2-D and 3-D phase unwrapping in MRI
Speaker
Prof Phil Bones (on behalf of Laura King and Rick Millane)
Institute
Department of Electrical and Computer Engineering University of Canterbury
Time & Place
Fri, 26 May 2017 14:00:00 NZST in Kirkwood KH03
Abstract
In MRI the presence of metal implants causes severe artifacts in images. The Dixon method can be used to estimate the magnetic field disturbance and improve the images. However, this requires an undersampled phase estimate to be "unwrapped". We have developed POP, phase estimation by onion peeling, an algorithm which unwraps the phase along 1-D paths for a 2-D image, starting well away from the metal implant. Phase is expanded using a smooth periodic
basis along each path. In principle, POP can be extended to 3-D imaging (expanding phase over a series of enclosing closed surfaces). Results are presented for 2-D images of phantoms and actual patients. The practicality of the method
and its employment in clinical MRI are discussed. The proposed (i.e., half-baked ideas) basis for "POP-3D" is presented.