DICOM Digital Imaging Communications in Medicine Communication Protocols

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DICOM Digital Imaging Communications in Medicine

DICOM Digital Imaging Communications in Medicine

Communication Protocols: Key to Connectivity n Layered Model, each layer performs a specific function

Communication Protocols: Key to Connectivity n Layered Model, each layer performs a specific function n Set of Services and Protocols n Connectivity requires sharing of a complete protocol n Communication requires a shared Semantic Context

ISO Reference Model APPLICATION Upper Layers (DICOM) PRESENTATION SESSION Lower Layers File Transfer, E-mail,

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

Communication Standards n Protocols are defined by standards n A Standard is an agreement

Communication Standards n Protocols are defined by standards n A Standard is an agreement which may be voluntary, Government mandated, or International Law n Protocols may also be proprietary

Who Defines Communication Standards? n User Consortia (e. g. , HL 7) n Organizations

Who Defines Communication Standards? n User Consortia (e. g. , HL 7) n Organizations (e. g. , NEMA, IEEE) n US Government Agencies (e. g. , ANSI, NIST) n Foreign Government Agencies (e. g. , CEN) n United Nations (e. g. , ISO, CCITT)

ACR-NEMA n 1982 - ACR and NEMA form a joint committee n 1985 -

ACR-NEMA n 1982 - ACR and NEMA form a joint committee n 1985 - Publication of Version 1. 0 n 1988 - Compression and Mag Tape Standards n 1988 - Publication of Version 2. 0 n 1989 - Began work on Network Version with HIS/RIS

DICOM n The name was changed to separate the standard from the originating body

DICOM n The name was changed to separate the standard from the originating body n 1991 - Release of Parts 1 and 8 of DICOM n 1992 - RSNA demonstration, Part 8 n 1993 - DICOM Parts 1 -9 approved, RSNA demonstration of ALL parts n 1994 - Part 10: Media Storage and File Format n 1995 - Parts 11, 12, and 13 plus Supplements

The Parts of the DICOM Standard n Part 1 - Introduction and Overview n

The Parts of the DICOM Standard n Part 1 - Introduction and Overview n Part 2 - Conformance n Part 3 - Information Object Definitions n Part 4 - Service Class Definitions n Part 5 - Data Structures & Semantics n Part 6 - Data Element Listing and Typing n Part 7 - Message Exchange Protocol n Part 8 - Network Support for Message Exchange n Part 9 - Point-to-Point Support

The Parts of the DICOM Standard n Part 10 - Media Storage and File

The Parts of the DICOM Standard n Part 10 - Media Storage and File Format n Part 11 - Media Storage Application Profiles n Part 12 - Media Formats and Physical Media n Part 13 - Print Management Point-to-Point

DICOM Application Domain Storage, Query/Retrieve, Study Component Lite. Box MAGN ETOM Print Management Query/Retrieve

DICOM Application Domain Storage, Query/Retrieve, Study Component Lite. Box MAGN ETOM Print Management Query/Retrieve Results Management Media Exchange Query/Retrieve, Patient & Study Management Information Management System

Summary of DICOM Features n NETWORK PROTOCOL u. DICOM incorporates negotiation to permit nodes

Summary of DICOM Features n NETWORK PROTOCOL u. DICOM incorporates negotiation to permit nodes to agree on the functions to be performed n MESSAGE ENCODING u. DICOM defines 24 data types (V 2. 0 had 4) u. DICOM message encoding includes JPEG compression (17 varients) u. DICOM includes encapsulated image and multi-frame syntaxes u. DICOM supports multiple character repertoires

Summary of DICOM Features n OBJECT DATA MODEL u. DICOM is based on a

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

Summary of DICOM Features n Off-Line Media Support u. DICOM defines a directory structure

Summary of DICOM Features n Off-Line Media Support u. DICOM defines a directory structure and media profiles n CONFORMANCE u. DICOM requires conformance statements and contains detailed conformance requirements

DICOM Terminology n DICOM Message Service Element (DIMSE) - The set of DICOM Application

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

DICOM Terminology n Service Class - A set of functionality relating to a single

DICOM Terminology n 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. n 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)

Service-Object Pair Class Data Dictionary Information Object DIMSE Service Group SOP Real-World Object

Service-Object Pair Class Data Dictionary Information Object DIMSE Service Group SOP Real-World Object

DICOM Service Classes n Composite u. Verification u. Storage u. Query/Retrieve u. Study Content

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

Conformance n DICOM Part 2 specifies the structure of a conformance statement n DICOM

Conformance n DICOM Part 2 specifies the structure of a conformance statement n DICOM does not specify a test suite or a compliance verification mechanism n All DICOM implementations must be supported by a properly constructed conformance statement

DICOM Conformance Statement n Implementation Model which describes the Application Entities in the implementation

DICOM Conformance Statement n Implementation Model which describes the Application Entities in the implementation n Detailed specification of each Application Entity u. SOP Classes supported upolicies for initiation and acceptance of associations n Presentation Contexts n SOP options n Supported communications protocols n Specializations n Configuration

Purpose of a Conformance Statement n Allow a user to determine which optional components

Purpose of a Conformance Statement n 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. n By comparing the Conformance Statements from two implementations, a knowledgeable user should be able to determine whether or not interoperability is possible.

DICOM Conformance Testing n No Formal Mechanism is Defined in the Standard n Committee

DICOM Conformance Testing n No Formal Mechanism is Defined in the Standard n Committee for the Advancement of DICOM n Define initial test plan and cross-connect matrix n Future RFP for organization to monitor the process n Problem: How to Map DICOM Conformance Statements into Test Plans

The DICOM Explosion n Joint CEN-DICOM development n Medicom = DICOM n MIPS 95

The DICOM Explosion n Joint CEN-DICOM development n Medicom = DICOM n MIPS 95 work is underway with JIRA n IS&C Harmonization is also in progress n HL 7 Harmonization continuing interest n New DICOM organization u. Companies: NEMA and non-NEMA u. ACR, ACC, CAP, . . . uindividuals

Summary n Networking is a critical component of all medical imaging systems n Support

Summary n Networking is a critical component of all medical imaging systems n Support for Open Communication Standards is a MUST n DICOM is here, NOW n DICOM products exist on the market n DICOM is emerging as THE common protocol for medical image communication - WORLD WIDE!