T1 Error Analysis for Double Angle Technique and Comparison to Inversion Recovery B-SSFP Look-Locker Acquisition

Neville D. Gai¹, John A. Butman

The dual flip angle technique (DAT) with short TRs is widely used to derive T1 maps rapidly. DAT offers a relatively faster alternative to typical Look-Locker based schemes. The optimal flip angles required, the effect of field inhomogeneity and, more recently, the effect of spoiling for DAT have been described in literature. In this work, we systematically study various sources of errors through simulations and error propagation analysis. DAT accuracy and repeatability of T1 calculations is shown to be substantially affected as a result of these sources of errors especially when compared with inversion recovery based schemes. Experimental results in phantoms and head scans in several volunteers confirm relatively poorer repeatability and accuracy in calculated T1 values especially when compared with recently described rapid Look-Locker technique with similar temporal and spatial resolution.