Coordinate systems, transformations as annotations
For a given anatomical resource (image or mesh or cad) there will be an inherent coordinate system, e.g. coordinate system at birth, where all spatial coordinates are defined. It will be useful to have a place to augment this by annotations, e.g. coordinate system units, provenance to other resources (e.g. image), etc.
Related, an annotation place to store a transformation matrix (or matrices) to relate this local inherent coordinate system to a common coordinate system (for assembly of multiple parts) will be useful for future studies when resources need to be aligned (e.g. by registration) or a cad part may need to be imported, positioned and oriented.
Related, the possibility to store additional local coordinate system(s) as annotations/attributes, i.e. as transformation matrix from the inherent coordinate system, will be beneficial. These local coordinate systems can be related to anatomical landmarks (e.g. node selections on the body that are labeled accordingly).