 
The OFFIS DICOM Toolkit DCMTK

In 1993, Institute OFFIS & 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 demonstrations 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-Configure 
  - 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 (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).

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://www.offis.de/projekte/dicom/
