Simple and robust saturation-based slice selection for ultrashort echo time MRI

PurposeTo present a new method for localizing signal within a two-dimensional (2D) slice suitable for ultrashort echo time (UTE) imaging, called saturation-based UTE (sat-UTE). The new method digitally subtracts two acquisitions that are nonselectively excited with and without selective saturation of the slice of interest. MethodsSat-UTE was compared with half-pulse and double-half pulse excited UTE within phantoms, as well as 3D-UTE within ex vivo femur and in vivo tibia. Numerical simulations were also used to quantify the effects of slice profile broadening and signal component amplitudes for quantitative UTE. ResultsSat-UTE is robust to suppress out-of-slice signal, and produces short T-2 signal decay curves comparable to 3D-UTE, but has a lower signal to noise ratio efficiency compared with other slice-selective methods. ConclusionThe proposed method is useful for fast, quantitative evaluation of short T-2 signals, and is insensitive to gradient performance. Magn Reson Med 73:2204-2211, 2015. (c) 2014 Wiley Periodicals, Inc.