Model-free phasor image analysis of quantitative myocardial T₁ mapping

Area of Science:

• Medical Imaging
• Biophysics
• Cardiovascular Research

Background:

• Quantitative MRI (qMRI) is crucial for myocardial tissue characterization.
• Traditional qMRI analysis relies on mono-exponential fitting, which can be biased by complex signal decays.
• Phasor analysis, a model-free technique, is emerging as a powerful tool for analyzing complex decay data.

Purpose of the Study:

• To adapt and validate model-free phasor image analysis for myocardial qMRI mapping.
• To assess the performance of the full-harmonics phasor method in identifying specific qMRI challenges.

Main Methods:

• Application of model-free phasor analysis to qMRI data processing.
• Utilized a recently developed full-harmonics phasor method.
• Tested on simulated data, a healthy subject, and two patient datasets.

Main Results:

• Phasor analysis successfully mapped lifetime information from all voxels without fitting.
• The method described multi-exponential qMRI decays without model assumption biases.
• Identified motion artifacts, partial-volume effects at the myocardium-blood interface, and delineated scar tissue in patients.

Conclusions:

• Phasor analysis offers a robust, model-free alternative for myocardial qMRI.
• It effectively identifies artifacts and pathological tissue alterations.
• This technique holds promise for improved cardiac qMRI analysis.