value description codesystem code iri US Ultrasound Imaging NCIT C17230 http://purl.obolibrary.org/obo/NCIT_C17230 CT Computed Tomography NCIT C17204 http://purl.obolibrary.org/obo/NCIT_C17204 DX Digital Radiography NCIT C18001 http://purl.obolibrary.org/obo/NCIT_C18001 MR Magnetic Resonance Imaging NCIT C16809 http://purl.obolibrary.org/obo/NCIT_C16809 SM Slide Microscopy NCIT C190609 http://purl.obolibrary.org/obo/NCIT_C190609