Fast High-Resolution T1 Mapping using Inversion-Recovery Look-Locker Echo-Planar Imaging at Steady State: Optimization for Accuracy and Reliability

摘要

A fast T1 measurement sequence using inversion recovery Look-Locker echo-planar imaging at steady state (IR LL-EPI SS) is presented. Delay time for a full magnetization recovery is not required in the sequence, saving acquisition time significantly for high-resolution T1 mapping. Imaging parameters of the IR LL-EPI SS sequence were optimized to minimize the bias from the excitation pulses imperfection and to maximize the accuracy and reliability of T1 measurements, which are critical for its applications. Compared with the conventional inversion recovery Look-Locker echo-planar imaging (IR LL-EPI) sequence, IR LL-EPI SS method preserves similar accuracy and reliability, while saving 20% in acquisition time. Optimized IR LL-EPI SS provided quantitative T1 mapping with 1×1×4 mm³ resolution and whole brain coverage (28 slices) in approximately 4 minutes.