Abstract
The informational content of clinical radiology reports was examined to determine the coverage of the Unified Medical Language System (UMLS) in relation to the terminology used by physicians in the Radiology Department of Columbia Presbyterian Medical Center (CPMC). The UMLS semantic network contained 17 semantic types which were compatible with the types of clinical information in the reports. The type of semantic categories missing from the UMLS consisted mainly of modifier information relating to certainty, degree, and change type of information. This type of information formed a substantial part of the domain. Although most of the informational categories were found in the UMLS semantic network, most of the domain terms were not. Our results strongly suggest that the UMLS could be a significant tool for developing clinical text processing applications if it were extended to cover clinical domains.