Table 1:

Overview of the combined algorithm

Algorithm 1: Combined Algorithm
Require: X: CT volume, shape = D × H × W
Require: xi = X(Li), (i=1, .… ,k): CT voxel patch
Require: yi = M(xi): yi is the output of the last layer (softmax activation function) of the model M, yi has 1 more dimension than xi, and this dimension has 3 channels. Each channel refers to the probability of the corresponding voxel belonging to background or bone or nerve, respectively.
1) Initialize: Y ← 0
2) For xiX,(i = 1, … ,k) do
3) Y(Li,:) + = yi
4) End for
5) S ← arg max(Y, axis = −1) (find the channel with the largest value in the last dimension)
6) Return S (the automatic mask)
  • Note:M indicates the model (network); L, location of the CT voxel patch x at the CT volumn X; Y, summed probability; max, maximum.