Feasiblity of Driven Equilibrium Single Pulse Observationof T1 (DESPOT1) at Ultra-Low Field

Motivation: Quantitative magnetic resonance imaging can provide novel insights into the brain’s tissue microstructure, however, such methods have limited availability at ultra-low field. Goal(s): To develop DESPOT1 approach at ultra-low field. Approach: We acquired spoiled gradient recalled echo images across multiple flip angles at low field (64 mT) and fit the signal to estimate T1 using the DESPOT1 framework. Results: While challenged by limited SNR at low field, our results demonstrate the feasibility to measure T1 at low field from multiple flip angle images. Through additional optimization, such methods may allow low field systems to provide sensitive measures of brain tissue microstructure. Impact: Our results demonstrate the ability to perform T1 relaxation time mapping via DESPOT1 at ultra-low field for the first time. Improvements in the described approach could enable sensitive measurements of brain microstructure at ultra-low field.