Image registration aligns corresponding anatomical structures in the CT and MRI datasets so that information from both modalities refers to the same spatial locations. The alignment may use rigid transformations or deformable transformations, depending on how the anatomy must be matched. Accurate registration is therefore central to producing a combined representation that can be interpreted reliably.
CT contributes high-resolution information about bone and tissue density, whereas MRI provides detailed soft-tissue contrast. Their complementary strengths allow clinicians to examine structures that may not be characterized equally well by either modality alone. Fusing the datasets supports joint interpretation, especially when both bony landmarks and soft-tissue detail are relevant to anatomical assessment.
Rigid and deformable transformations provide different ways to match anatomy between the two image datasets. A rigid transformation is appropriate when corresponding structures can be aligned without changing their relative arrangement. A deformable transformation accommodates more complex matching requirements by allowing the registration to represent differences in anatomical configuration, supporting more precise spatial correspondence.
A typical workflow begins with CT and MRI image datasets that depict the anatomy of interest. The datasets are then registered by matching corresponding structures through a rigid or deformable transformation. After alignment, the images can be overlaid or integrated into a shared representation for joint interpretation, planning, or guidance in a clinical procedure.
In radiotherapy planning, fused images can combine CT information about bone and tissue density with MRI information about soft-tissue contrast. This combined view may support more detailed tumor localization and target definition than either dataset considered in isolation. The resulting anatomical information can contribute to treatment planning and potentially improve treatment precision.
The technique is useful when image-guided surgery requires both detailed soft-tissue information and high-resolution depiction of bone or tissue density. It also supports assessment of complex anatomy by placing complementary findings into a spatially aligned view. These applications can help clinicians localize relevant structures and interpret anatomical relationships during planning or image-guided work.