Article Figures & Data
Figures
- FIG 1.
The VAE network and an input/output sample pair from the ISLES data set. X denotes the input data; Z denotes its low-dimensional latent representation. The VAE consists of an encoder network that computes an approximate posterior qφ (Z|X), and a decoder network that computes pθ (X|Z). The VAE model takes T1, T2, and FLAIR images from individual subjects (left), compresses them to generate a latent representation (Z), and regenerates 3 images (right). The VAE is trained on a data set that contains few lesions. After training, when presented with a newly lesioned brain, the reconstruction effectively removes the lesion from the image, resulting in a normal (lesion-free) version of the brain.
- FIG 2.
Three orthogonal views through the P values thresholded at P = .05 (FDR-corrected) obtained for the F-test for TBM analysis using Jacobian determinants. L indicates left; R, right.
- FIG 3.
Reconstruction results obtained by applying the VAE to the ISLES data set. A, Sample slices from input images. B, Slices reconstructed from the VAE. C, Difference between input and reconstructed images. D, Error maps after applying median filtering to reduce the occurrence of spurious voxels. E, Manually delineated lesion masks used as ground truth to evaluate VAE performance.
- FIG 4.
Orthogonal views through the P values thresholded at P = .05 (FDR-corrected) obtained for the F-test comparing lesion maps for the PTE and non-PTE groups. L indicates left; R, right.
Tables
Lobe-wise lesion volumes as measured using a 1-class SVM to generate binary lesion maps
Lobe Percentages of Lobe Volumes in Subjects with PTE (mean, median [SD]) Percentages of Lobe Volumes in Subjects without PTE (mean, median [SD]) P Value (F-Test) Right temporal 5.267, 4.746 [1.496] 4.888, 4.803 [0.819] .003a Left temporal 5.267, 4.993 [1.223] 4.924, 4.871 [0.7661] .02a Right occipital 4.739, 4.131 [1.749] 4.817, 4.724 [1.225] .05a Left occipital 4.472, 4.336 [1.358] 4.658, 4.384 [1.001] .08 Right frontal 5.223, 4.794 [1.416] 5.456, 4.897 [1.868] .95 Left frontal 5.513, 5.251 [1.646] 5.342, 5.016 [1.399] .31 Right parietal 5.113, 4.756 [1.353] 5.197, 4.999 [1.337] .65 Left parietal 4.943, 4.610 [1.183] 5.134, 4.859 [1.320] .82 Right insula 5.524, 5.319 [1.259] 5.205, 5.147 [1.383] .65 Left insula 5.229, 5.082 [1.067] 4.797, 4.612 [1.045] .82 Cerebellum 5.130, 4.758 [1.269] 5.117, 5.046 [0.8524] .03a Note:—SVM indicates support vector machine.
↵a Cases of significant differences in the variance of lesion volume between PTE and non-PTE (F-test). the FDR-corrected P values are shown at a significance level of α = .05. We report both mean and median lesion volumes.
