Figure 5b. Parametric map analysis obtained from series of images shown in Figure 3. Note central arterial canal (arrow) on time-to-peak intensity map. (a) Pixels that reach peak intensity early are represented in red; scale is in seconds. On peak-intensity map, maximum is reached in center of placenta, corresponding to labyrinth region that contains only blood. (b) Red represents pixels that reach highest intensity; scale is in signal intensity.