Correction of gradient distortion for low frequency current density imaging.
Published: 2006
Language: eng
Number of pages: 74
ISBN-13: 9780494211502
Description: The nonlinearity of gradient fields in magnetic resonance imaging (MRI) creates an image distortion artifact known as gradient distortion. Gradient distortion distorts low frequency current density imaging (LFCDI) through mis-registration and coordinate distortion. Mis-registration is caused by the asymmetric spatial distortion of phase images in three LFCDI orientations and coordinate distortion is caused by the spatial distortion of the Cartesian coordinate system. As a consequence, the current density vectors generated by LFCDI are distorted both in magnitude and in direction. A calibration phantom was employed to measure gradient distortion. For the first time, based on the measurements from the calibration phantom image, a distortion correction algorithm was developed to fully correct the effects of gradient distortion on LFCDI. In addition, a set of validation experiments were performed and successfully confirmed the validity of the correction algorithm.
Notes: Source: Masters Abstracts International, Volume: 45-03, page: 1619.

Advisor: Michael Joy.

Thesis (M.A.Sc.)--University of Toronto, 2006.

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