Flip Angle Profile Correction for T1 and T2 Quantification with Look-Locker Inversion Recovery 2D SSFP Imaging

摘要

Fast methods using balanced steady-state free precession (SSFP) have been developed to reduce the scan time of T1 and T2 mapping. However, flip angle (FA) profiles created by the short RF pulses used in SSFP deviate substantially from the ideal rectangular profile, causing T1 and T2 mapping errors. The purpose of this study was to develop a FA profile correction for T1 and T2 mapping with Look-Locker 2D inversion recovery SSFP and to validate this method using 2D spin echo as a reference standard. Phantom studies showed consistent improvement in T1 and T2 accuracy using profile correction at multiple FAs. Over six human calves, profile correction provided muscle T1 estimates with mean error ranging from excellent (−0.6%) at TR/FA = 18 ms/60° to acceptable (6.8%) at TR/FA = 4.9 ms/30°, while muscle T2 estimates were less accurate with mean errors of 31.2% and 47.9%, respectively.