Conformance Statement for the

 NINA DICOM Archive


Peter Müller
Christian Falk
Elimpex Medizintechnik
Version 1.0.0
8 October 2002


A Introduction

The NINA DICOM Archive uses DICOM as the interface to the external world. The server accepts DICOM association requests for the purpose of storing images and for image query and retrieve. The NINA DICOM Archive will initiate DICOM association requests for the purpose of sending images to an external server. The NINA DICOM Archive does not respond to any other type of network communication.

 

A.1 Implementation Model

The NINA DICOM Archive provides for storage and query/retrieval of images. It runs on Unix systems as a background process that accepts association requests from external applications. For each association request, the NINA DICOM Archive forks a copy of itself so that the copy communicates exclusively with the requesting application.

The NINA DICOM Archive will initiate a DICOM association in response to a move request from an external application.

The NINA DICOM Arichive is started at system startup by the Unix rc command startup system.

 

A.1.1 Application Data Flow Diagram

Figure 1 shows the relationship of the NINA DICOM Archive application to external applications. As noted above, the NINA DICOM Archive does not initiate any action except in response to requests which are received via DICOM communication.

 

 


A.1.2 Functional Definition of Application Entities

The NINA DICOM Archive waits for another application to connect at the TCP/IP port number specified when the application is initiated. When another application makes a DICOM association request, the NINA DICOM Archive uses a control database and logic to verify the request:

 

1. The NINA DICOM Archive uses a control table to verify that the Called Application Title used in the associ-ation request is defined on the node (Unix host-name) upon which the NINA DICOM Archive is running.

 

2. The NINA DICOM Archive uses a control table to lookup the application defined by the Calling Application Title in the association request. The NINA DICOM Archive verifies that the node from which the call origi-nated matches the value stored in the control table.

 

A.1.3 Sequencing of Real-World Activities

The NINA DICOM Archive has no way of knowing when it has a complete study or what constitutes a complete study. If it receives an image query while also receiving storage requests, the query response may not include all of the images that are in the study.

 

A.2 AE Specifications

The NINA DICOM Archive may be invoked multiple times on a single machine and the instances may operate simultaneously. In addition, each time the NINA DICOM Archive receives an association request, it forks a copy of itself. Each invocation and each forked copy of the NINA DICOM Archive represent the same Application Entity.

 

A.2.1 AE NINA DICOM Archive – Specification

The NINA DICOM Archive provides Standard Conformance to the following DICOM 3.0 SOP Classes as an SCU:

 

TABLE 1. SOP Classes Supported by NINA DICOM Archive as an SCU

SOP Class Name

SOP Class UID

Computed Radiography Image Storage

1.2.840.10008.5.1.4.1.1

CT Image Storage

1.2.840.10008.5.1.4.1.2

Ultrasound Multi-Frame Image Storage

1.2.840.10008.5.1.4.1.3

MR Image Storage

1.2.840.10008.5.1.4.1.4

Nuclear Medicine Image Storage

1.2.840.10008.5.1.4.1.20

Ultrasound Image Storage

1.2.840.10008.5.1.4.1.6

Secondary Capture Image Storage

1.2.840.10008.5.1.4.1.7

X-Ray Angiographic Image Storage

1.2.840.10008.5.1.4.1.1.12.1

X-Ray Radiofluoroscopic Image Storage

1.2.840.10008.5.1.4.1.1.12.2

 

 


The NINA DICOM Archive provides Standard Conformance to the following DICOM 3.0 SOP Classes as an SCP:

 

 

TABLE 2. SOP Classes Supported by NINA DICOM Archive as an SCP

SOP Class Name

SOP Class UID

Verification SOP Class

1.2.840.10008.1.1

Computed Radiography Image Storage

1.2.840.10008.5.1.4.1.1

CT Image Storage

1.2.840.10008.5.1.4.1.2

Ultrasound Multi-Frame Image Storage

1.2.840.10008.5.1.4.1.3

MR Image Storage

1.2.840.10008.5.1.4.1.4

Nuclear Medicine Image Storage

1.2.840.10008.5.1.4.1.20

Ultrasound Image Storage

1.2.840.10008.5.1.4.1.6

Secondary Capture Image Storage

1.2.840.10008.5.1.4.1.7

X-Ray Angiographic Image Storage

1.2.840.10008.5.1.4.1.1.12.1

X-Ray Radiofluoroscopic Image Storage

1.2.840.10008.5.1.4.1.1.12.2

 

 

Patient Root Query/Retrieve Info Model - FIND

1.2.840.10008.5.1.4.1.2.1.1

Patient Root Query/Retrieve Info Model - MOVE

1.2.840.10008.5.1.4.1.2.1.2

Study Root Query/Retrieve Info Model - FIND

1.2.840.10008.5.1.4.1.2.2.1

Study Root Query/Retrieve Info Model - MOVE

1.2.840.10008.5.1.4.1.2.2.2

 

 

A.2.1.1 Association Establishment Policies

 

A.2.1.1.1 General

The NINA DICOM Archive will attempt to initiate associations in response to C-MOVE requests from other Application Entities. The NINA DICOM Archive will only initiate associations in reponse to valid C-MOVE requests for images that are known to the server (stored in its database).

The maximum PDU size which can be transmitted by the NINA DICOM Archive is fixed at 16KB. The default maximum PDU size which can be received by the NINA DICOM Archive is configurable with a default value of 16KB and a maximum value of 32KB.

 

A.2.1.1.2 Number of Associations

The number of simultaneous associations which will be accepted by the NINA DICOM Archive are limited only by the kernel parameters of the underlying TCP/IP implementation. The NINA DICOM Archive will spawn a new process for each association request that it receives. Therefore, the NINA DICOM Archive can have multiple simultaneous connections, and there is no inherent limitation on the total number of simultaneous associations which the NINA DICOM Archive can maintain. The NINA DICOM Archive does limit each external Entity to no more than two simultaneous associations.

 

A.2.1.1.3 Asynchronous Nature

The NINA DICOM Archive does not support asynchronous operations and will not perform asynchronous win-downegotiation.

 

A.2.1.1.4 Implementation Identifying Information

The NINA DICOM Archive will provide an implementation class UID which is 1.2.826.01.368003.2.242.1.2 .

The NINA DICOM Archive will provide an implementation version name of
Elimpex NINA 1.0


A.2.1.2 Association Initiation Policy

The NINA DICOM Archive attempts to initiate one association in response to each C-MOVE command it receives from an external node. The NINA DICOM Archive attempts a single type of association request.

 

A.2.1.2.1 Real-World Activity - Move Request from an External Node

 

A.2.1.2.1.1 Associated Real-World Activity - Move Request from an External Node

The associated Real-World activity is a C-MOVE request from an external application. If an applica-tion successfully establishes an association with the NINA DICOM Archive and makes a valid C-MOVE request that identifies one or more images known by the NINA DICOM Archive, the NINA DICOM Archive will intiate an associ-ation with the destination specified in the C-MOVE request.

 

A.2.1.2.1.2 Proposed Presentation Contexts

In response to a C-MOVE request, the NINA DICOM Archive builds a complete list of images to be moved. The list includes the SOP class of each image to be moved. The NINA DICOM Archive extracts the unique SOP classes from the image lists and proposes a set of presentation contexts that includes one presentation context for each unique SOP class identified in the image list. Thus, the association request may have a single presentation context or multiple presentation contexts. Each presentation context contains the abstract syntax that identifies one image class as found in the image list.

 

TABLE 3. Proposed Presentation Contexts for NINA DICOM Archive

Presentation Context Table

Abstract Syntax

Transfer Syntax

Role

Extended Negotiation

 

Name

UID

Name List

UID List

See note

See note

DICOM Implicit VR Little

Endian Transfer Syntax

 

1.2.840.10008.1.2

SCU

None

 

 

Note: The Abstract Syntax corresponds to the value found in the database maintained by the each server. More than one presentation context can be offered, each with a different abstract syntax.

Note: The NINA DICOM Archive only supports Implicit VR Little Endian Transfer Syntax. Some images may have been stored by the NINA DICOM Archive with private elements whose encoding scheme is unknown by the NINA DICOM Archive. These elements will be transmitted by the NINA DICOM Archive exactly as they were received (in Implicit VR Little Endian Transfer Syntax), so they should be unaltered upon transmission.

 

A.2.1.2.2 SOP Specific Conformance Statement

All C-STORE operations are in the context of a C-MOVE request from an external node.

The NINA DICOM Archive sends one C-MOVE response message for each attempted C-STORE operation. The NINA DICOM Archive takes no action in response to a failure or warning status.

The NINA DICOM Archive does not attempt any extended negotiation.

The NINA DICOM Archive does not delete any elements from the files it transfers. Therefore the set of optional elements depends entirely on the contents of the files which were originally stored on the NINA DICOM Archive.

In the event that the NINA DICOM Archive receives an unsuccessful C-STORE response, the NINA DICOM Archive will continue sending the remaining images in the requested set.

 

A.2.1.3 Association Acceptance Policy

The NINA DICOM Archive accepts associations for the purpose of storing images in its database or for the pur-pose of performing query/retrieve operations on the images that have been previously stored.

The NINA DICOM Archive will only accept association requests from applications that are defined during con-figuration.In addition, the NINA DICOM Archive will only store images sent by nodes that have been enabled by a configuration step.

 

A.2.1.3.1 Real-Word Activity - Storage

The NINA DICOM Archive accepts associations from nodes that wish to store images using the C-STORE com-mand.

 

A.2.1.3.1.1 Associated Real-World Activity

The associated Real-World activity associated with the C-STORE operation is the storage of theimage on the disk of the system upon which the NINA DICOM Archive is running. Images are stored by writing the data set of the C-STORE command directly to disk with no further header or interpretation. After the image is stored to disk, the NINA DICOM Archive updates an image database with patient, study, series and image information; this image database can be used by the NINA DICOM Archive for query/retrieve operations.

The NINA DICOM Archive will issue a failure status if it is unable to store the image on disk, if the image does not conform to the IOD of the SOP class under which it was transmitted, or if the NINA DICOM Archive is not able to successfully update its image database.

 


A.2.1.3.1.2 Presentation Context Table

Any of the Presentation Contexts shown in Table 4 are acceptable to the NINA DICOM Archive for receiving images

 

TABLE 4. Acceptable Presentation Contexts for the NINA DICOM Archive

Presentation Context Table

 

Abstract Syntax

Transfer Syntax

Role

Extended Negotiation

Name

UID

Name

UID

Computed Radiograhy

Image

 

1.2.840.10008.5.1.4.1.1

DICOM

Implicit VR

Little Endian

 

1.2.840.10008.1.2

SCP

None

 

CT Image

1.2.840.10008.5.1.4.1.2

‘’

1.2.840.10008.1.2

SCP

None

Ultrasound Multi-Frame

Image Storage

 

1.2.840.10008.5.1.4.1.3

‘’

1.2.840.10008.1.2

SCP

None

 

MR Image Storage

1.2.840.10008.5.1.4.1.4

‘’

1.2.840.10008.1.2

SCP

None

 

Nuclear Medicine

Image Storage

 

1.2.840.10008.5.1.4.1.2

0

 

‘’

1.2.840.10008.1.2

SCP

None

 

Ultrasound Image

1.2.840.10008.5.1.4.1.6

‘’

1.2.840.10008.1.2

SCP

None

Secondary Capture

Image

 

1.2.840.10008.5.1.4.1.7

‘’

1.2.840.10008.1.2

SCP

None

 

X-Ray Angiographic

Image Storage

1.2.840.10008.5.1.1.12.

1

 

1.2.840.10008.1.2

SCP

None

 

  X-Ray Radiofluoro-

scopic Image Storage

1.2.840.10008.5.1.1.12.

2

 

1.2.840.10008.1.2

SCP

None

 

 

 

A.2.1.3.1.2.1 SOP Specific Conformance for SOP Class Storage

The NINA DICOM Archive implements Level 2 (Full) conformance for the Storage SOP Class.

The following attributes are modified by converting all characters to upper case before data is stored in the image database. The image files themselves are not modified.

1. Patient Name

2. Patient ID

3. Accession Number

4. Study ID

In the event that an image is successfully stored by the NINA DICOM Archive, it may be accessed by requesting associations with the NINA DICOM Archive and performing query/retrieve operations. The NINA DICOM Archive is not designed to allow other access to stored images.

The NINA DICOM Archive stores images for an indefinite period. The system has no method for deleting images once they are stored.

The NINA DICOM Archive returns the following status values in response to a C-STORE request:

0000H Image successfully stored

A700H Refused - out of resources (unable to create local file)

A900H Error- data set does not match SOP Class

C000H Error - cannot understand

 

A.2.1.3.1.3 Presentation Context Acceptance Criterion

The NINA DICOM Archive will accept any number of storage SOP classes that are listed in Table 4 above, pro-vided that the requesting application is known to the NINA DICOM Archive and has been enabled to store images on the NINA DICOM Archive (via a configuration step). The NINA DICOM Archive defines no limit on the num-ber of presentation contexts accepted. In the event that the NINA DICOM Archive runs out of resources when trying to accept ultiple presentation contexts, the NINA DICOM Archive will reject the association request.

The NINA DICOM Archive does not check for duplicate presentation contexts and will accept duplicate presen-tation contexts.

 

A.2.1.3.1.4 Transfer Syntax Selection Policies

The NINA DICOM Archive only supports the Implicit VR Little Endian transfer syntax. Any proposed presenta-tion context which includes the Implicit VR Little Endian transfer syntax will be accepted with the Implicit VR Little Endian transfer syntax. Any proposed presentation context that does not include the Implicit VR Little Endian transfer syntax will be rejected.

 

A.2.1.3.2 Real World Activity - Query

The NINA DICOM Archive accepts associations from nodes that wish to perform query (find) and retrieve (move) operations on images that have been previously stored by the NINA DICOM Archive.

 

A.2.1.3.2.1 Associated Real World Activity - Query

The real-world activity associated with C-FIND and C-MOVE requests are the query and retrieval operations initiated by another application. An application other than the NINA DICOM Archive queries the NINA DICOM Archive for patient/study/series/image information that has been previously stored by the NINA DICOM Archive and can request that the NINA DICOM Archive send images to a third application.

 


A.2.1.3.2.2 Presentation Context Table

Table 5 shows the presentation contexts that may be accepted by the NINA DICOM Archive for query opera-tions.

 

TABLE 5. Acceptable Presentation Contexts for Query Classes

Presentation Context Table

Abstract Syntax

Transfer Syntax

Role

Extended

Negotiation

Name

UID

Name

UID

Patient Root Query/

Retrieve Information

Model - FIND

 

1.2.840.10008.5.1.4.1.2

.1.1

 

DICOM

Implicit VR

Little Endian

 

1.2.840.10008.1.2

SCP

None

 

Patient Root Query/

Retrieve Information

Model - MOVE

 

1.2.840.10008.5.1.4.1.2

.1.2

 

DICOM

Implicit VR

Little Endian

 

1.2.840.10008.1.2

SCP

None

Study Root Query/

Retrieve Information

Model - FIND

 

1.2.840.10008.5.1.4.1.2

.2.1

 

DICOM

Implicit VR

Little Endian

 

1.2.840.10008.1.2

SCP

None

Study Root Query/

Retrieve Information

Model - MOVE

 

1.2.840.10008.5.1.4.1.2

.2.2

 

DICOM

Implicit VR

Little Endian

 

1.2.840.10008.1.2

SCP

None

Patient StudyOnly

Query/Retrieve Informa-tion

Model - FIND

 

1.2.840.10008.5.1.4.1.2

.3.1

 

DICOM

Implicit VR

Little Endian

 

1.2.840.10008.1.2

SCP

None

Query/Retrieve Informa-tion

Model - MOVE

 

1.2.840.10008.5.1.4.1.2

.3.3

 

DICOM

Implicit VR

Little Endian

 

1.2.840.10008.1.2

SCP

None

 

 

A.2.1.3.2.2.1 SOP Specific Conformance for SOP Class Query/Retrieve

The NINA DICOM Archive does not support relational searches. Table 6 below indicates which keys are sup-ported by the NINA DICOM Archive for the patient root information model. The NINA DICOM Archive also supports the patient/study only information model. The keys supported for that model are the same keys found in Table 6 with a level of “Patient” or “Study”. Table 8 indicates which keys are supported by the NINA DICOM Archive for the study root information model. These tables include the optional and required keys that are supported. Optional keys are supported like required keys. The NINA DICOM Archive does not support relational queries.

 


TABLE 6. Keys Supported for Patient Root Information Mode

Level

Description

Tag

Type

Patient

Patient Name

0010 0010

R

Patient

Patient ID

0010 0020

U

Patient

Patient Birth Date

0010 0030

O

Patient

Patient Birth Time

0010 0032

O

 

 

 

 

Patient

Patient Sex

0010 0040

O

Study

Study Date

0008 0020

R

Study

Study Time

0008 0030

R

Study

Accession Number

0008 0050

R

Study

Study ID

0020 0010

R

Study

Study Instance UID

0020 000D

U

Study

Referring Physican Name

0008 0090

O

Study

Study Description

0008 1030

O

Study

Patient’s Age

0010 1010

O

Study

Patient’s Size

0010 1020

O

Study

Patient’s Weight

0010 1030

O

Series

Modality

0008 0060

R

Series

Series Number

0020 0011

R

Series

Series Instance UID

0020 000E

U

Series

Body Part Examined

0018 0015

O

 

 

 

 

Image

Image Number

0020 0013

R

Image

SOP Instance UID

0008 0018

U

Image

SOP Class UID

0008 0016

O

Image

Samples Per Pixel

0028 0002

O

Image

Rows

0028 0010

O

Image

Columns

0028 0011

O

Image

Bits Allocated

0028 0100

O

Image

Bits Stored

0028 0101

O

Image

Pixel Representation

0028 0103

O

 

 

The NINA DICOM Archive supports the three MOVE SOP classes listed in Table 5. In response to a move request, the NINA DICOM Archive supports the Storage SOP classes that are listed in Table 1.

 

 


TABLE 7. Keys Supported for Study Root Information Model

 

Level

Description

Tag

Type

Study

Study Date

0008 0020

R

Study

Study Time

0008 0030

R

Study

Accession Number

0008 0050

R

Study

Patient Name

0010 0010

R

Study

Patient ID

0010 0020

R

Study

Study ID

0020 0010

R

Study

Study Instance UID

0020 000D

U

Study

Referring Physican Name

0008 0090

O

Study

Study Description

0008 1030

O

Study

Patient Birth Date

0010 0030

O

Study

Patient Birth Time

0010 0032

O

Study

Patient Sex

0010 0040

O

Study

Patient’s Age

0010 1010

O

Study

Patient’s Size

0010 1020

O

Study

Patient’s Weight

0010 1030

O

 

 

 

 

Series

Modality

0008 0060

R

Series

Series Number

0020 0011

R

Series

Series Instance UID

0020 000E

U

Series

Body Part Examined

0018 0015

O

 

 

 

 

Image

Image Number

0020 0013

R

Image

SOP Instance UID

0008 0018

U

Image

SOP Class UID

0008 0016

O

Image

Samples Per Pixel

0028 0002

O

Image

Rows

0028 0010

O

Image

Columns

0028 0011

O

Image

Bits Allocated

0028 0100

O

Image

Bits Stored

0028 0101

O

Image

Pixel Representation

0028 0103

O

 

 

A.2.1.3.2.3 Presentation Context Acceptance Criteria

The NINA DICOM Archive will accept any number of query SOP classes that are listed in Table 5 above, pro-vided that the requesting application is known to the NINA DICOM Archive and has been enabled to make requests from the NINA DICOM Archive (via a configuration step). The NINA DICOM Archive defines no limit on the number of presentation contexts accepted. In the event that the NINA DICOM Archive runs out of resources when trying to accept multiple presentation contexts, the NINA DICOM Archive will reject the association

request.

The NINA DICOM Archive does not check for duplicate presentation contexts and will accept duplicate presen-tation contexts.

 

A.2.1.3.2.4 Transfer Syntax Selection Policies

The NINA DICOM Archive only supports the Implicit VR Little Endian transfer syntax. Any proposed presenta-tion context which includes the Implicit VR Little Endian transfer syntax will be accepted with the Implicit VR Little Endian transfer syntax. Any proposed presentation context that does not include the Implicit VR Little Endian transfer syntax will be rejected.

 


A.2.1.3.3 Real World Activity - Verification

The NINA DICOM Archive accepts associations from nodes that wish to perform a verification operation on the NINA DICOM Archive.

 

A.2.1.3.3.1 Associated Real World Activity - Verification

The real-world activity associated with the C-ECHO request is that an external node wishes to verify network or server operation without initiating any actual work.

 

A.2.1.3.3.2 Presentation Context Table

Table 8 shows the presentation contexts that may be accepted by the NINA DICOM Archive for verification operations.

 

TABLE 8. Acceptable Presentation Contexts for the NINA DICOM Archive for Verification

Presentation Context Table

Abstract Syntax

Transfer Syntax

Role

Extended

Negotiation

Name

UID

Name

UID

Verification

1.2.840.10008.1.1

DICOM

Implicit VR

Little Endian

 

1.2.840.10008.1.2

SCP

None

 

 

 

A.2.1.3.3.2.1 SOP Specific Conformance for SOP Class Verification

 

A.2.1.3.3.3 Presentation Context Acceptance Criterion

The NINA DICOM Archive will accept any number of verification SOP classes that are listed in Table 8 above, provided that the requesting application is known to the NINA DICOM Archive (via a configuration step). The NINA DICOM Archive defines no limit on the number of presentation contexts accepted. In the event that the NINA DICOM Archive runs out of resources when trying to accept multiple presentation contexts, the NINA DICOM Archive will reject the association request.

The NINA DICOM Archive does not check for duplicate presentation contexts and will accept duplicate presen-tation contexts.

 

A.2.1.3.3.4 Transfer Syntax Selection Policies

The NINA DICOM Archive only supports the Implicit VR Little Endian transfer syntax. Any proposed presenta-tion context which includes the Implicit VR Little Endian transfer syntax will be accepted with the Implicit VR Little Endian transfer syntax. Any proposed presentation context that does not include the Implicit VR Little Endian transfer syntax will be rejected.

 

 

A.3 Communication Profiles

 

A.3.1 TCP/IP Stack

The NINA DICOM Archive provides DICOM V3.0 TCP/IP Network Communication Support as defined in Part 8 of the DICOM Standard.

 

A.3.1.1 TCP/IP API

The NINA DICOM Archive uses the TCP/IP stack from the Unix system upon which it executes. It uses a sub-routine library that is based on a Berkeley socket interface.

 


A.3.1.2 Physical Media Support

The NINA DICOM Archive exists as a software application that can be compiled on various Unix platforms. As such, it places no restrictions on the physical network. The NINA DICOM Archive has been demonstrated using TCP/IP over Ethernet (Thick Wire, Thin Wire, 10 Base T), FDDI (twisted pair into a concentrator, fiber backbone) and Tin-Can-Telephone-Net.

 

 

A.4 Extensions/Specializations/Privatizations

Not applicable

 

A.5 Configuration

The NINA DICOM Archive obtains configuration information from a “Control” database which is stored in a relational database. In this implementation, the relational database is POSTGRES.

 

A.5.1 AE Title/Presentation Address Mapping

The control table “ApplicationEntity” is used to map between AE Titles and Presentation Addresses.

 

A.5.2 Security Features

The NINA DICOM Archive uses three additional control tables to control access. These tables allow the NINA DICOM Archive to determine which nodes are allowed read and or write access and where images should be stored.

 

A.5.3 Configurable Parameters

The following parameters may be configured for the NINA DICOM Archive:

Application Entity Title

TCP/IP Port Number

 

A.5.4 Support of Extended Character Sets

The NINA DICOM Archive provides no support for extended character sets.





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