Fig. 9.

Each subplot shows the ROC curves of recognizing the hemoglobin activity difference between two ROIs using the two types of contrast vectors (indicated by color) for data from 2000 iterations of simulations under the conditions where the probe registration information (including head size and registration error) is known or not. The simulated activities are generated within one of the two 10-mm (radius) ROIs separated by 80 mm, and two types of probe, (a) low-density and (b) high-density, are used in the simulation. The column and row of each subplot indicate known/unknown probe registration and oxy-/deoxyhemoglobin, respectively.