IDEAL spiral CSI for dynamic metabolic MR imaging of hyperpolarized [1-13C]pyruvate

Metabolic imaging with hyperpolarized [1-13C]pyruvate offers the unique opportunity for a minimally invasive detection of cellular metabolism. Efficient and robust acquisition and reconstruction techniques are required for capturing the wealth of information present for the limited duration of the hyperpolarized state (similar to 1 min). In this study, the Dixon/IDEAL type of waterfat separation is expanded toward spectroscopic imaging of [1-13C]pyruvate and its down-stream metabolites. For this purpose, the spectralspatial encoding is based on single-shot spiral image encoding and echo-time shifting in between excitations for the chemical-shift encoding. In addition, also a free-induction decay spectrum is acquired and the obtained chemical-shift prior knowledge is efficiently used in the reconstruction. The spectralspatial reconstruction problem is found to efficiently separate into a chemical-shift inversion followed by a spatial reconstruction. The method is successfully demonstrated for dynamic, multislice [1-13C]pyruvate metabolic MR imaging in phantom and in vivo rat experiments. Magn Reson Med, 2012. (C) 2011 Wiley Periodicals, Inc.