprises at least one velocity spectrum as a template, aligning at least one of the acquired series of velocity spectra with the template using low kv data; and averaging the aligned spectra, the averaging further comprising averaging the low kv data of the aligned spectra, and combining the averaged low kv data with the high kv data of the aligned spectra, wherein the combination produces enhanced spectra.
摘要:
A method for a medical examination is provided. The method includes acquiring at least two datasets that include data acquired at a plurality of points that lie along at least two lines through a center of k-space, reconstructing the at least two datasets to generate an image, and outputting the image.
摘要:
A method for reconstructing non-uniformly sampled data to create an image includes: receiving a new partial data set, the new partial data set including a vector of non-uniformly sampled data at k-space positions; subtracting an old partial data set at the same k-space positions from the new partial data set to create a difference vector; gridding the difference vector to create a difference matrix; adding the difference matrix to a frame of previously gridded data to create a new frame; and transforming the new frame to create the image. In one embodiment, gridding includes constructing a gridding table for a data point in a complete data set, and convolving a data point in the difference vector with the gridding table. In another embodiment at least one of a grid size and a first parameter of the window function is optimized using input parameters for at least one of aliasing energy and computation time.