Contained by and part of

The two hierarchies over anatomic locations, kept separate because they answer different questions.

• Contained by: “physically contained in (e.g., kidney in the retroperitoneum).”¹
• Part of: “a component of a larger structure/system (e.g., adnexa part of female genital system).”¹

Containment is the primary axis. The curated set is “organized into a directed, rooted tree hierarchy, starting from the whole body and ramifying through body regions,” and containment is required on every node while part-of is optional.² Part-of carries organ-system membership, which is why a structure can be contained in one region and part of a system that spans several.

The newer package materializes both. A location carries containment_path, containment_parent, containment_depth, and containment_children, and the same four fields again with a partof_ prefix, so ancestors and descendants on either axis resolve without walking the graph at query time.³

Synonyms and near-synonyms

• containedById and partOfId are the field names in the original JSON file.
• Containment hierarchy and part-of hierarchy are the usual long forms.
• Is-a is neither of these. It is subtype classification, used for FindingClass taxonomies, not for anatomy.
• Part_Of and Has_Part are the RadLex OWL properties that express anatomy inside the ontology itself.

Identifier form

None. Both are references to other RadLex RIDs.

Where it is used

Data model, Tooling, and RadLex integration.

Conflicts

RadLex itself expresses anatomy through Part_Of and Has_Part restrictions and has no separate physical-containment axis, so the containment hierarchy is a curation product rather than something the source ontology supplies. IHE IDR’s query design assumes “fuzzy matching over an anatomical tree” so that a query for liver finds the caudate lobe, without saying which of the two axes that tree is.⁴

Footnotes

1. anatomiclocations.org data file description ↩ ↩²

2. anatomiclocations.org site homepage ↩

3. Containment and part-of fields in the anatomic-locations package ↩

4. IHE IDR Phase II extract ↩