Signal Polarity Restoration in IR Sequence for T1-Mapping in the DGEMRIC Technique.

Jerzy Szumowski¹, Michael Durkan, Katrina Heiles², Dawson Brown, Erwin Schwarz, Dennis Crawford

We present a reconstruction algorithm that restores image signal polarity in IR sequence and effectively doubles the dynamic range of data used for T1 curve fitting in the DGEMRIC technique. We applied this reconstruction algorithm with 3D IR gradient-echo sequence for T1 mapping, validated the technique in a phantom study and performed T1-map calculations in post osteochondral allograft transplant (OAT) patients and non-symptomatic volunteers. The proposed algorithm significantly improves reliability of T1 relaxation time fits to an inversion-recovery 3-parameter function. The algorithm can be applied to any 2D or 3D IR acquisition sequence used in conjunction with the DGEMRIC technique.