Abstract #2837

No Inversion Double Angle Look-Locker (NiDALL) for Flip Angle Mapping

Trevor Wade^1,2, Charles McKenzie^1,3, Brian Rutt⁴

¹Imaging Research Laboratories, Robarts Research Institute, London, ON, Canada; ²Biomedical Engineering, The University of Western Ontario, London, ON, Canada; ³Medical Biophysics, The University of Western Ontario, London, ON, Canada; ⁴Diagnostic Radiology and Richard M Lucas Center for Imaging, Stanford University, Stanford, CA, United States

The double angle Look-Locker method is an efficient 3D method of mapping transmit B1 inhomogeneity. It makes uses inversion pulses and samples the recovering magnetization using SPGR trains at two different angles. This leads to two time constants that can be combined to find the achieved flip angle. If the SPGR trains at the two angles are interleaved the inversion pulses can be omitted entirely, and the same information can still be extracted. This reduces SAR, simplifies data analysis and still yields nearly the same performance in terms of measuring the flip angle.