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Full-Harmonics Phasor Analysis: Unravelling Multiexponential Trends in Magnetic Resonance Imaging Data
Wouter M J Franssen1, Frank J Vergeldt1, Arjen N Bader1,2
1Laboratory of Biophysics, Wageningen University & Research, Wageningen 6708 WE, The Netherlands.
The Journal of Physical Chemistry Letters
|October 14, 2020
Summary
Full-harmonics phasor analysis enhances Magnetic Resonance Imaging (MRI) by revealing multiple physical environments. This advanced method, applied to quantitative MRI (qMRI), surpasses traditional single-harmonic approaches for complex biological systems.
Area of Science:
- Magnetic Resonance Imaging (MRI)
- Quantitative MRI (qMRI)
- Biophysical Imaging Techniques
Background:
- Phasor analysis is a non-fitting method for multiexponential decay analysis in imaging.
- Established phasor analysis in Fluorescence Lifetime Imaging Microscopy (FLIM) and Magnetic Resonance Imaging (MRI) typically uses only the first Fourier harmonic.
- This limitation restricts the ability to resolve complex physical environments and partial-volume effects in MRI data.
Purpose of the Study:
- To demonstrate the potential of full-harmonics (FH) phasor analysis in Magnetic Resonance Imaging (MRI).
- To compare the performance of FH phasor analysis against the traditional single-harmonic approach in MRI.
- To explore the application of FH phasor analysis for complex biological systems and big-data analysis in quantitative MRI (qMRI).
Main Methods:
- Simulations were performed to evaluate the FH phasor analysis.
- Quantitative MRI (qMRI) T2 measurements were conducted on phantoms containing bulk liquids and liquid-filled porous particles.
- FH phasor analysis was applied to human brain MRI data.
Main Results:
- Full-harmonics (FH) phasor analysis outperforms single-harmonic phasor analysis in MRI.
- FH analysis effectively unravels multiple physical environments and partial-volume effects that are otherwise undiscernible.
- The advantage of FH analysis in MRI is significant, unlike in FLIM where shot noise correlation limits its benefit.
Conclusions:
- Full-harmonics (FH) phasor analysis is a powerful tool for quantitative MRI (qMRI).
- FH analysis offers superior resolution for complex biological systems and multiphase materials compared to traditional methods.
- This method holds promise for big-data analysis in qMRI where multiparameter fitting is infeasible.
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