Semantic distribution study of noun*noun compounds in the Japanese CT clinical reports.

The purpose of this study is to investigate the distribution of the semantic relationships between the two atomic medical terms of the noun-noun compounds extracted from the clinical documents in Japanese. Only 29.9% of the compounds had the UMLS semantic relation defined (mainly including "location_of" and "adjacent_to"). The results indicated that the semantic relations defined in the UMLS semantic network are not enough for describing the noun-noun medical compounds extracted from the Japanese clinical reports.