Figure 7.

Percent increase in BP_ND estimated from human [¹¹C]flumazenil data using Reference compared to Standard weighting as a function of relative region size. Fractional change was averaged across all 33 scans for each of the 33 uniquely sized brain regions. The trend toward greater effect of Reference weighting for larger target region volumes is consistent with findings of the simulation studies. The linear regression fit was y = −0.25x+0.34 and, though not strictly valid over a wider range region sizes, adequately described the relationship with a correlation coefficient of r = 0.69.