Fast T1 mapping determined using incomplete inversion recovery look-locker 3D balanced SSFP acquisition and a simple two-parameter model fit.

ABSTRACT

PURPOSE: To evaluate a fast T1 mapping technique using incomplete inversion recovery 3D balanced steady-state free precession acquisition along with a two-parameter model fit. MATERIALS AND METHODS: Using Bloch simulations, we explored the two-parameter model fit for data acquired using such an acquisition scheme. The parameter space over which the fit holds good was determined through simulations. A linear correction was derived for the R1* (1/T1*) values so determined. Two phantoms and six volunteers were scanned using the described technique. Comparison scans using full recovery as well as gold standard inversion recovery spin echo were also performed. RESULTS: The two-parameter fit works exceedingly well over a large parameter space. T1 values in the phantoms showed an error of 4.9% and 39% before correction and 0.9% and 1.6% after correction. For the six volunteers, error in T1 value was 5.3% for white matter (WM) and 2.4% for gray matter (GM) after correction, while it was 11.2% and 18.2% before correction. CONCLUSION: The work presented here allows for T1 map determination with higher resolution and shorter acquisition time than previously possible. The technique is especially well suited for GM/WM T1 mapping.