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Abstract #4561

A Simplified Nonlinear Fitting Strategy for Estimating T1 from Variable Flip Angle Sequences

Joshua Trzasko1, Petrice M. Mostardi1, Stephen J. Riederer, Armando Manduca1

1Mayo Clinic, Rochester, MN, United States


Variable flip angle SPGR imaging, despite challenges due to transmit field inhomogeneities, remains a widely used strategy for T1 mapping. Nonetheless, there has been little work on numerical strategies for computing T1 values from such image series, and most estimations are performed using either a two-parameter nonlinear least squares fitting, which is accurate but computationally intensive, or a linear regression approximation, which is significantly faster but prone to error. In this work, we describe a simple numerical optimization strategy which can accelerate NLLS computation by over an order of magnitude without compromising its accuracy.