Figure 2
From: Quantitative lung SPECT applied on simulated early COPD and humans with advanced COPD
Illustration of the area under the curve for CV-values greater than the threshold value CV T . The mean frequency functions of 20 noise realisations of the CV values corresponding to (a) distribution 1, the simulated normal, and (b) distribution 8, ‘2-cm50% 48% evenly.’ CVT was set to 20.5% for the simulated distributions. Indicated in the figure are the calculated AUC(CVT) values for the two distributions.