Extra‐dimensional Demons: A method for incorporating missing tissue in deformable image registration

Abstract

Adaptation of the Demons deformable registration process to include segmentation (i.e., identification of excised tissue) and an extra dimension in the deformation field provided a means to accurately accommodate missing tissue between image acquisitions. The extra-dimensional approach yielded accurate "ejection" of voxels local to the excision site while preserving the registration accuracy (typically subvoxel) of the conventional Demons approach throughout the rest of the image. The ability to accommodate missing tissue volumes is important to application of CBCT for surgical guidance (e.g., skull base drillout) and may have application in other areas of CBCT guidance.

Getting the most out of additional guidance information in deformable image registration by leveraging multi-objective optimization

“…In contrast with other work [5][6][7][8][9][10] , in our work the challenging problem of identifying (dis)appearing structures between image acquisitions has been considered to be part of the overall optimization process. Although this removes the need to manually fully identify (dis)appearing structures, the images themselves do not always provide sufficient information for the problem to be solved without additional guidance information.…”

Deformable Image Registration for Adaptive Radiation Therapy of Head and Neck Cancer: Accuracy and Precision in the Presence of Tumor Changes

“…Algorithms, such as finite element model (25) and the extra-dimensional Demons proposed by Nithiananthan et al (26), in which segmentation and registration are performed simultaneously, account for the disappearing tissues. However, tumor variation is difficult to model, and if there is insufficient contrast, the tumor is difficult to segment.…”

Deformable image registration by multi-objective optimization using a dual-dynamic transformation model to account for large anatomical differences

“…Furthermore, when the focus is on intra-operative guidance, the assumption is used that disappeared tissue has been replaced by "air". 7 This will, however, not always be the case. For example in the case of breast-conserving surgery for breast cancer, the excision cavity is often closed for an improved cosmetic result.…”

“…due to tissue excision between image acquisitions). [2][3][4][5][6][7] Moreover, in these works the identification of the disappearing structures is considered a separate task, often as part of segmentation. Furthermore, when the focus is on intra-operative guidance, the assumption is used that disappeared tissue has been replaced by "air".…”