1. Digital Imaging and Communication in Medicine
HL 7
Health Level 7
DICOM
Digital Imaging and Communication in Medicine

2. Communication in a hospital
Radiologie
Administration
surgery documentation
Laboratory

3. Communication in the past
Individual interface between ever two systems
High developing costs
n * (n-1) interfaces for n systems
extensive documentation
high maintenance costs
high expenditure with exchange of equipment

4. HL7
HL7 is an international community of healthcare subject matter experts and information scientists collaborating to create standards for the exchange, management and integration of electronic healthcare information. HL7 promotes the use of such standards within and among healthcare organizations to increase the effectiveness and efficiency of healthcare delivery for the benefit of all.

5. Communication with HL7
In 1987 the USA a working group was established with the goal:
Supply of formats and protocols for data exchange in the health service
Standardization of the contents
More efficient communication
Standardized language
Reduction of the implementation expenditure
International Standard
Formate: Darstellungsvorschrift z.B. für Datum, Uhrzeit, Namen, Messwerte
Protokolle: Regelung der Übertragung, z.B.:
- Anfrage, ob der Empfänger bereit ist
- Antwort, dass der Empfänger bereit ist
- Übertragung der Daten
- Quittung von Empfänger über die erhaltenen Daten
- Mitteilung vom Sender

6. Messages Aufnahme, Verlegung, Entlassung Anfragen (queries)
(admission, discharge, transfer = ADT)
Anfragen (queries)
Untersuchungsergebnisse (result reports)
Buchhaltung / Finanzen (finance)
Patientenversorgung (patient care)
Terminplanung (scheduling)
Rezept (pharmacy prescription)

7. Events The transmission of the messages is triggered by events
Example:
A01 stationäre Aufnahme Admit
A02 Verlegung Transfer
A03 Entlassung Discharge
A08 Änderung Update

8. Example Radiologie Administration A01 A01 ACK A01 ACK Laboratory
surgery documentation
The patient is admitted into the hospital
The admission programm sends a message A01 to the involved units.
They answer with the ACK-message to signal that they have received the messsage
ACK

9. Example Patient unknown Administration query message response message
Laboratory
query message
response message
A sample is arrived in the laboratory. The patient is unknown to the laboratory computer.
The laboratory computer sends a query message to the administration computer
The administration computer sends a response message including the patient data to the laboratory

10. Composition of messages
Messages consists of segments and
begin with a
Message Segment Header MSH
Segments consists of an ordered sequence of fields
Fields can be mandatory or optional
Nachrichten sind die kleinsten übermittelbaren Einheiten

11. Datatypes of fields ST String XPN Person Name TX Text XAD Adresse FT
Formatted Text
XTN
Telefon Number NM
Numeric ID
Coded Value HL7 table DT
Date IS
Coded Value user defined TS
Timestamp CN
Composite PL
Person Location

12. Example of Codetabelle
Attributwert
Description
Bezeichnung F
Female
weiblich M
Male
männlich O
Other
andere U
Unknown
unbekannt

13. A01 ADMIT A PATIENT MSH Message Header EVN Event Type
PID Patient Identification
[PD1] Additional Demographics
[ { NK1 } ] Next of Kin /Associated Parties
PV1 Patient Visit
[ PV2 ] Patient Visit - Additional Info.
[ { DB1 } ] Disability Information
[ { OBX } ] Observation/Result
[ { AL1 } ] Allergy Information
[ { DG1 } ] Diagnosis Information
[ DRG ] Diagnosis Related Group
[ { --- PROCEDURE begin
PR1 Procedures
[{ROL}] Role
} ] --- PROCEDURE end
[ { GT1 } ] Guaranto
[ { --- INSURANCE begin
IN1 Insurance
[ IN2 ] Insurance Additional Info.
[ {IN3} ] Insurance Additional Info. - Cert.
} ] --- INSURANCE end

14. Notation of Cardinality

15. Segments Used in DUMC ADT Messages
AL1 Allergy Information
DG1 Diagnosis Information
EVN Event Type
MRG Merge Information
MSH Message Header
NK1 Next of Kin
OBX Observation
PID Patient Identification
PV1 Patient Visit
PV2 Patient Visit - Additional Information
ZAP DUMC Appointment Segment
ZID DUMC Patient Identification Extension
ZV1 DUMC Patient Visit Extension
Beispiele des Duke University Medical Center

16. Example ADT – message admission of patients
A01 - Admit a Patient
MSH|^~\&|DMCADT||RADIS1|| ||ADT^A01|DMCADT |P|2.2|||NE
EVN|A01| |||MCKEL003
PID|||H89213||BOOP^BETTY^B|| |F|JOHN WRIGHT|W|3380 HIDDEN OAK AVE^^DURHAM^NC^27704||(919) |||U|UNK|241639|
PV1||I|MIN^2411^01|3|||051001^MASSEY^E^WAYNE|||MRH||||C||||A||027|||||||||||||||||||A01||10|||
ZV1|S|I|N
DG1||||CAUDA EQUINA SYN.||W
DG1||||CAUDA EQUINA SYN.||A
PID wird in
beschrieben
DUMC HL7 ADT Specifications ist im Netz nicht mehr zu finden
DUMC HL7 ADT Specifications

17. HL7 with XML Simpler to read Simpler to validate
Bute the messages are much more longer
Example :
ADT - A01 message 500 characters
ADT - A01 as XML 2127 characters
Example

18. CDA Clinical Document Architecture Document Hierarchy
Level 1
Unconstrained CDA
Header
Body
General dianostic finding
Header
Header
Body
Level 2
Section Level
templates
Header
Body
Body
X - rax finding
ECG finding
Endoscopy finding
Level 3
Entry Level
templates
Header
Body
Header
Body
Header
Body
Header
Body
Header
Body
X - rax CT
MRT
gastro
oesophago

19. DICOM Digital Imaging and Communication in Medicine
In the year 1983 the American college of Radiology (ACR) and the National Electrical Manufactures Association (NEMA) created a committee. The goal was to develop a standard for medical pictures.
In the year 1985 the first version of this standard was presented. The file format and electrical point to point a connection between two devices were defined.
In the year 1993, DICOM 3.0 a further developed standard was presented, which made communication possible between different partners over a network.

20. Goal of DICOM Standard
The goal of the DICOM Standard is to achieve compatibility and improve workflow efficiency between imaging systems and other information systems in healthcare environments worldwide
Description of the semantics of instructions and the appropriate files.
Description of the range of the implemented standards
Support of the communication in the network
Open to new applications
Use of existing international standards if possible and preparation of own standards
Beschreibt den Umfang der implementierten Standards: Stellt eine Sprache zur Verfügung, mit der teilnehmende Systeme die bereitgestellten Dienste beschreiben können.

21. Standards Information Object Definition
Abstract definition of objects for the transmission of digital medical images and information according these images
Normalized classes contain only attributes, which belong directly to the object; e.g.: the attributes of an x-ray
Compound classes can contain also attributes, which belong indirectly to the object; e.g. the patient data and diagnoses to the x-ray
Information Object Definition: Definition einiger Klassen von Informationsobjekten, die die Objekte beschreiben, die für die Kommunikation digitaler medizinischer Bilder und den damit zusammenhängenden Informationen benötigt werden, z.B. Berichte, Strahlendosen usw. Jede Klassendefinition besteht aus der Beschreibung ihres Zwecks und der Beschreibung der Attribute, die diese Klasse definieren. Es werden zwei Arten von Klassen definiert:
normalisierte Klassen enthalten nur die Attribute, die in der realen Welt in dieser Information vorhanden sind, z.B die Beschreibung einer Studie oder CT Bild.
zusammengesetzte Klassen enthalten enthalten zusätzliche Informationen wir z.B. die Patienteninformationen, die zu einem CT Bild hinzugefügt werden.‚

22. Standards Service Class Specification
Spezification of services:
A class of services joins one or more information objects with services that can be performed with these objects.
Examples of services:
Storing of data
Searching
Working lists
Printing
Service Class Specifications: Eine Serviceklasse verbindet eine oder mehrere Informationsobjekte mit Befehlen, die auf diese Objekte einwirken. Die Spezifikationen der Serviceklassen beschreiben Anforderungen an die Befehle und wie die Befehle auf die Objekte einwirken. Sie beschreiben die Anforderungen sowohl für die Diensteanbieter als auch für die Nutzer. Beispiele:
Storage Service Class
Query/Retrieve Service Class
basic Worklist Management Service Class
Print Management Service Class

23. Standards Data Dictionary
centralized registry which defines the collection of all DICOM Data
For each element, the data dictionary specifies:
— its unique tag, which consists of a group and element number
— its name
— its value representation (character string, integer, etc)
— its value multiplicity (how many values per attribute)
PS 3.6: DATA DICTIONARY
PS 3.6 of the DICOM Standard is the centralized registry which defines the collection of all DICOM Data
Elements available to represent information, along with elements utilized for interchangeable media
encoding and a list of uniquely identified items that are assigned by DICOM.
For each element, PS 3.6 specifies:
— its unique tag, which consists of a group and element number
— its name
— its value representation (character string, integer, etc)
— its value multiplicity (how many values per attribute)
— whether it is retired
For each uniquely identified item, PS 3.6 specifies:
— its unique value, which is numeric with multiple components separated by decimal points and
limited to 64 characters
— its type, either Information Object Class, definition of encoding for data transfer, or certain well
known Information Object Instances
— in which part of the DICOM Standard it is defined

24. Standards Data Structure and Semantics
specifies how DICOM applications construct and encode the Data Set information
For example specification of image compression
addresses the encoding rules necessary to construct a Data Stream
defines the semantics of a number of generic functions
PS 3.5: DATA STRUCTURE AND SEMANTICS
PS 3.5 of the DICOM Standard specifies how DICOM applications construct and encode the Data Set
information resulting from the use of the Information Objects and Services Classes defined in PS 3.3 and
PS 3.4 of the DICOM Standard. The support of a number of standard image compression techniques
(e.g., JPEG lossless and lossy) is specified.
PS 3.5 addresses the encoding rules necessary to construct a Data Stream to be conveyed in a Message
as specified in PS 3.7 of the DICOM Standard. This Data Stream is produced from the collection of Data
Elements making up the Data Set.
PS 3.5 also defines the semantics of a number of generic functions that are common to many Information
Objects. PS 3.5 defines the encoding rules for international character sets used within DICOM.

25. Standards Message Exchange
specifies both the service and protocol used by an application in a medical imaging environment to exchange Messages

26. Standards Message Exchange
This Standard defines:
— the operations and notifications made available to Service Classes
— rules to establish and terminate associations provided by the communications support and the impact on outstanding transactions
— rules that govern the exchange of Command requests and responses
— encoding rules necessary to construct Command Streams and Messages.
PS 3.7: MESSAGE EXCHANGE
PS 3.7 of the DICOM Standard specifies both the service and protocol used by an application in a
medical imaging environment to exchange Messages over the communications support services defined
in PS 3.8. A Message is composed of a Command Stream defined in PS 3.7 followed by an optional
Data Stream as defined in PS 3.5.
PS 3.7 specifies:
— the operations and notifications (DIMSE Services) made available to Service Classes defined
in PS 3.4,
— rules to establish and terminate associations provided by the communications support
specified in PS 3.8, and the impact on outstanding transactions
— rules that govern the exchange of Command requests and responses
— encoding rules necessary to construct Command Streams and Messages.

27. Standards Network Communication Support Media Storage and File Format

28. Standards Media Storage Application Profiles
specifies application specific subsets of the DICOM Standard to which an implementation may claim conformance.
Is required for the exchange of medical images and related data between different applications
PS 3.11: MEDIA STORAGE APPLICATION PROFILES
PS 3.11 of the DICOM Standard specifies application specific subsets of the DICOM Standard to which
an implementation may claim conformance. These application specific subsets will be referred to as
Application Profiles in this section. Such a conformance statement applies to the interoperable
interchange of medical images and related information on storage media for specific clinical uses. It
follows the framework, defined in PS 3.10, for the interhcange of various types of information on storage
media.
An Application Profile annex is organized into the following major parts:
a) The name of the Application Profile, or the list of Application Profiles grouped in a related class
b) A description of the clinical context of the Application Profile
c) The definition of the media storage Service Class with the device roles for the Application
Profile and associated options
d) Informative section describing the operatinal requirements of the Application Profile
e) Specification of the Information Object Classes and associated Information Objects supported
and the encoding to be used for the data transfer
f) The selection of media formats and physical media to be used
g) Other parameters which need to be specified to ensure interoperable media interchange
h) Security parameters which select the cryptographic techniques to be used with secure media
storage Application Profiles
The structure of DICOM and the design of the Application Profile mechanism is such that extension to
additional Information Object Classes and the new exchange media is straightforward.

29. Standards Storage Functions and Media Formats for Data Interchange
facilitates the interchange of information between applications in medical environments by specifying:
A structure for describing the relationship between the media storage model and a specific physical media and media format.
Specific physical media characteristics and associated media formats.

30. Standards Conformance
defines principles that implementations claiming conformance to theStandard shall follow
specifies the general requirements which must be met by any implementation claiming conformance.
defines the structure of a Conformance Statement.
PS 3.2: CONFORMANCE
PS 3.2 of the DICOM Standard defines principles that implementations claiming conformance to the
Standard shall follow:
— Conformance requirements. PS 3.2 specifies the general requirements which must be met by
any implementation claiming conformance. It references the conformance sections of other
parts of the Standard.
— Conformance Statement. PS 3.2 defines the structure of a Conformance Statement. It
specifies the information which must be present in a Conformance Statement. It references
the Conformance Statement sections of other parts of the Standard.

31. Standards
Conformance: Anforderungen an die Konformität, die eine Installation erfüllen muß, wenn sie erklärt, sich konform zu verhalten. Definition des Befehls, mit dem die Konformität erklärt wird.

32. Examples PACS Picture Archiving and Communication System
RIS Radiologie Information System
Integration