CTP Configuration for the Image Sharing Project

This article describes how the CTP application can be configured to interface to the Edge Server in the RSNA Image Sharing Project. The intended audience for this article is developers of the Edge Server. There are several articles on CTP on the RSNA MIRC wiki. All would be useful references when reading this article.

1 A Configuration File for the Image Source

The configuration of a CTP instance is specified by an XML file called config.xml located in the same directory as the program. The example configuration shown below assumes that unanonymized DICOM data objects are transmitted to CTP by an external application using the DICOM protocol.

<Configuration>

   <Server port="80" />

   <Pipeline name="Source Pipeline">

        <ImportService 
            name="DicomImportService"
            class="org.rsna.ctp.stdstages.DicomImportService"
            root="roots/DicomImportService" 
            port="104"
            calledAETTag="00097770" 
            callingAETTag="00097772"
            logConnections="no"
            suppressDuplicates="no"
            quarantine="quarantines/DicomImportService" />

         <Processor
            name="ObjectCache"
            class="org.rsna.ctp.stdstages.ObjectCache"
            id="ObjectCacheID"
            root="roots/ObjectCache" />

        <Anonymizer
            name="DicomAnonymizer"
            class="org.rsna.ctp.stdstages.DicomAnonymizer"
            root="roots/DicomAnonymizer" 
            lookupTable="scripts/lookup-table.properties"
            script="scripts/dicom-anonymizer.script"
            quarantine="quarantine-directory" />

        <StorageService
            name="DirectoryStorageService"
            cacheID="ObjectCacheID"
            class="org.rsna.ctp.stdstages.DirectoryStorageService"
            root="roots/DirectoryStorageService"
            structure="(0010,0020)/[00080050]/0020,000D"
            quarantine="quarantines/DirectoryStorageService" />

    </Pipeline>
</Configuration>

1.1 Commentary

This section draws attention to certain attributes in the configuration and explains the reasons for them.

1.1.1 Server

The configuration file above places the CTP admin web server on port 80.

1.1.2 DicomImportService

The configuration file puts the DicomImportService on port 104.

The DicomImportService is configured not to log connections (whether rejected or not), and not to log duplicate objects that are received.

The CalledAET and CallingAET are being stored in group 0009 for future use.

1.1.3 ObjectCache

The ObjectCache is required in order to make the unanonymized values available to the DirectoryStorageService for use in defining the storage hierarchy.

The cacheID attribute is critical in this configuration. It provides a way for the DirectoryStorageService to find the ObjectCache stage and obtain the cached object containing the unanomymized values.

1.1.4 DicomAnonymizer

The configurtion file specifies the use of the same anonymization script for all objects. This can be used for testing, but for a production system handling multiple trials, a change to the DicomAnonymizer stage will be made to allow the script file to be selected based on the contents of an element. The intent is that the element will be populated by the DicomImportService based on the contents of the CalledAET or CallingAET, both of which are bering stored in group 0009 in the configuration above.

1.1.5 DirectoryStorageService

The structure attribute is configured to construct a hierarchy consisting of: PatientID/AccessionNumber/StudyInstanceUID. Files are stored by SOPInstanceUID, with no extension (e.g., ".dcm").

The cacheID attribute is critical in this configuration. It identifies the ObjectCache from which to obtain the unanonymized object.

The returnStoredFile attribute is not included in this configuration. Its default is "yes", meaning that the object passed to the next stage will point to the stored object. Since there is no next stage, this doesn't affect the flow of the pipe, but the default is used just to make the status page show the location in the store of the last object stored.

2 A Configuration File for the Image Receiver

TBD