Figure 4:

Results of a hyperpolarized [1-¹³C]pyruvate study in a normal rat using the proposed method (Fig. 1) with a birdcage coil. Real-time center frequency calibration was not performed in this study. The ROI for both bolus tracking and B₁ calibration was on the left kidney. Injection time was 8 s and initial power was purposely set to 120% of the calibrated power in pre-scan. Sequence parameters are presented in Table 1. (a) Proton localizer. (b) Normalized ¹³C B₁ map. Real-time B₁ scaling factor (~0.87) matched up with the initial transmit power (120%). (c) Normalized pyruvate signal curves in different ROIs. The ROI (left kidney) bolus peak was successfully detected. (d) ¹³C results displayed in the order of time. Every other timeframe is shown. The full set of images can be found in Sup. Fig. S1. Experiment recording: https://youtu.be/CN3mIrzmBT8.