A Simple Approach for Quantifying T1 and Macromolecular Proton Fraction from Rapid Inversion Recovery with 3D stack-of-spiral FLASH readout

Motivation: Simultaneous Quantification of T1 and macromolecular proton fraction (fm) is desired but current methods are time consuming. Goal(s): To develop an approach for quantitative mapping of both apparent T1 and fM from inversion recovery (IR) curves. Approach: IR curves with efficient 3D stack-of-spiral FLASH readout were fitted with a monoexponential function, extracting both the apparent T1 and the inversion degree with the latter to determine fm. This method was evaluated through theory, simulation, phantom, and brain experiments. Results: This study demonstrated a simple and rapid approach for 3D mapping of both apparent T1 and fm. Impact: A simple and rapid approach for quantitative mapping of both apparent T1 and macromolecular proton fraction (fm) will help understanding the T1 contrast mechanism and facilitate developing pathological biomarkers for various clinical applications.