We differentiate between the original and derived DICOM objects in the IDC portal and discussions of the IDC-hosted data. By Original objects we mean DICOM objects that are produced by image acquisition equipment - MR, CT, or PET images fall into this category. By Derived objects we mean those objects that were generated by means of analysis or annotation of the original objects. Those objects can contains, for example, volumetric segmentations of the structures in the original images, or quantitative measurements of the objects in the image.