A new phase unwrapping algorithm

Abstracts-part XI

“…At the moment, there is not enough experience to determine the robustness of the full method, though, for example, amongst other problems there is some reservation on the computation of the chemical concentrations using the triangulation method (6). Introduction: Magnetic Resonance (MR) imaging provides inherent three dimensional (3-D) information.…”

“…They a l s o a r e c a p a b l e of compressing s h a r p s i g n a l s very e f f i c i e n t l y [ 6 ] .…”

Phase‐unwrapping algorithm for translation extraction from spherical navigator echoes

“…The first step in the SNAV phase-unwrapping algorithm is to identify and remove sharp phase discontinuities, a step common to other phase unwrapping algorithms (7,8). However, in the case of noisy SNAV data, subtraction of neighboring sample points is not possible and the phase of the current sample point l must be subtracted from the average phase of w neighboring points:…”

“…The most commonly used one-dimensional phaseunwrapping algorithms calculate the unwrapped phase by summing the derivative of the phase (7,8). However, these algorithms result in relative measures of phase, rather than measuring the absolute phase value, and are highly susceptible to noise in the measurement.…”

“…However, these algorithms result in relative measures of phase, rather than measuring the absolute phase value, and are highly susceptible to noise in the measurement. Even error in a single point can result in large cumulative errors (7), rendering common phase-unwrapping algorithms unusable with SNAV data. While phase wrapping occurs in one-dimensional navigator echoes as well, it is usually not a problem because data analysis occurs following transformation into the image domain, or algorithms involving the addition of multiples of 2p are used in high-SNR cases (1,9,10).…”