Article Figures & Data
Figures
- Fig 1.
Simulated cortical signal change. A, First row (left to right), Representative MPRAGE in a healthy control patient (25-year-old man). Forty percent of voxels through 7 slices within the ROI were randomly selected and used to simulate changes in T1 signal intensity via decreasing and increasing voxel intensity to 20% in increments of 5%. Selected ROI from the frontal operculum for simulating signal change is shown in the original image (white solid line). Second row, Corresponding segmented GM maps in the native space. Third row, mGM maps in the template space and, Fourth row, corresponding cortical boundaries from FreeSurfer. B, High correlation between signal intensity and mGM is observed (black dots [R = 0.964; P < .001]), but no relationship is seen between signal intensity and CT (gray triangles).
- Fig 2.
A 71-year-old man with acute onset weakness of the left upper extremity presented with an area of acute infarction (blue arrow) along the deep posterior cortex of the right precentral gyrus involving the hand motor region, with A, relative hypointensity on MPRAGE, B, hyperintensity on FLAIR, and C, restricted diffusion on the ADC map. The patient also has an area of chronic infarction more anteriorly (red arrow), showing A, relative hypointensity on MPRAGE, B, hyperintensity on FLAIR, and C, T2 shine through on the ADC map. ROIs in the affected areas (D) show higher and lower CT, respectively, compared with contralateral analogous brain (E); however, mGM as a marker of cortical volume was higher in the acute infarct, as expected, but also higher in the chronic infarct.
- Fig 3.
In vivo examples illustrate concordant results between FSL-VBM and FreeSurfer-CT in the ROIs of acute infarct (A) as well as when comparing younger and older healthy control patients (B), and discordant cortical morphometry results in ROIs of chronic infarct (C) and in the precuneus (D) in a patient with mTBI compared with a matched control patient. Of note, prior work reports morphometric changes to the precuneus in aging and traumatic brain injury. The mean values within the ROIs were reported.
