The standard format for medical imaging storage and transmission is DICOM. openEHR is an open standard
specification in health informatics that describes the management and storage, retrieval and exchange of health data in
electronic health records. Considering that the integration of DICOM and openEHR is beneficial to information sharing,
on the basis of XML-based DICOM format, we developed a method of creating a DICOM Imaging Archetype in
openEHR to enable the integration of DICOM and openEHR.
Each DICOM file contains abundant imaging information. However, because reading a DICOM involves looking up the
DICOM Data Dictionary, the readability of a DICOM file has been limited. openEHR has innovatively adopted two level
modeling method, making clinical information divided into lower level, the information model, and upper level,
archetypes and templates. But one critical challenge posed to the development of openEHR is the information sharing
problem, especially in imaging information sharing. For example, some important imaging information cannot be
displayed in an openEHR file. In this paper, to enhance the readability of a DICOM file and semantic interoperability of
an openEHR file, we developed a method of mapping a DICOM file to an openEHR file by adopting the form of
archetype defined in openEHR. Because an archetype has a tree structure, after mapping a DICOM file to an openEHR file, the converted information is structuralized in conformance with openEHR format. This method enables the
integration of DICOM and openEHR and data exchange without losing imaging information between two standards.
Digital Imaging and Communications in Medicine (DICOM) is a standard for handling, storing, printing, and
transmitting information in medical imaging. XML (Extensible Markup Language) is a set of rules for encoding
documents in machine-readable form which has become more and more popular. The combination of these two is very
necessary and promising. Using XML tags instead of numeric labels in DICOM files will effectively increase the
readability and enhance the clear hierarchical structure of DICOM files. However, due to the fact that the XML tags rely
heavily on the orders of the tags, the strong data dependency has a lot of influence on the flexibility of inserting and
In order to improve the extensibility and sharing of DICOM files, this paper introduces XML Path-Tag to DICOM.
When a DICOM file is converted to XML format, adding simple Path-Tag into the DICOM file in place of complex tags
will keep the flexibility of a DICOM file while inserting data elements and give full play to the advantages of the
structure and readability of an XML file. Our method can solve the weak readability problem of DICOM files and the
tedious work of inserting data into an XML file. In addition, we set up a conversion engine that can transform among
traditional DICOM files, XML-DCM and XML-DCM files involving XML Path-Tag efficiently.
In order to enhance the readability, extensibility and sharing of DICOM files, we have introduced XML into DICOM file
system (SPIE Volume 5748) and the multilayer tree structure into DICOM (SPIE Volume 6145). In this paper, we
proposed mapping DICOM to ODF(OpenDocument Format), for it is also based on XML. As a result, the new format
realizes the separation of content(including text content and image) and display style. Meanwhile, since OpenDocument
files take the format of a ZIP compressed archive, the new kind of DICOM files can benefit from ZIP's lossless
compression to reduce file size. Moreover, this open format can also guarantee long-term access to data without legal or
technical barriers, making medical images accessible to various fields.
In order to enhance the sharing of DICOM, we have proposed to introduce XML into the DICOM Data
Dictionary and file system (SPIE2005 5748-57)1, which can extend the readability and the expansibility of
DICOM files. In our research, we will improve the data structure of DICOM on the basis of the idea we proposed.
We change the one-dimension array into the multilayer tree structure. We also change the original DICOM
Dictionary, which consists of numerical code, into the structured Data Dictionary according to the technique of
XML. All of the elements are in the special modules. The idea of modulization promotes the searching efficiency
and reduces the data redundancy. Data conversion replaces DICOM numerical code with character string tags
containing explicit meaning. These information modules are also formed as a multilayer tree structure according to
their modules, and they are kept as this structure in storage, transmission and display. After being added and
translated, the private data (such as a Diagnostic Report) will be linked directly as a new child-node to the
root-node so that the information is available without any special Data Dictionary. In this way, we can extend the
capacity of data elements, integrate data from different sources, and enlarge the scope of data sharing in DICOM.
Proc. SPIE. 5748, Medical Imaging 2005: PACS and Imaging Informatics
KEYWORDS: Information fusion, Medicine, Data storage, Image processing, Medical imaging, Associative arrays, Data conversion, Data communications, Standards development, Picture Archiving and Communication System
As a standard of communication and storage for medical digital images, DICOM has been playing a very important role in integration of hospital information. In DICOM, tags are expressed by numbers, and only standard data elements can be shared by looking up Data Dictionary while private tags can not. As such, a DICOM file's readability and extensibility is limited. In addition, reading DICOM files needs special software. In our research, we introduced XML into DICOM, defining an XML-based DICOM special transfer format, XML-DCM, a DICOM storage format, X-DCM, as well as developing a program package to realize format interchange among DICOM, XML-DCM, and X-DCM. XML-DCM is based on the DICOM structure while replacing numeric tags with accessible XML character string tags. The merits are as following: a) every character string tag of XML-DCM has explicit meaning, so users can understand standard data elements and those private data elements easily without looking up the Data Dictionary. In this way, the readability and data sharing of DICOM files are greatly improved; b) According to requirements, users can set new character string tags with explicit meaning to their own system to extend the capacity of data elements; c) User can read the medical image and associated information conveniently through IE, ultimately enlarging the scope of data sharing. The application of storage format X-DCM will reduce data redundancy and save storage memory. The result of practical application shows that XML-DCM does favor integration and share of medical image data among different systems or devices.