254668610-Dicom-ppt PACS architecture.ppt
- 2. Communication Protocols: Key to Connectivity Layered Model, each layer performs a specific function Set of Services and Protocols Connectivity requires sharing of a complete protocol Communication requires a shared Semantic Context
- 3. 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, E-mail, HTTP Ethernet, FDDI, etc. Internetworking Upper Layers (DICOM) Synchronization,Comm. Management Lower Layers
- 4. 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
- 5. 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)
- 6. ACR-NEMA 1982 - ACR and NEMA form a joint committee 1985 - Publication of Version 1.0 1988 - Compression and Mag Tape Standards 1988 - Publication of Version 2.0 1989 - Began work on Network Version with HIS/RIS
- 7. DICOM The name was changed to separate the standard from the originating body 1991 - Release of Parts 1 and 8 of DICOM 1992 - RSNA demonstration, Part 8 1993 - DICOM Parts 1-9 approved, RSNA demonstration of ALL parts 1994 - Part 10: Media Storage and File Format 1995 - Parts 11,12, and 13 plus Supplements
- 8. 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 Part 9 - Point-to-Point Support
- 9. The Parts of the DICOM Standard Part 10 - Media Storage and File Format Part 11 - Media Storage Application Profiles Part 12 - Media Formats and Physical Media Part 13 - Print Management Point-to-Point
- 10. DICOM Application Domain MAGN ETOM Information Management System Storage, Query/Retrieve Storage, Query/Retrieve , , Study Component Study Component Query/Retrieve, Patient & Study Management Query/Retrieve, Patient & Study Management Query/Retrieve Query/Retrieve Results Management Results Management Print Management Print Management Media Exchange Media Exchange LiteBox
- 11. Summary of DICOM Features NETWORK PROTOCOL DICOM incorporates negotiation to permit nodes to agree on the functions to be performed MESSAGE ENCODING DICOM defines 24 data types (V2.0 had 4) DICOM message encoding includes JPEG compression (17 varients) DICOM includes encapsulated image and multi-frame syntaxes DICOM supports multiple character repertoires
- 12. Summary of DICOM Features 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
- 13. Summary of DICOM Features Off-Line Media Support DICOM defines a directory structure and media profiles CONFORMANCE DICOM requires conformance statements and contains detailed conformance requirements
- 14. 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).
- 15. 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)
- 16. Service-Object Pair Class SOP SOP Data Dictionary Data Dictionary Real-World Object Real-World Object Information Object Information Object DIMSE Service Group DIMSE Service Group
- 17. DICOM Service Classes Composite Verification Storage Query/Retrieve Study Content Notification Normalized Patient Management Study Management Results Management Basic Print Management
- 18. Conformance DICOM Part 2 specifies the structure of a conformance statement DICOM does not specify a test suite or a compliance verification mechanism All DICOM implementations must be supported by a properly constructed conformance statement
- 19. DICOM Conformance Statement Implementation Model which describes the Application Entities in the implementation Detailed specification of each Application Entity SOP Classes supported policies for initiation and acceptance of associations Presentation Contexts SOP options Supported communications protocols Specializations Configuration
- 20. Purpose of a Conformance Statement Allow a user to determine which optional components of the DICOM Standard are supported by a particular implementation, and what extensions or specializations an implementation adds. By comparing the Conformance Statements from two implementations, a knowledgeable user should be able to determine whether or not interoperability is possible.
- 21. DICOM Conformance Testing No Formal Mechanism is Defined in the Standard Committee for the Advancement of DICOM Define initial test plan and cross-connect matrix Future RFP for organization to monitor the process Problem: How to Map DICOM Conformance Statements into Test Plans
- 22. The DICOM Explosion Joint CEN-DICOM development Medicom = DICOM MIPS 95 work is underway with JIRA IS&C Harmonization is also in progress HL7 Harmonization continuing interest New DICOM organization Companies: NEMA and non-NEMA ACR, ACC, CAP, ... individuals
- 23. Summar y Networking is a critical component of all medical imaging systems Support for Open Communication Standards is a MUST DICOM is here, NOW DICOM products exist on the market DICOM is emerging as THE common protocol for medical image communication - WORLD WIDE!