This class contains an electronic representation of an optical counterpart or appearance of an object along with metadata to help identify, locate, and classify the image. This class is to be used for both clinical images which may be managed using a PACS and for scanned documents and other informal images. "A single SOP Instance within the series, e.g. an image, or presentation state." - HL7 FHIR, ImagingStudy.series.instance