Retrieving Issue of Identifying Semantic Relation between Atomic Medical Terms in Noun-noun Compounds in Reports of Computerized Tomography

Abstract

 Background: For the automatic retrieval of medical terms from clinical documents, the problems still remain in processing the noun-noun compounds. In addition, the semantic relations extracted from the compounds are useful for building the ontologies in the domain. Purpose: The purpose of the study is to investigate the distribution of the semantic relations between the two atomic medical terms of the noun-noun compounds extracted from the clinical documents. Methods: 100 clinical reports for CT examination generated in July 2005 were collected in a random way at Hokkaido University Hospital. The medical noun-noun compounds were extracted from the reports. We indexed the UMLS semantic type, group for each atomic medical term in the compounds, extracted the UMLS semantic relation according to the index, and analyzed the distribution of the semantic relations. Results: Only 29.9% of the compounds had the UMLS semantic relation defined (mainly including “location_of” and “adjacent_to”), and 70.1% of them undefined. Conclusion: The semantic relations defined in the UMLS are not enough for the noun-noun compounds extracted from the clinical reports, indicating further efforts are needed.