Figure 4.

Variation of Dslow, CoV-Dslow, PF, Cov-PF, Dfast, and CoV-Dfast with the number of b value (all b value or small b value <100 s/mm²). For Dslow and PF, an increase of the number of total b value or small b value (<100 s/mm²) leads to a decrease of CoV of individual studies. An increase of the number of small b values (<100 s/mm²) and total b values lead to a slight increase Dslow value. An increase of the number of small b values lead to a decrease of PF value, and a substantial increase of Dfast. CoV, coefficient of variation; PF, perfusion fraction.