Available in LEADTOOLS Medical Imaging toolkits.
Information Object Definitions: Maneuvering Through the IOD Table
L_DicomGetRootIOD
L_DicomGetParentIOD
L_DicomGetChildIOD
L_DicomGetFirstIOD
L_DicomGetLastIOD
L_DicomGetPrevIOD
L_DicomGetNextIOD
L_DicomGetCountModuleIOD
L_DicomExistsIOD