ACR-NEMA ACR and NEMA form a joint committee Publication of Version Compression and Mag Tape Standards Publication of Version Began work on Network Version with HIS/RIS First meeting organized by ACR and NEMA in 1983

DICOM The name was changed to separate the standard from the originating body Release of Parts 1 and 8 of DICOM RSNA demonstration, Part DICOM Parts 1-9 approved, RSNA demonstration of ALL parts Part 10: Media Storage and File Format Parts 11,12, and 13 plus Supplements First successful DICOM Standard issued in 1993

Scope of DICOM To create & maintain international standards for communication of biomedical diagnostic and therapeutic information in disciplines that use digital images & associated data To achieve compatibility & to improve workflow efficiency between imaging systems & other information systems in healthcare environments worldwide. DICOM is a cooperative standard Every major diagnostic medical imaging vendor in the world has incorporated the standard into their product design Most of the professional societies throughout the world have supported & are participating in the enhancement of the standard as well DICOM is the ONLY standard in the world that covers the exchange of medical images

The DICOM Standards Committee & Working Groups WG1: Cardiac and Vascular Information WG12: Ultrasound WG2: Digital X-RayWG13: Visible Light WG3: Nuclear MedicineWG14: Security WG4: CompressionWG15: Digital Mammography WG5: Exchange MediaWG16: Magnetic Resonance WG6: Base StandardWG17: 3D WG7: RadiotherapyWG18: Clinical Trials and Education WG8: Structured ReportingWG19: Dermatologic Standards WG9: OphthalmologyWG20: Integration of Imaging and Information Systems WG10: Strategic AdvisoryWG21: Computed Tomography WG11: Display Function StandardWG-22: Dentistry WG-23: Application Hosting

Communication Standards Protocols are defined by standards A Standard is an agreement which may be voluntary, Government mandated, or International Law Protocols may also be proprietary Who Defines Communication Standards? User Consortia (e.g., HL7) Organizations (e.g., NEMA, IEEE) US Government Agencies (e.g., ANSI, NIST) Foreign Government Agencies (e.g., CEN) United Nations (e.g., ISO, CCITT)

ISO Reference Model LLC MAC PHYSICAL DATA LINK NETWORK TRANSPORT SESSION PRESENTATION APPLICATION Fiber, Coax, UTP, µWave End-to-End communication Data Formatting, Compression,Encryption File Transfer, , HTTP Ethernet, FDDI, etc. Internetworking Upper Layers (DICOM) Synchronization,Comm. Management Lower Layers

The Parts of the DICOM Standard Part 1 - Introduction and Overview Part 2 - Conformance Part 3 - Information Object Definitions Part 4 - Service Class Definitions Part 5 - Data Structures & Semantics Part 6 - Data Element Listing and Typing Part 7 - Message Exchange Protocol Part 8 - Network Support for Message Exchange More than 100 supplements (extensions) to the Standard provide additional capabilities Part 10: Media Storage and File Format for Media Interchange Part 11: Media Storage Application Profiles Part 12: Media Formats and Physical Media for Media Interchange Part 14: Grayscale Standard Display Function Part 15: Security and System Management Profiles Part 16: Content Mapping Resource Part 17: Explanatory Information Part 18: Web Access to DICOM Persistent Objects (WADO)

Technology Overview At the application layer, the services and information objects address five primary areas of functionality: Transmission and persistence of complete objects (such as images, waveforms and documents) Query and retrieval of such objects Performance of specific actions (such as printing images on film) Workflow management (support of worklists and status information) Quality and consistency of image appearance (both for display and print)

DICOM Fundamentals OBJECT DATA MODEL –DICOM is based on a completely specified data model –DICOM includes a robust UID mechanism DATA DICTIONARY –DICOM includes a large number of new data elements SERVICE CLASSES –DICOM defines classes of service for specific applications (e.g. image management, printing) and conformance levels

DICOM Terminology DICOM Message Service Element (DIMSE) - The set of DICOM Application Layer communication services. DIMSE Service Group (DSG) - A subset of the full DIMSE services which is applicable to a specific IOD. Information Object Definition (IOD) - A data abstraction of a class of real-world objects. A collection of related attributes (data elements).

DICOM Terminology Service Class - A set of functionality relating to a single type or real-world activity. Composed of a set of SOP Classes plus rules and associated semantics. Service-Object-Pair Class (SOP) - The atomic unit of DICOM functionality. Composed of an IOD and a DIMSE Service Group plus restrictions or extensions of the IOD. (Equivalent to an Object Class)

DICOM Service Classes Composite –Verification –Storage –Query/Retrieve –Study Content Notification Normalized –Patient Management –Study Management –Results Management –Basic Print Management

DICOM Data Types Value Representation Description AEApplication Entity ASAge String ATAttribute Tag CSCode String DADate DSDecimal String DTDate/Time FL Floating Point Single (4 bytes) FD Floating Point Double (8 bytes) ISInteger String LOLong String LTLong Text OBOther Byte Value Representation Description OFOther Float OWOther Word PNPerson Name SHShort String SLSigned Long SQSequence of Items SSSigned Short STShort Text TMTime UIUnique Identifier ULUnsigned Long UNUnknown USUnsigned Short UTUnlimited Text

DICOM Attribute Encoding