The OFFIS DICOM Toolkit DCMTK In 1993, the OFFIS institute and Oldenburg University, Germany supported by CERIUM, Rennes, France, developed a DICOM implementation on behalf of CEN/TC251/WG4 as part of a DICOM demonstration at RSNA'93. The software started with a early version of the DICOM Upper Layer Protocol facility developed by the Mallinckrodt Institute of Radiology in St. Louis, USA. The rest of this software was developed independently and successfully demonstrated for the first time at RSNA'93. Interoperability was demonstrated with around 20 implementations from vendors of medical imaging equipment, with both this software and the Mallinckrodt Institute of Radiology's own implementation. This implementation became known as the European CTN (Central Test Node). The European CTN software was further extended by OFFIS in 1994 and 1995 and used as part of DICOM demonstrations at EuroPACS'94 in Geneva, ECR'95 in Vienna and CAR'95 in Berlin where even more vendors of imaging equipment were able to demonstrate interoperability. During 1996, the software was rewritten by OFFIS to use a new C++ based DICOM encoding/decoding library and has been supplemented with a Modality Worklist CTN, demonstrated for the first time at CAR'96 in Paris, France. The CAR'96 DICOM demonstration featured Modality Worklist Management and Image Storage/Query/Retrieval. The available software includes source code and documentation for the worklist management and image storage/query/retrieve server applications, a number of test applications, and the necessary libraries. A similar industry demonstration also took place at the European Congress of Radiology (ECR '97) in Vienna and at CAR'97 in Berlin. Beginning with release 3.0 (1996), the software package was renamed to DCMTK (DiCoM ToolKit). It contains a number of improvements over the "European CTN" software previously available from OFFIS/Oldenburg University, the most important being: - configuration using GNU autoconf - a modality worklist SCP and SCU - a new C++ encoding/decoding library - support for offline media - support for explicit VR transfer syntaxes - a user-extensible data dictionary - support for all balloted image SOP classes In 1997, a tool allowing to create DICOMDIRs according to the "General Purpose CD-R Image Interchange Profile" was added. This tool was used to master the CAR' 97 and NEMA '97 DICOM Demonstration CDs. Beginning in 1998, new libraries for efficient rendering of DICOM grayscale images, display calibration according to DICOM part 14 and an implementation of the Grayscale Softcopy Presentation State (GSPS) supplement were added and demonstrated at ECR '99 and RSNA InfoRAD '99. Together with an implementation of DICOM basic grayscale print management (SCU and SCP, both supporting presentation LUT) and a small GSPS checker these tools were used for testing purposes for the "softcopy and hardcopy consistency" part of the IHE (Integrating the Healthcare Enterprise), an initiative of RSNA and HIMSS. For the RSNA 2000 and the ECR 2001, DICOM's new security extensions on secure transport connections (TLS - Transport Layer Security) and Digital Signatures were added together with a library for DICOM Structured Reporting. Furthermore, support for color images has been moved to the public part of the toolkit (required separate licensing before). To be continued ... In addition to the freely available DCMTK software, OFFIS has also developed other DICOM software which must be licensed separately. These separate packages build on the facilities provided by DCMTK. -- See: http://dicom.offis.de/