MODALITY PERFORMED
PROCEDURE STEPSERVER

Version 2.0
DICOM Conformance Statement

2012/12/14

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1.Implementation model
The server runs on top of Windows system to receive performed procedure step. It runs as a process that
accepts association requests from external applications. The server creates a separated thread for eachassociation request. Therefore, each thread communicates only with the requesting application.

1.1

Data flow
Figure 1 illustrates the relation between the server and external applications. The aforementioned service
does not perform any other operations except responding to the requests received via DICOM
connection.

MPPS
SCU
Modality
Performed
Procedure

Storage DB

Step

Send reply

Server

DICOM interface
Fig 1. MPPS server implementation model

1.2

Application Entity function definition
Once the server is launched, it is awaiting for the connections from other applications via certain TCP/IP
ports. When a DICOM association is requested from another application, the server confirms the request
by using the database and the logic.
1. The server looks up the control table in order to confirm whether the name of the requested
application contained in the association request has been defined.
2. The server looks up the control table in order to find the application defined in the association
request as the name of the requesting application. It confirms whether the name of the requesting
application matches the value stored in the control table.

12.AE Specification
The server can be called multiple times from a single equipment unit and operate by using one instance.
Moreover, every time the association request is received, the server generates a copy of itself. Calling theserver and creating its copy express the same application entity.

AE Modality Performed Procedure Step Specification

2.1The server, as an SCP, provides the standard conformance with the following DICOM 3.0 SCP classes.

Table 2. The SOP classes that the server supports as an SCPSOP Class NameSOP Class UID

Confirmation SOP class

1.2.840.10008.5.1.4.1.1

Modality Performed Procedure Step

1.2.840.10008.3.1.2.3.3

2.1.1

Association Establishment Policy

2.1.1.1

Summary

On receiving a modality performed procedure step request from another application entity, the server
attempts to initiate the association.
The default maximum PDU size for communication with the server is 32 KB.

2.1.1.2Number of associations

The number of simultaneous associations the server can accept is restricted by the kernel parameters of
the basic TCP/IP implementation. Also, although the server generates a thread pool according to thesettings at startup, the number of simultaneous associations substantially depends on the mentionedparameters.

2.1.1.3

Asynchronous nature

The server does not support asynchronous operation and does not perform asynchronous window
negotiation.

2.1.1.4

Implementation Identifying Information

The server provides the implementation class UID.

2.2

Real-World Activity – Modality Performed Procedure
StepThe server accepts associations from the nodes attempting to perform request of modality performed
procedure step.

22.2.1

Presentation Context Table
Table 5 illustrates the Presentation Contexts that the server can accept in response to the query
operations.

Table 5. Acceptable Presentation Contexts for request classPresentation Contexts
Abstract syntax
Name

Transfer syntax

UID

Modality

1.2.840.10008.5.1.4.31

Name

UID

DICOM

1.2.840.10008.1.2

performed

Implicit VR

procedure

Little endian

Role

Extended
Negotiation

SCP

Nonestep
DICOM

1.2.840.10008.1.2.1

Explicit VR
Little endian
DICOM1.2.840.10008.1.2.2

Explicit VRBig endian

2.2.2

SOP Specific Conformance for SOP class modality
performed procedure step
The server supports the modules listed in Table 6 as follows.
On receiving N-CREATE service containing Study Instance UID issued by the MWM server, if the status is[In PROGRESS] and is not received, this server returns normal termination.
On receiving N-SET service containing Affected SOP Instance UID returned as a reply from N-CREATE, if
the status is [DISCONTINUED] OR [COMPLETED], this server updates the status.
The server updates the status only based on the service request from SCU.
If for whatever reason the SCU update has not been performed, it is required to update the status byusing the database management application.
On the server, Study Instance UID and SOP Instance UID are stored in the internal database. By default
storage period is 24 hours.

Table 6. SOP Common
Attribute Name

Tag

Specific Character Set

0008 0005

N-CREATE
1C

N-SET–

Table 6. Performed Procedure Step Relationship
Attribute Name

Tag

N-CREATE

N-SET

Scheduled Step Attributes Sequence

0040 0270

1–> Study Instance UID

0020 000D

1–3>Referenced Study Sequence

0008 1110

2–>> Referenced SOP Class UID0008 1150

1–>>Referenced SOP Instance UID

0008 1155

1–> Accession Number0008 0050

2–> Placer Order Number / Imaging Service0040 2016

3–0040 20173–

> Requested Procedure ID

0040 1001

2–> Requested Procedure Description

0032 1060

2–> Scheduled Procedure Step ID

0040 0009

2–> Scheduled Procedure Step Description

0040 0007

2–> Scheduled Protocol Code Sequence

0040 0008

2–>> Code Value

0008 0100

1–>> Coding Scheme Designator

0008 01021–>> Coding Scheme Version

0008 0103

3–>> Code Meaning

0008 0104

3–

Patient’s Name

0010 0010

2–

Patient ID

0010 0020

2–

Patient’s Birth Date

0010 0030

2–

Patient’s Sex

0010 0040

2–

Referenced Patient Sequence

0008,1120

2–> Referenced SOP Class UID

0008 1150

1–> Referenced SOP Instance UID

0008 1155

1–

Request> Filler Order Number/ Imaging Service
RequestTable 6. Performed Procedure Step Data
Attribute Name

Tag

N-CREATE

N-SET

Performed Procedure Step ID

0040 0253

1–

Performed Station AE Title

0040 0241

1–

Performed Station Name

0040 0242

2–

Performed Location

0040 0243

2–

Performed Procedure Step Start Date0040 0244

1–

Performed Procedure Step Start Time0040 0245

1–

Performed Procedure Step Status

0040 0252

1

1

Performed Procedure Step Description

0040 0254

22

Performed Procedure Type Description

0040 0255

22

Procedure Code Sequence

0008 1032

22> Code Value

0008 0100

11> Coding Scheme Designator

0008 0102

11>> Coding Scheme Version

0008 0103

334

> Code Meaning

0008 0104

33

Performed Procedure Step End Date0040 0250

21

Performed Procedure Step End Time0040 0251

21

Comments on the Performed Step0040 0280

33

Table 6. Image Collection Results
Attribute Name

Tag

N-CREATE

N-SETModality

0008 0060

1–Study ID

0020 0010

2–

Performed Protocol Code Sequence

0040 0260

22> Code Value

0008 0100

11> Coding Scheme Designator

0008 0102

11>> Coding Scheme Version0008 0103

33> Code Meaning

0008 0104

33

Performed Series Sequence

0040 0340

21> Performing Physician's Name

0008 1050

22> Protocol Name

0018 1030

11> Operators' Name

0008 1070

22> Series Instance UID

0020 000E11> Series Description

0008 103E

22> Retrieve AE Title

0008 0054

22> Referenced Image Sequence

0008 1140

22>> Referenced SOP Class UID

0008 1150

11>> Referenced SOP Instance UID

0008 1155

11> Referenced Unique SOP Instance Sequence 0040 0220

22>> Referenced SOP Class UID

0008 1150

11>> Referenced SOP Instance UID

0008 1155

113333> All other attributes from Performed Series
Sequence
All other attributes from radiation dosemodule, bill creation, material code module

2.2.3

Presentation Context Acceptance Criterion
Whether the server receives association requests from unknown applications depends on the systemsettings. Only if such requests are allowed, any number of the request SOP classes specified in Table 5
can be accepted. The server does not define a limit for the number of the accepted presentation
contexts. Also, among several duplicated presentation contexts, the first accepted one is to be selected.

2.2.4

Transfer Syntax Selection Policy
By default, the server selects transfer syntax according to the priority determined in Table 5; however thispriority can be changed in the system settings.

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2.3

Real-World Activity – ConfirmingThis server accepts the associations from the nodes attempting to perform confirmation on the imageserver.

2.3.1

Related Real-World Activity – Confirming
The real-world activity related to C-ECHO requests attempts to confirm the network and server
operations without initiating actual operation of external nodes.

2.3.2

Presentation Context Table
Table 8 illustrates the Presentation Contexts the server can accept in response to the confirming
operation.

Table 8. Proposed Presentation Contexts of the Server for Confirming Operation
Presentation Contexts
Abstract Syntax

Transfer Syntax

RoleNameUID

Name

UID

Confirm

1.2.840.10008.1.1

DICOM

1.2.840.10008.1.2

Extension
Negotiation

SCP

None

Implicit VR
Little endian

2.3.3

Presentation Context Acceptance Criterion
Whether the server receives association requests from unknown applications depends on the systemsettings. Only if such requests are allowed, any number of the request SOP classes specified in Table 5
can be accepted. The server does not define a limit for the number of the accepted presentation
contexts. Also, among several duplicated presentation contexts, the first accepted one is to be selected.

2.3.4Transfer Syntax Selection Criterion
By default, the server selects transfer syntax according to the priority determined in Table 5; however thispriority can be changed in the system settings.

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3.Communication Profile
3.1

TCP/IP Stack
The server provides support for the DICOM V3.0 TCP/IP network communication defined in the part 8 of
the DICOM standard.

3.1.1

TCP/IP API
The server is using the TCP/IP stack from Windows system that is running the image server. The
subroutine library based on Berkeley sockets interface has been used.

3.1.2

Physical media support
The server exists as a software that can be compiled on various Windows platforms. Therefore, there isno limitation of the physical network. The image server is implemented by using TCP/IP over Ethernet(Thick Wire, Thin Wire, 10 Base T), FDDI (twisted pair into a concentrator, fiber backbone), Tin-CanTelephone-Net.

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4.Extension / Specialization / Privatization
Not applicable8

5.Configuration
The server obtains the configuration information from the “control” database stored in the relateddatabase. In this implementation, the related database is an ini file.

AE Title / Presentation Address Mapping

5.1“Application Entity” in the control table is used for mapping between AE titles and presentation address.

Configurable parameters

5.2

The following parameters can be configured on the image server.

5.3-

Application entity title-

Maximum PDU size-

Number of TCP/IP ports

Support of extended character sets
The server supports [ISO 2022 IR 13] and [ISO 2022 IR 87].

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