Figure 2.

In vitro phantom design and obtained time-of-flight (TOF) ¹²⁹Xe curves with Pearson’s correlation coefficient. (a) Schematic diagram of the flow phantom used in this study. A syringe pump provided four different flow rates, i.e., 5 mL/min, 6 mL/min, 7 mL/min, and 10 mL/ min. (b) ¹²⁹Xe TOF recovery curves were measured using the TOF imaging approach. A difference in flow rate of 1 mL/min created well-detected differences in the TOF curves. A quasilinear region was observed between 200 ms and 700 ms. A nonlinear recovery appeared for longer recovery times, followed by a steady state. (c) Pearson’s linear correlation between the flow rate and the slopes of the TOF curves was calculated at the quasilinear region. A strong positive correlation (r ≈ 0.988) was observed, indicating the potential to use this slope for flow mapping.