Image Registration
In medical applications, multiple images are acquired from the same subject at different times or from different subjects. The critical stage for utilizing these images is to align them in order to visualize the combined information. Image registration includes the processing to resolve the mapping between images so that the features or structures in one image correspond to those in the other image. The transformation between two image scenes can be of either rigid or non-rigid. Rigid body transformation has six degrees of freedom in three dimensions, i.e. three translations and three rotations. For most body organs, the motion is non-rigid and requires more degrees of freedom to accurately describe tissue motion. Therefore, deformable registration becomes necessary for many image applications. One example is the registration of pre- and post-contrast enhanced breast MRI images. Deformable registration is required for this application as soft tissue, such as breast tissue, always undergoes non-rigid motion between images. Other similar applications can be found during medical imaging diagnosis where different modality images or the same modality at different times, are acquired and require deformable registration because of the non-rigid tissue deformation between images. Examples include heart imaging and chest PET-CT imaging where non-rigid motion can be a major tissue motion source. In image-guided radiation therapy, because of the type of treatment or patient respiration, a non-rigid shape or position change in an organ is unavoidable. Deformable image registration is critical for delivering an appropriate radiation dose and in order to avoid the damage to adjacent healthy tissue. An example is image-guided radiation therapy of prostate tumors or tumors in other organs.
• Thin-plate spline (TPS) deformable image registration• B-spline deformable image registration
• Finite element model-based deformable registration
• Two-dimensional (2D) image registration software
• Three-dimensinal (3D) image registration software
• 3D to 2D Registration
• Slice to Volume Registration
Image Classification
Image Segmentation
Attenuation Correction
Partial Volume Correction
Motion Correction