phase unwrapping
A post-processing technique to remove 2π discontinuities in phase images, recovering true phase values across the image.
Full Definition
Phase unwrapping is a computational process applied to phase-contrast MRI data to eliminate artificial phase jumps that occur when phase values exceed the measurable range of -π to +π radians. These discontinuities create apparent phase wraps that must be corrected to accurately represent the underlying magnetic field variations or motion-encoded information. Various algorithms including path-following, minimum norm, and statistical approaches are used to reconstruct smooth, continuous phase maps essential for applications such as quantitative susceptibility mapping, flow measurement, and magnetic field mapping.
Usage
Usage note: Specify the algorithm used; critical for quantitative phase applications.
In Context
- "Phase unwrapping was performed using a Laplacian-based algorithm to correct for field inhomogeneities." — QSM processing pipeline
- "Inadequate phase unwrapping resulted in residual wrapping artifacts affecting velocity measurements." — Quality control assessment