Laterality
Whether a structure or a finding is left, right, or neither. The curated anatomic sets represent it structurally: “for cases where the body part is sided, the index contains three versions: an unsided version, a left-sided version, and a right-sided version. All of these are aware of each other.”1 The newer package makes this an enumeration with four values, generic for a structure that has left and right variants, left, right, and nonlateral for a structure with no sides at all such as the heart or the spine.2
Assigning laterality to a finding follows a stated precedence: explicit side in the text beats a sided exam, which beats the generic unsided structure. A non-sided exam never introduces a side. Laterality must be resolved “against the full report section, not the finding’s isolated quote,” because the side is often stated only in a section header or an earlier sentence, and a side is never inferred across exams or from clinical priors.3
Bilateral findings split or do not split by a stated test. Discrete independent lesions per side become two findings; a single diffuse entity named as one, an “-osis” or a “disease,” stays generic and unsided. The operational test is whether “you could meaningfully say the left one is larger or newer.”3
Synonyms and near-synonyms
- Sidedness and side are informal equivalents.
- Unsided, generic, and nonlateral are not interchangeable: generic means sides exist but none is specified, nonlateral means the structure has no sides.
- Bilateral is an assertion about a finding, not a laterality value on a structure.
Identifier form
In the original set, sided variants take composite identifiers such as RID294_RID5824. In the newer package, laterality is an enum field with left_variant, right_variant, and generic_variant references.
Where it is used
Laterality conventions, Data model, and Anatomic location assignment rules.
Conflicts
IHE IDR keeps laterality in a separate FHIR field on an unsided structure code, while OIDM’s anatomy nodes are themselves sided. The IDR extract lists a stated mapping between the two, sided identifier and unsided identifier plus laterality, as something still needed so both directions round-trip.4 A known defect in the findingmodel issue list also reports that laterality is assigned backwards during one database build step.