Biomedical ontologies define entities and relations in order to represent knowledge in the biomedical domain. In this paper we concentrate on the domain of medical imaging. In previous work, we analyzed a representative sample of computed tomography reports in order to determine to which entities and relations the terms used in such reports refer (with regard to the Foundational Model of Anatomy (FMA) and the recently published Open Biomedical Ontology (OBO) Relation Ontology, respectively) in order to construct an imaging ontology for electronic reporting in radiology. In this paper we expand the role of two OBO relations in particular, as they may be applied to radiological image information: the relations located_in and adjacent_to. Defining these relations in terms of the basic topological relations of Region Connection Calculus (RCC), we show how the qualitative description of image feature locations in radiological reporting may be formalized for reasoning.