Imaging Hyperpolarized Substrates
Dynamic nuclear polarization of 13C-enriched substrates such as [1-13C]-pyruvate enhances signal strength by four orders of magnitude or more, enabling real-time assessment of key aspects of metabolism in vivo with unprecedented spatiotemporal resolution and chemical specificity. Dynamic MRI to assess the conversion of HP pyruvate into lactate is of particular interest in oncology because it is an indicator of altered metabolism (aerobic glycolysis, or the “Warburg effect”) that is associated with many cancers and is affected by a variety of approaches to therapy. Imaging of HP substrates is challenging because magnetization is transient, non-renewable, and depleted by the very act of measurement. We have partnered with a wide variety of physicians and scientists to understand the challenges and opportunities of this exciting new modality, the unprecedented insight it provides into tumor metabolism, and the role it will play in research and in care for patients affected by cancer.
Adapted from: Bankson JA, Walker CM, Ramirez MS, Stefan W, Fuentes D, Merritt ME, Lee J, Sandulache VC, Chen Y, Phan L, Chou P-C, Rao A, Yeung S-C, Lee M-H, Schellingerhout D, Conrad CA, Malloy C, Sherry AD, Lai SY, Hazle JD. Kinetic Modeling and Constrained Reconstruction of Hyperpolarized [1-13C]-Pyruvate Offers Improved Metabolic Imaging of Tumors. Cancer Res 75(22): 4708-17, 2015.