Latent shape image learning via disentangled representation for cross-sequence image registration and segmentation

Cross-sequence magnetic resonance image (MRI) registration and segmentation are two essential steps in a variety of medical image analysis tasks. And have attracted considerable research interest. However, they remain challenging due to domain shifts between different sequences. This study is aiming at proposing a novel method via disentangled representations, latent shape image learning (LSIL), for cross-sequence image registration and segmentation.

Images from different sequences were firstly decomposed into a shared domain-invariant shape space and a domain-specific appearance space via an unsupervised image-to-image translation approach. A latent shape image learning model is then built on the disentangled shape representations to generate latent shape images. A series of experiments including cross-sequence image registration and segmentation were performed to qualitatively and quantitatively verify the validity of our method. Dice similarity coefficient (DSC) and 95th percentile Hausdorff distance (HD95) were adopted as our evaluation metrics.

The performance of our method was evaluated based on 2 datasets total of 50 MRIs. The experimental results showed the superiority of the proposed framework over the state-of-the-art cross-sequence registration and segmentation approaches. The proposed method shows the mean DSCs of 0.711 and 0.867, respectively, in cross-sequence registration and segmentation.

We proposed a novel method based on representation disentangling to solve the cross-sequence registration and segmentation problem. Experimental results prove the feasibility and generalization of the generated latent shape images. The proposed method demonstrates significant potential for use in clinical environments of missing sequences. The source code is available at https://github.com/wujiong-hub/LSIL .