Figure 8.

Liquid-state ¹³C polarization of [1-¹³C]pyruvate obtained from hyperpolarized [1-¹³C]pyruvic acid (neat) doped with trityl radical (15 mM - 26 mM) as a function of B₀/T, back-calculated to the time of the dissolution. Five data points (blue circles) were used for the linear fit (least square method) shown in blue: (1) estimated mean ¹³C polarization obtained with HyperSense™ (3.35 T, 1.4 K); (2) reported ¹³C polarization obtained using the original hyperpolarizer by Chen et al. (3.35 T, 1.2 K)²⁵; (3) estimated mean ¹³C polarization obtained with SPINlab™ (5 T, 0.8 K); (4) reported ¹³C polarization obtained by Yoshihara et al. (7 T, 1 K)²¹; (5) reported ¹³C polarization obtained by Jähnig et al. (7 T, 1.4 K)²³. Two additional data points are displayed: (black circle) reported ¹³C polarization obtained by Ardenkjaer-Larsen et al. (6.7 T, 1.4 K)¹⁵; (red circle) ¹³C polarization reported in the present work (7 T, 1.35 K).