Figure 1:

Overview of the proposed scheme. Bolus tracking starts before the bolus injection. Real-time center frequency calibration (‘CF Cal’) based on a slab FID is triggered upon ROI bolus arrival, while Bloch-Siegert B₁ mapping and real-time ROI B₁ calibration (‘B₁ Cal’) are triggered at the ROI bolus peak. The sequence triggered after B₁ calibration for most experiments in this study is alternate pyruvate/lactate dynamic imaging, and could be replaced by any hyperpolarized ¹³C sequence for other studies.