Figure 6:

Results of two hyperpolarized [1-¹³C]pyruvate studies in a normal rat using the proposed method (Fig. 1) with a ¹³C surface transceiver coil. The two experiments were performed with the same parameters except for different tracking/calibrating ROIs: experiment #1 on right kidney and #2 was on left kidney, where the left kidney is closer to the coil. Injection time was 10 s and initial power was the same as the calibrated power in pre-scan. Sequence parameters are presented in Table 1. (a) Proton localizer. (b) Normalized ¹³C B₁ maps. B₁ maps acquired in two experiments are consistent. (c) Estimated k_PL with and without flip angle correction based on measured B₁ map. k_PL values for left kidney, right kidney and intestine are labeled in the maps. Using acquired B₁ maps to correct flip angle results in more consistent k_PL estimations of those ROIs between the two experiments, demonstrating the importance of flip angle correction for k_PL measurements. Experiment recordings: https://youtu.be/Mu3NW7Kog9M, https://youtu.be/fL5gVkPDw2o.