select a slice in segmentation mask

[YingdiZhang]

Thanks for the great work.
I get stuck in using MONAI. I aquired the segmentation mask of a CT volume, which is '1' for the foreground and '0' for background. and I would like to get the middle slice of foreground in saggital plane. How should I achive this?

[KumoLiu]

Hi, @YingdiZhang

Thank you for using MONAI. I think SpatialCrop transform could help you solve your issue.
Suppose your segmentation mask is named seg_mask. Then you can do like :

center_idx = seg_mask.shape[2]//2  #  shape should be of (C,W,H,D)
center_slice = SpatialCrop(roi_slices=[slice(0, None), slice(center_idx, center_idx+1), slice(0, None)])(seg_mask)