URL ONTOLOGY	Radiology Lexicon	Source
https://bioportal.bioontology.org/ontologies/URL/#Port	http://www.radlex.org/RID/RID50336	LOOM
https://bioportal.bioontology.org/ontologies/URL/#Body	http://www.radlex.org/RID/RID5950	LOOM
https://bioportal.bioontology.org/ontologies/URL/#HEAD	http://www.radlex.org/RID/RID9080	LOOM