Figure 7.

Temporal subtraction images without voxel matching method (A) (Global Matching, Local Matching, and Elastic Matching) and with voxel matching (B), and the final subtraction image using SuperVoxel based Graph Cuts and support vector machine (C). Ground-glass opacity (GGO; red circle) remains in (A), but there are a lot of artifacts in this image. On the other hand, with voxel matching (B), the artifacts are not noticeable, but the GGO shadow is missing or disappearing. In contrast, in the proposed method using SuperVoxel based Graph Cuts and support vector machine, artifacts are reduced while leaving GGO (C).