Kees M. van Hespen1, Dirk H.J. Poot1,2, Harm A. Nieuwstadt1, and Stefan Klein1
1Departments of Medical Informatics and Radiology, Erasmus MC, Rotterdam, Netherlands, 2Imaging Science and Technology, Delft University of Technology, Delft, Netherlands
We have recently developed an
optimized T1 mapping protocol for carotid atherosclerotic plaque imaging, using
a combination of inversion and recovery prepared acquisitions. This protocol requires
less images to be taken (and thus shorter acquisition time) for precise T1 estimation
than conventional inversion-prepared or saturation-prepared acquisition
schemes. However, estimating T1 from magnitude data, acquired with the
optimized settings, causes bimodality of T1 estimates, due to the ambiguity in
sign of the inversion prepared magnitude images. Simulations and experiments on
a hardware phantom and a volunteer show that the ambiguity resolves when we fit
a complex-valued model to the complex data.
