Figure 2. Hyperpolarized [1-¹³C] glutamate formation from hyperpolarized [1-¹³C] α-KG can be detected in live cells, and is decreased in U87IDHmut cells as compared to U87IDHwt.

Stack plots of dynamic ¹³C MR spectra acquired at 11.7 Tesla following injection of hyperpolarized [1-¹³C] α-KG in live U87IDHwt (A) and U87IDHmut (B) perfused cells (temporal resolution 9 seconds), showing the formation of hyperpolarized [1-¹³C] glutamate in U87IDHwt cells. Note the absence of detectable hyperpolarized [1-¹³C] glutamate in U87IDHmut cells. (C) Intensities of hyperpolarized [1-¹³C] glutamate in U87IDHwt (□) and U87IDHmut ( ) perfused cells, showing the significantly higher level of glutamate in U87IDHwt cells as compared to U87IDHmut. Also of importance is the delayed formation of hyperpolarized [1-¹³C] glutamate versus the time of maximum hyperpolarized [1-¹³C] α-KG (vertical dashed line), as expected when metabolism occurs. The fit derived from the gamma-variate analysis (GVA) is displayed as a continuous line for U87IDHwt and as a dashed line for U87IDHmut perfused cells.