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

Purpose To 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. Methods Sat‐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. Results Sat‐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. Conclusion The 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. © 2014 Wiley Periodicals, Inc.