DICOM Structured reports are DICOM SOP Instances, organised just the same way as images etc., but which hold reports rather than images. They are typically therefore only a few kilobytes in size. They contain all the same indexing information as images, and therefore fit into the standard 4 level DICOM_Hierarchy, complete with their own "psuedo-modality" of SR. They live with the same study (and therefore have the same Study UID) as the images to which they relate, but as the DICOM rules only allow one modality per series, they (like Presentation_States) sit in their own series.
The "Structure" of Structure Report
The following graph shows the basic structure of SR files:
Use in DicomObjects
DicomObjects has full facilities for producing SR objects, including all the necessary nested Sequences, and can of course handle and store them just like other DICOM objects. Likewise, developers have full programmatic access to the data in the SR object, but DicomObjects does not however contain an internal "renderer" to display the images onto a DicomViewer.