Deformation Simulation
To implement image deformation, the correlated stochastic field [In such a Gaussian random field, the probability for the field at location × 1 would have a value of In which In which The simulated deformation field moves all regions with the same strength. To add anatomical considerations, the field strength in bony structures and air (outer body) regions was decreased using regional information and a smoothed correction map. Afterward, the rectum expansion simulation was added, which is a random expansion modulated on the general deformation field. For the deformation offset field, a sigma (Synthetic image deformation workflow. From left to right: input CT image was considered a fixed image, the binary masks of the key organs (created from the RT structure data) were defined on the fixed image, a non-linear deformation was applied on the binary mask, and subsequently, a deformed CT image was created from the deformed binary masksAs shown in Fig. First row: original and deformed images. Second row: original and deformed masks. Third row: original and deformed grids/fields