Figure 1. Image preprocessing examples (from P-x and LC-A) in quantitative analysis on inter-site heterogeneity. Among the six methods in Table 3, whitening, whitening + BFC, and whitening + NF act as representatives. Coarse lesion region is contoured (in red) on the randomly selected pre-cropped T2 images. Prior to the preprocessing (left half), the heterogeneity of intensity distribution can be observed obviously in the original samples, while the distributions are harmonized after the preprocessing (right half). All the jet color maps are same scale.