Fig. 7.

(a) Absolute BF measured by DCE-NIRS technique (vertical axis) compared with the BFI measured with DCS (horizontal axis) across $N=36$ measurements. The black line represents the best linear fit to the data with the intercept forced to be zero ($\text{slope}=(1.24\pm 0.08)\times {10}^9$, $R^2=0.89$, $p<0.01$ with F-test). (b) Bland–Altman plot of the difference in absolute CBF measurements from DCS and DCE-NIRS techniques. The solid horizontal line indicates the mean difference between the two parameters computed across the study population, which is not significantly different from zero ($p=0.47$ with Wilcoxon rank sum test). The dotted line indicates 95% CI limits for agreement. Different colors in (a) and (b) represent different patients.