Table 2.
Layer-by-layer description of the CNNs used in the two ensemble models SEG and noSEG
Name | Layer | Filter kernel (shape, count) | Output size | ||
---|---|---|---|---|---|
Main branch | Shortcut | noSEG | SEG | ||
in | Input | - | 50 × 50 × 50 × 1 | 50 × 50 × 50 × 2 | |
res1a | 3D convolution | 3 × 3 × 3, 16 | 3 × 3 × 3, 1 | 25 × 25 × 25 × 16 | |
res1b | 3D convolution | 3 × 3 × 3, 16 | id | 25 × 25 × 25 × 16 | |
add1 | Add | - | 25 × 25 × 25 × 16 | ||
res2a | 3D convolution | 3 × 3 × 3, 32 | 3 × 3 × 3, 1 | 13 × 13 × 13 × 32 | |
res2b | 3D convolution | 3 × 3 × 3, 32 | id | 13 × 13 × 13 × 32 | |
add2 | Add | - | 13 × 13 × 13 × 32 | ||
res3a | 3D convolution | 3 × 3 × 3, 64 | 3 × 3 × 3, 1 | 7 × 7 × 7 × 64 | |
res3b | 3D convolution | 3 × 3 × 3, 64 | id | 7 × 7 × 7 × 64 | |
add3 | Add | - | 7 × 7 × 7 × 64 | ||
pool | Global average pooling | - | 64 | ||
drop | Dropout | - | 64 | ||
out | Fully connected layer | - | 1 |
The convolutional part of each network (up to layer “add3”) consisted of a main branch, containing three-dimensional convolutions, and a shortcut branch, containing either a single convolution kernel for downscaling or an identity mapping (“id”). At each add layer (“add1”, “add2”, “add3”), the main branch and the shortcut branch were added. After add1 and add2, the images were split up again into main and shortcut branches