FIGURE 2.

Virtual Sampling protocol. (A) Here we show the cortical samples routinely taken at autopsy on coronal sections of fixed human brain that are oriented by anatomic convention (MFG, middle frontal gyrus; MSTG, middle and superior temporal gyri; IPL, inferior parietal lobule; V1, primary visual cortex. For traditional neuropathologic sampling, the neuropathologist targets the regions of interest (ROIs; open black boxes) using the gyral pattern and deep brain structures as landmarks on the sliced human brain. (B) To mimic traditional neuropathologic sampling in silico, we generated coronal slices using each subject’s native space T1-weighted MRI. An example subject is shown in radiological convention. The neuropathologist identified the ROIs on the MRI slices (subject-specific samples; red) using the same gyral patterns and deep brain structures as would be used in physical brain slices. (C) The MNI space template brain was then used to create similar coronal slices and ROIs were identified as before (target samples, green boxes). (D) Finally, the ROIs identified on the coronal sections of the MNI space template brain were aligned to each subject’s T1-weighted MRI (reference samples, light green). A series of adjacent 4 mm thick coronal sections from a single subject’s native space T1-weighted MRI illustrates the variability between the subject-specific and reference samples.