RadLex Chair Orientation Meeting July 19, 2005

1. RadLex Chair Orientation MeetingJuly 19, 2005 What is a Controlled Medical Terminology DONALD P. HARRINGTON MD,MA

2. Outline of Discussion • Background and Motivation • Definition of terms • Index’s, Classifications and Terminologies • Why do we need a Controlled Medical Terminology • What constitutes a Controlled Medical Terminology • Cimino’s desiderata • Framework for a Comprehensive Health Terminology Systems. Chute et.al. • Sources of terms MedLEE

3. Definitions • Vocabulary: all the words used by or known to a particular person or group, or contained in a language as a whole • Lexicon: the entire stock of words belonging to a branch of knowledge or known by somebody • Terminology: the expressions and words, or a set of expressions and words, used by people involved in a specialized activity or field of work

4. Definitions • Index: 1. An order list of the items that make up a set 2. An alphabetical list, usually at the end of a book, of people places, or topics, giving the numbers of the pages on which they are mentioned • Classification: 1. the allocation of items to groups according to type 2. The categorization of organisms into defined groups on the basis of identified characteristics.

5. Problem? • The English Language is extraordinarily expressive but is by the same token filled with vagueness, ambiguity and ellipsis • There is no reporting standard • There is no standardized teaching of reporting

6. Problem? • Radiological reporting is not an exact science • Radiological interpretation is a subjective process and this subjectivity compounds the problem of vagueness and ambiguity • There is uncertainty in the diagnostic process and this is poorly specified if at all

7. Why we need a Controlled Radiology Vocabulary We need to improve our human to human communication. We must establish machine to machine communications to take full advantage of PACS and Digital Imaging. We need a standard vocabulary to accomplish the above

8. Why Do we need machine to machine communication • To facilitate and to complete the Electronic Medical Record • Reduction in Medical Error • Facilitates Data Mining • Epidemiology studies and bioterrorism detection • Teaching file development and use • Application of Decision Support to Imaging • Image Interpretation • Differential Diagnosis

9. Terminology Development and Cimino’s Desiderata • Content,Content and Content • Concept Orientation • Concept Permanence • Nonsemantic Concept Identifiers

10. Cimino’s Desiderata • Content,Content and Content • This is the focus of the domain experts that make up this group and others that will follow. • Curt has included terms from the ACR Index, other knowledge bases such as Medical texts and indices of disease • I believe a portion of the terms can come from the output of MedLee from Columbia Radiology reports.

11. Cimino’s Desiderata • Concept Orientation • This means that terms must correspond to at least one meaning (nonvagueness) and no more than one meaning (nonambiguity) and that meanings correspond to no more than one term (nonredundancy)

12. Cimino’s Desiderata • Concept Permanence • Old terms are retired but not dropped • Nonsemantic Concept Identifiers

13. Cimino’s Desiderata • Polyhierarchy • Formal Definitions • Reject “Not Elsewhere Classified “ • Multiple Granularities

14. Cimino’s Desiderata • Polyhierarchy • Anatomy and Pathology Fig. 1 • Formal Definitions • “is a “, “part of”. Fig. 2 • Reject “Not Elsewhere Classified “ • Multiple Granularities • ICD-9 vs. DRG

15. Cimino’sDesiderata • Multiple Consistent Views • Different tracks lead to the same concept • Beyond Medical Concepts Representing Context Fig. 2 • Evolve Gracefully [Things change] • Recognize Redundancy [synonyms]

16. A Framework for Health Terminology systems in the US • General • Completeness: Explicit in-depth coverage • Comprehensiveness: All aspects of the subject • Characteristics of integration: Unique term representation • Nonoverlapping: Specialized terminology is nonredundent and interrelates with existing systems • Integrated: Cross-referenced to the the point of interdependence

17. A Framework for Health Terminology systems in the US • General • Nonredundent: Internally consistent with one and only one preferred way to represent a concept or idea • Mapping: An algorithmic relationship with classifications such as ICD-9 and CPT Codes. This could relate to language translation

18. A Framework for Health Terminology systems in the US • Structure of the terminology model • Atomic base: Root concept • Compositional: Root concepts are combinable • Synonyms: Are to be made explicit and supported likewise, abbreviations and non-English terms • Attributes Time, staging, quantity • Inheritance

19. A Framework for Health Terminology systems in the US • Structure of the terminology model • Multiple hierarchies: • Terms have multiple semantic parents • Lung cancer is a in the neoplasm and the lung disease hierarchy • Consistency of views: Both hierarchies lead to the same concept--lung cancer • Explicit uncertainty: • The lack of expression for uncertainty is a major flaw in Radiology reporting • Lexical rules: Spell checking • Representation: No restriction on coding of concepts

20. A Framework for Health Terminology systems in the US • Maintenance • Context-free identifiers • Unique identifiers • Version control • Dated • Obsolete marking • Definitions • Language independence • Responsiveness

21. A Framework for Health Terminology systems in the US • Administration • Coordination • Access • Funding