29. Hyperpolarized 13C pyruvate mouse brain metabolism with absorptivemode EPSI at 1 T
Vesselin Z. Miloushev, Valentina Di Gialleonardo, Lucia Salamanca-Cardona, Fabian Correa, Kristin L. Granlund, Kayvan R. Keshari, Journal of Magnetic Resonance, (2017), 275, 120-126, DOI: 10.1016/j.jmr.2016.12.009
The expected signal in echo-planar spectroscopic imaging experiments was explicitly modeled jointly in spatial and spectral dimensions. Using this as a basis, absorptive-mode type detection can be achieved by appropriate choice of spectral delays and post-processing techniques. We discuss the effects of gradient imperfections and demonstrate the implementation of this sequence at low field (1.05 T), with application to hyperpolarized [1-13C] pyruvate imaging of the mouse brain. The sequence achieves sufficient signal-to-noise to monitor the conversion of hyperpolarized [1-13C] pyruvate to lactate in the mouse brain. Hyperpolarized pyruvate imaging of mouse brain metabolism using an absorptive-mode EPSI sequence can be applied to more sophisticated murine disease and treatment models. The simple modifications presented in this work, which permit absorptive-mode detection, are directly translatable to human clinical imaging and generate improved absorptive-mode spectra without the need for refocusing pulses.