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CE/IT Integration

DICOM Key Concepts Technical ReviewInterconnectivity, interoperability and basic troubleshooting

Jeff KabachinskiDirector, Technical DevelopmentAramark Healthcare Technologies Kabachinski-jeffery@aramark.com

Thursday, July 23rd, 2015

9AM to 11AM

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CE/IT Integration

What is Interoperability? HIMSS defines Interoperability as …

Interoperability means the ability of health information systems to work together within and across organizational boundaries in order to advance the effective delivery of healthcare for individuals and communities.

Today’s Agenda

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HIS & its Constituent Networks• PACS, RIS, LIS, PharmIT, ADT, MDDS, Medical IT• A peek into PACS

The OSI Reference Model• Network Communication defined – how network traffic

is configured• Overview: Ethernet, TCP/IP & DICOM upper layers

DICOM Standard Configuration• DICOM statement review• Service classes to act on the data• DICOM Essentials – IODs, VRs, UIDs & Conformance

Statements

The JIT Genius• One way to stay current

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HIS

HISADT, CPOE,HIS Master Patient Index

RISPACS

Rx-IT

LIS

Medical DeviceNetwork

MDISEHR RMON

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Picture Archival andCommunication Systems

Networked computers, servers, and archives to store digital images

Accepts any image in DICOM format. (Digital Imaging and COmmunications in Medicine)

Serves as the file room, reading room, duplicator, and courier

Provides image access to multiple users at the same time, on-demand images, electronic annotations of images, and specialty image processing

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DICOM Intro

The DICOM Standard specifies a non-proprietary data interchange protocol, digital image format, and file structure for biomedical images and image-related information.

DICOM addresses five general application areas (1) Network image management(2) Network image interpretation management(3) Network print management(4) Imaging procedure management(5) Off-line storage media management

The main objective is to facilitate communication and interoperability.DICOM addresses all of the technical aspects necessary to allow complying OEMs to talk to and understand one another.

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Layer Name Keywords

7 Application Semantics

6 Presentation Syntax

5 Session Dialog Coordination

4 Transport Reliable Data Transfer

3 Network Routing and Relaying

2 Data Link Technology-Specific Transfer

1 Physical Physical Connections

Layer Name Keywords

7 Application Semantics

6 Presentation Syntax

5 Session Dialog Coordination

4 Transport Reliable Data Transfer

3 Network Routing and Relaying

2 Data Link

1 Physical Physical Connections

The Layers

OSI Reference Model

Physical

Data Link

Network

Transport

Session

Presentation

Application

Logical Link Control

Media Access Control

Logical Link Control

Media Access Control

Medium for transfer of signal

Method for getting data on & off the media

Identifying your location on the Network

Transfer of data

Defining the data format

Defining the connection

Defining the app socket

OSI Reference Model

OSI Reference Model

AH Data

PH Data

SH Data

TH Data

NH Data

DH Data

Bit Stream

Application

Presentation

Session

Transport

Network

Data Link

Physical

AH Data

SH Data

TH Data

NH Data

DH DataMedia Access

Identifying your location on the Network

Transfer of data

Defining the data format

Defining the connection

Defining the app socket

PH Data

Bit StreamMedia

OSI Reference Model

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Ethernet

Data Packet Architecture

Timing Frame Destination Source Amount of data enclosed Checksum

7 Bytes 1 6 bytes 6 bytes 2 bytes 46 to 1522 bytes 4 bytes

10101010101....alternating 1s & 0s

SFD: 10101011

00:00:A1:FD:23:C900:00:A1:1E:04:12

Preamble Addressing Length Data CRC

Shortest Packet Slot Time

6 Bytes of the Ethernet destination address

6 Bytes of the Ethernet source address

2 Data length field

46 Length of smallest data payload

+ 4 For the CRC field

64 Total # bytes in the shortest packet

X 8 Bits in a byte

512 Total # of bits

X 0.1μS Bit width @ 10Mbs

51.2μS Slot time

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TCP/IP Protocol

IP Data Packet Architecture

Ethernet packet

IP packet

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TCP/IP Protocol

Data Packet Architecture

Ethernet packet

IP packet

TCP packet

TCP/IP Protocol

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0-1023Are “well known ports” assigned by the IANA (Internet Assigned Numbers Authority). Some examples: http uses port 80, FTP data - 20 FTP control -21, SMTP – 25, POP3 – 110, DICOM – 104, 1044, 4006

1024 – 49151Are requested from the IANA to become “registered ports”. For example: Googletalk has registered ports numbered 19294, 19295, 19302

49152 – 65535Unassigned open space or Free Space – an area open to use and often where cybercriminals play…

TCP Port Number Ranges 

TCP port number or addresses are 2 bytes written as one number in decimal notation – from 0 to 65535.

TCP Port Number Ranges 

Go to www.iana.org to get the current complete list of assigned and registered TCP port numbers.

TCP/IP Protocol

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0-1023Are “well known ports” assigned by the IANA (Internet Assigned Numbers Authority). Some examples: http uses port 80, FTP data - 20 FTP control -21, SMTP – 25, POP3 – 110, DICOM – 104, 1044, 4006

1024 – 49151Are requested from the IANA to become “registered ports”. For example: Googletalk has registered ports numbered 19294, 19295, 19302

49152 – 65535Unassigned open space or Free Space – an area open to use and often where cybercriminals play…

TCP Port Number Ranges 

TCP port number or addresses are 2 bytes written as one number in decimal notation – from 0 to 65535.

TCP Port Number Ranges 

Go to www.iana.org to get the current complete list of assigned and registered TCP port numbers.

URL – Uniform Resource Locator• Example: http://www.google.com:80

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Data Packet Architecture

Ethernet packet

IP packet

UDP packet

TCP/IP Protocol

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Physical

Data Link

Network

Transport

Session

Presentation

Application

Logical Link Control

Media Access Control

Logical Link Control

Media Access Control

Medium to transfer signal

Method for getting data on & off the media

Identifying your location on the Network

Transfer of data

Defining the data format

Defining the connection

Defining the app socket

OSI Model

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Physical

Data Link

Network

Transport

Session

Presentation

Application

Medium to transfer signal

Method for getting data on & off the media

Identifying your location on the Network

Transfer of data

Defining the data format

Defining the connection

Defining the app socket

Wires

Ethernet

IP

TCP/UDP

NOS

OSI Model

OSI Model

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DICOM & the OSI Model

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DICOM Intro

The DICOM Standard specifies a non-proprietary data interchange protocol, digital image format, and file structure for biomedical images and image-related information.

DICOM addresses five general application areas (1) Network image management(2) Network image interpretation management(3) Network print management(4) Imaging procedure management(5) Off-line storage media management

DICOM consists of the following parts:

PS 3.1: Introduction and Overview (this document)

PS 3.2: Conformance

PS 3.3: Information Object Definitions

PS 3.4: Service Class Specifications

PS 3.5: Data Structure and Encoding

PS 3.6: Data Dictionary

PS 3.7: Message Exchange

PS 3.8: Network Communication Support for Message Exchange

PS 3.9: Retired

PS 3.10: Media Storage and File Format for Data Interchange

PS 3.11: Media Storage Application Profiles

PS 3.12: Media Formats and Physical Media for Data Interchange

PS 3.13: Retired

PS 3.14: Grayscale Standard Display Function

PS 3.15: Security Profiles

PS 3.16: Content Mapping Resource

PS 3.17: Explanatory Information

PS 3.18: Web Access to DICOM Persistent Objects (WADO)

PS 3.19: Application Hosting

PS 3.20: Transformation of DICOM to and from HL7 Standards

DICOM consists of the following parts:

PS 3.1: Introduction and Overview (this document)

PS 3.2: Conformance

PS 3.3: Information Object Definitions

PS 3.4: Service Class Specifications

PS 3.5: Data Structure and Encoding

PS 3.6: Data Dictionary

PS 3.7: Message Exchange

PS 3.8: Network Communication Support for Message Exchange

PS 3.9: Retired

PS 3.10: Media Storage and File Format for Data Interchange

PS 3.11: Media Storage Application Profiles

PS 3.12: Media Formats and Physical Media for Data Interchange

PS 3.13: Retired

PS 3.14: Grayscale Standard Display Function

PS 3.15: Security Profiles

PS 3.16: Content Mapping Resource

PS 3.17: Explanatory Information

PS 3.18: Web Access to DICOM Persistent Objects (WADO)

PS 3.19: Application Hosting

PS 3.20: Transformation of DICOM to and from HL7 Standards

The DICOM Standard has 18 parts• Each part is a separate document• All the grim details are here

• PS3.3 has 1314 pages for example

• Parts can be at different Rev levels• Most have been updated in 2014

• Freely available at medical.nema.org

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DICOM Terminology

“I am sending a CT image to you”

Service Class Information Object Definition

Provider or SCP User or SCU

SOP

Service Class Provider Service Class User

Service Object Pair

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DICOM Terminology

“I am sending a CT image to you”

Service Class Information Object Definition

Provider or SCP User or SCU

SOP

Service Class Provider Service Class User

Service Object Pair

All IOD details can be found in DICOM PS3.3 2014b

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DICOM IOD’s• Information object definitions (IODs) are simply a way to

classify & encode data being transmitted via DICOM. • Typically, the target information is digitized image

information and any image related data (e.g., waveforms, formatted reports, radiation therapy dosage).

• Each IOD contains the description of its purpose and a list of the attributes that define it.

• The service class itself does not contain the values of the attributes, just which attributes will be included.

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DICOM IOD’sOther sections of the standard that affect the IOD are:

• PS3.5: Data Structure and Semantics. This section addresses which image compression technique is used, as well the encoding rules necessary to construct the data stream (which in turn is made up of data elements).

• PS3.6: Data Dictionary. This is the centralized registry of DICOM Data Elements. Each element is defined with things like a unique tag that includes a group and element number, an element name, a value representation (alphanumeric), and the number of values per attribute.

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DICOM IOD’sThink of the Data Dictionary as a lookup table for data types. The Data Dictionary is connected to the Value Representation (VR) and the encoding of the data elements.

It’s important to be clued in to the format of VR and data elements so that you can recognize them in a DICOM message.

PS3.14: Grayscale Standard Display Function. This section of the standard provides methods of calibrating a display system (monitor and printer) so that it presents grayscale images consistently. PS3.14 uses Barten’s model of the human visual system, another example of the important detail covered in the standard.

PS3.16: Content Mapping Resource. This part covers the templates and coded terms for DICOM information objects. This part also contains the glossary of terms and any country specific translations of coded terms.

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“I am storing an MR image with storage location A”

Service Class Information Object Definition

SCP SCU

SOP

Service Class Provider Service Class User

Service Object Pair

DICOM Terminology

SOP = “Store this MR image”

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DICOM Value Representations

All Elements in the DICOM Data Dictionary are organized into groups and are labeled as (Group, Element) pairs.Groups are organized into 27 Value Representation categories.

Examples:PN (0010, 0010) for patient name under the PN category.(0010, 0020) for patient ID

VR formatting in a DICOM file would look like:(0010, 0010)Smith^Jim_(001, 0030)19650926(0010, 0040)M

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The 27 DICOM Value Representations

ValueRepresentation

Description

AE Application EntityAS Age StringAT Attribute TagCS Code StringDA DateDS Decimal StringDT Date/TimeFL Floating Point Single (4 bytes)FD Floating Point Double (8 bytes)IS Integer StringLO Long StringLT Long TextOB Other ByteOF Other FloatOW Other WordPN Person NameSH Short StringSL Signed LongSQ Sequence of ItemsSS Signed ShortST Short TextTM TimeUI Unique IdentifierUL Unsigned LongUN UnknownUS Unsigned ShortUT Unlimited Text

Uses Little Endian encoding as default

For example – A1• Little endian equals 161 in

decimal• Big endian equals 26

Need to ensure that the SCU and SCP agree!

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DICOM Functions

Conformance Statements• The OEM’s DICOM Implementation

Model• SOP classes, Roles and Transfer

Syntaxes used• Communication Stack & Cybersecurity

Measures used

UID – Unique IDentifiersAn International Standard that has a Unique ID for almost every entity in DICOM – from SOP Classes and studies to pieces of equipment and individual images

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The UID is formed using the DICOM registered ROOT and an organization defined specific SUFFIX.

Field Value Field Description1. Indicates ISO (2=ITU)2. Indicates ANSI Member body (USA)840. Country Code123456 Specific Organization Code

3. Manufacturer or User defined device code152. Manufacturer or User defined s/n235. Study Number2. Series Numbner12. Image Number187636473 User Defined Numbering System

Root

Suffix

An SOP instance UID might look like:1.2.840.123456.3.152.235.2.12.187636473

ROOT: 1.2.840.123456 SUFFIX: 3.152.235.2.12.187636473

The DICOM UID

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The UID is formed using the DICOM registered ROOT and an organization defined specific SUFFIX.

Field Value Field Description1. Indicates ISO (2=ITU)2. Indicates ANSI Member body (USA)840. Country Code123456 Specific Organization Code

3. Manufacturer or User defined device code152. Manufacturer or User defined s/n235. Study Number2. Series Numbner12. Image Number187636473 User Defined Numbering System

Root

Suffix

An SOP instance UID might look like:1.2.840.123456.3.152.235.2.12.187636473

ROOT: 1.2.840.123456 SUFFIX: 3.152.235.2.12.187636473

• To determine if any two SOP classes are the same – compare their UID’s

• SUFFIX: Can use whatever numbering scheme you choose but must be unique and less than 64 characters (total) including stops

The DICOM UID

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The UID for DICOM transaction information is formed using a DICOM reserved ROOT: 1.2.840.10008

Therefore – if you open an unknown file in WordPad – for example – search for the text string 1.2.840.10008. If found you can be pretty certain that you’re dealing with a DICOM file.

Field Value Field Description1. Indicates ISO (2=ITU)2. Indicates ANSI Member body (USA)840. Country Code10008. Reserved for universal transaction UIDs

Root

The DICOM UID

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Knowledge Bits like these can help with your pattern recognition and build a foundation of DICOM network savvy

The JIT Genius Plan1. Work on the foundation2. Build a reference library

A strategy to keep pace - The JIT Genius Plan

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Knowledge Bits like these can help with your pattern recognition and build a foundation of network savvy

The JIT Genius Plan1. Work on the foundation2. Build a reference library

A strategy to keep pace - The JIT Genius Plan

Newton’s TELECOM Dictionary – Harry Newton

Digital Imaging and Communications in Medicine: A Practical Introduction and Survival Guide - Oleg Pianykh

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The JIT Genius Plan1.

2. Build a reference library• Newton's Telecom Dictionary is a great reference for

telecom, data communications, networking, computing, and the Internet. Over 21,000 definitions it is over four times larger than any other telecom and IT dictionary, and includes wireless, broadband, intranet, e-commerce, and IT terms.

• Newton explains technical concepts in non-technical language. It’s an essential reference tool to anyone managing network and telecom systems and services.

A Strategy to Keep Pace - The JIT Genius Plan

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Knowledge Bits like these can help with your pattern recognition and build a foundation of DICOM network savvy

The JIT Genius Plan1. Work on the foundation2. Build a DICOM reference library3. Keep an eye on Healthcare IT:

• www.aami.org• www.24x7mag.com• www.himss.org• Healthcareitnews.com • HealthIT.gov

A Strategy to Keep Pace - The JIT Genius Plan

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1. Work on the foundation2. Build a DICOM reference library3. Keep an eye on Healthcare IT

websites.4. Periodically Review These Sites

for Reference and Free Tools• www.iana.org

• To see registered TCP port assignments

• dicom.nema.org• Free access to all DICOM

standard sections• Access to free DICOM tools

A Strategy to Keep Pace - The JIT Genius Plan

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Knowledge Bits like these can help with your pattern recognition and build a foundation of network savvy

The JIT Genius Plan1. Work on the foundation2. Build a reference library3. Visit Key Sites4. Visit the IANA and NEMA sites for free access to the

DICOM standard and DICOM tools.

A Strategy to Keep Pace - The JIT Genius Plan