32.5 Synthetic MR Brain Image Experiments
In this section, a series of experiments were conducted via synthetic images to substantiate the utility of OC-ICA in MR image analysis and to demonstrate its advantages over the traditional ICA.
The synthetic images to be used for experiments in this section are the axial T1, T2, and proton density MR brain images (with 5-mm section thickness, 0% noise, and 0% intensity nonuniformity) resulting from the MR imaging simulator of McGill University, Montreal, Canada (available at www.bic.mni.mcgill.ca/brainweb/). The image volume provided separate volumes of tissue classes, such as CSF, GM, WM, bone, fat, and background. The use of these web MR brain images is to allow researchers to reproduce our experiments for verification. Figure 32.2(a) shows three MR brain images with provided specifications where the first image is obtained by modality = PD, protocol = ICBM, phantom_name = normal, slice_thickness = 5 mm, noise = 0%, INU (intensity nonuniformity) = 0%, the second image by modality = T1, protocol = ICBM, phantom_name = normal, slice_thickness = 5 mm, noise = 0%, INU = 0%, and the third image by modality = T2, protocol = ICBM, phantom_name = normal, slice_thickness = 5 mm, noise = 0%, INU = 0%. Figure 32.2(b) provides the ground truth also available on website www.bic.mni.mcgill.ca/brainweb/ for brain tissue substances in the images in Figure 32.2(a), which will be used to verify the results obtained for our experiments.