Temporal phase correction of multiple echo T2 magnetic resonance images

Area of Science:

• Biomedical Engineering
• Medical Imaging Physics
• Neuroimaging

Background:

• Magnetic resonance imaging (MRI) analysis typically uses magnitude data, with multiple echo T2 acquisitions providing temporal sampling of noise during signal decay.
• Rician noise in magnitude T2 decay data complicates analysis, especially with decreasing signal-to-noise ratios at longer echo times.
• Existing spatial-based phase correction methods for MRI do not leverage temporal information from multi-echo T2 data.

Purpose of the Study:

• To introduce a novel temporal phase correction (TPC) algorithm for multi-echo T2 MRI data.
• To utilize temporal noise characteristics within multi-echo T2 acquisitions to improve data quality.
• To assess the impact of TPC on T2 distribution estimation and water environment characterization.

Main Methods:

• Development of a temporal phase correction (TPC) algorithm leveraging temporal noise in multi-echo T2 MRI.
• Application of TPC to real-valued, multi-echo T2 data acquired from human subjects at 1.5 T.
• Comparison of T2 distribution estimates before and after TPC application.

Main Results:

• TPC effectively separates signal decay information into the Real data portion and noise into the Imaginary portion.
• Application of TPC resulted in significant changes to T2 distribution estimates.
• TPC enabled potential resolution of separate extracellular and intracellular water environments.
• The commonly observed cerebrospinal fluid peak in T2 distributions disappeared after TPC, suggesting it may be an artifact.

Conclusions:

• The developed TPC algorithm offers a significant advancement in analyzing multi-echo T2 MRI data.
• TPC improves the accuracy of T2 distribution estimation by addressing noise characteristics.
• This method holds promise for more precise characterization of water environments, including distinguishing between intracellular and extracellular spaces.