@aostropolets, @Dymshyts, or @Christian_Reich,
Got a question this morning I wasn't 100% sure if I am answering correctly.
In ATLAS, on the vocabulary page, for example if we type balloon angioplasty, what is the difference between CPT4 hierarchy and Procedure in the column class, which one is used?
My reply was the following . . . but please correct me:
Class of "CPT4 Hierarchy" I believe are parts of the CPT vocabulary that are considered classifications (the purple color indicates this). You can use these hierarchy concepts to find sets of concepts. I believe that class of "Procedures" are just anything else that doesn't have a specific procedure classifications.