Abstract #0027

Fast Unwrapping using Discrete Gradient Evaluation (FUDGE): an analytical correction to the Laplacian-based phase unwrapping technique for discrete data.

Amanda Ching Lih Ng¹, Meei Pyng Ng², Sonal Josan³, Shawna Farquharson⁴, Claire Mulcahy⁴, and Roger J Ordidge¹

¹Dept of Anatomy & Neuroscience, The University of Melbourne, Parkville, Australia, ²Dept of Mathematics & Statistics, The University of Melbourne, Parkville, Australia, ³Siemens Healthcare, Melbourne, Australia, ⁴Imaging, The Florey Institute of Neuroscience and Mental Health, Melbourne, Australia

Laplacian-based phase unwrapping is commonly used to pre-process phase for methods such as Quantitative Susceptibility Mapping (QSM). However, the formulation was derived with the assumption of a continuous signal and a continuous Fourier transform. When applied to discrete MRI phase data, serious errors in phase can occur, resulting in substantial errors in QSM estimates. We present a mathematically correct Laplacian-based phase unwrapping formula, based on the assumption of the discrete nature of MRI phase data and processing. Our results reflect the mathematical predictions of the old and new formulations.

How to access this content:

For one year after publication, abstracts and videos are only open to registrants of this annual meeting. Registrants should use their existing login information. Non-registrant access can be purchased via the ISMRM E-Library.

After one year, current ISMRM & ISMRT members get free access to both the abstracts and videos. Non-members and non-registrants must purchase access via the ISMRM E-Library.

After two years, the meeting proceedings (abstracts) are opened to the public and require no login information. Videos remain behind password for access by members, registrants and E-Library customers.

Click here for more information on becoming a member.