Christine Hawryszko

A general algorithm for oblique image reconstruction

It is shown how to generate oblique slices from a set of parallel slices. An algorithm that can produce planes or contours through the volume without any loss of the volume resolution of the original data set is presented. The algorithm uses the Fourier-shift theorem and is efficient for calculating large numbers of slices. Although the algorithm is general, it is particularly well suited for three-dimensional magnetic resonance images, as demonstrated with examples.<<ETX>>

Applications of voxel shifting in magnetic resonance imaging.

Due to the nature of three-dimensional Fourier transform (3-DFT) data acquisition in magnetic resonance imaging (MRI), the spatial relation between a resolved volume element (a voxel) and the object can be manipulated easily. Those manipulations have practical consequences in terms of registering slice positions with respect to features of interest in producing oblique reformatted images where volume resolution is preserved, and in generating reformatted images that project the viewing plane onto a surface through the object that has an arbitrary shape.

Ghost imaging in MRI

Needle biopsies and other interventions done under MR Fluoroscopy sometimes do not show the target well, either because the rapid sequence does not have adequate contrast or because a contrast agent may have washed out of the target. In these cases, an image that shows the target can be saved and scaled to match the spatial parameters of the fluoroscopic sequence, and used as a virtual or ghost field upon which the fluoroscopic images are superimposed, thus providing a view of the target, useful for needle pre-localization and for monitoring its progress as it is inserted.