Flip angle profile correction for T sub(1) and T sub(2) quantification with look-locker inversion recovery 2D steady-state free precession imaging

• Published in: Magnetic resonance in medicine 2012-11, Vol.68 (5), p.1579-1585
• Main Authors: Cooper, Mitchell A, Nguyen, Thanh D, Spincemaille, Pascal, Prince, Martin R, Weinsaft, Jonathan W, Wang, Yi
• Format: Article
• Language: English
• ISSN: 0740-3194; 1522-2594
• DOI: 10.1002/mrm.24151

Fast methods using balanced steady-state free precession have been developed to reduce the scan time of T sub(1) and T sub(2) mapping. However, flip angle (FA) profiles created by the short radiofrequency pulses used in steady-state free precession deviate substantially from the ideal rectangular profile, causing T sub(1) and T sub(2) mapping errors. The purpose of this study was to develop a FA profile correction for T sub(1) and T sub(2) mapping with Look-Locker 2D inversion recovery steady-state free precession and to validate this method using 2D spin echo as a reference standard. Phantom studies showed consistent improvement in T sub(1) and T sub(2) accuracy using profile correction at multiple FAs. Over six human calves, profile correction provided muscle T sub(1) estimates with mean error ranging from excellent (-0.6%) at repetition time/FA = 18 ms/60 degree to acceptable (6.8%) at repetition time/FA = 4.9 ms/30 degree , while muscle T sub(2) estimates were less accurate with mean errors of 31.2% and 47.9%, respectively. Magn Reson Med, 2012. copyright 2012 Wiley Periodicals, Inc.