Coerce received DICOM objects attributes by XSLT - dcm4che/dcm4chee-arc-light GitHub Wiki

Attributes of received DICOM object can be overwritten using XSLT stylesheets before they are stored to the archive. One may configure one or more XSL stylesheets depending on the requirements. To do this, one needs to create Attribute Coercions. These may be configured either on archive device level or on Archive AE extension level. One must note that the stylesheets shall always conform to Native DICOM Model

An Attribute Coercion may be created on :

• Archive Device level - to apply attribute coercion for instances received by any Application Entity of the Archive :

  Go to Menu->Configuration, then on Devices page click on Edit of the dcm4chee-arc device. Go to Extensions and Edit extension of Device Extension. Again go to its Extensions and Edit extension of Archive Device. Go to its Child objects and select + Add a new Attribute Coercion against the field Attribute Coercion. Enter the values for Name, select value for DIMSE and DICOM Transfer Role and add one or more optional values and click Save.

OR

• Application Entity level - to apply attribute coercion for instances received by this Application Entity of the Archive

  Go to Menu->Configuration, then on Devices page click on Edit of the dcm4chee-arc device. Go to its Child Objects and select an Application Entity from the Network AEs dropdown. Go to Extensions and Edit extension of Network AE Extension. Again go to its Extensions and Edit extension of Archive Network AE. Go to its Child objects and select + Add a new Attribute Coercion against the field Attribute Coercion. Enter the values for Name, select value for DIMSE and DICOM Transfer Role and add one or more optional values and click Save.

As an example, to coerce attributes when objects are stored to archive, either create a LDIF file to add attributes either on :

• Archive Device level (e.g.):

    version: 1
    # Sample configuration for Attribute Coercion        
    dn: cn=Default Attribute Coercion,dicomDeviceName=dcm4chee-arc,cn=Devices,cn=DICOM Configuration,dc=dcm4che,dc=org
    objectClass: dcmArchiveAttributeCoercion
    cn: Default Attribute Coercion
    dcmDIMSE: C_STORE_RQ
    dicomTransferRole: SCU
    dcmURI: /path-to-custom-stylesheet.xsl
  

OR

• Archive AE level (e.g.):

    version: 1
    # Sample configuration for Attribute Coercion
    dn: cn=Default Attribute Coercion,dicomAETitle=DCM4CHEE,dicomDeviceName=dcm4chee-arc,cn=Devices,cn=DICOM Configuration,dc=dcm4che,dc=org
    objectClass: dcmArchiveAttributeCoercion
    cn: Default Attribute Coercion
    dcmDIMSE: C_STORE_RQ
    dicomTransferRole: SCU
    dcmURI: /path-to-custom-stylesheet.xsl
  

and import it to the LDAP Server by using the ldapadd command line utility or the LDIF Import... function of Apache Directory Studio

• or directly use its New Entry... function to create corresponding Attribute Coercion entries. OR directly use the New Entry... function of Apache Directory Studio to create corresponding Attribute Coercion entries on Device Level (e.g.: dicomDeviceName=dcm4chee-arc) or on Application Entity Level (e.g: dicomAETitle=DCM4CHEE) of the Archive Configuration.

wherein path-to-custom-stylesheet.xsl stylesheet contains the various coercions one may want to apply on one or more DICOM attributes of incoming received objects.

One may refer to Archive Attribute Coercion to understand the description of attributes.

Go to the Control tab on Configuration page in archive UI and reload the configuration.

Depending on one's requirements, there are various examples of Attribute Coercions provided in sample configuration of archive. One may use them as it is or also modify as per one's requirement. The stylesheet may be placed on filesystem or also on http server. In below examples we are using ${jboss.server.temp.url}/dcm4chee-arc/<stylesheet>.xsl because these are packaged by default in the vendor data.

If any custom stylesheet is added, also update the Vendor Data.

• Overwrite received DICOM object's attributes from previously received HL7 Order Messages

  Merge from MWL stylesheet example

  The LDAP configuration for the same would be :

    dn: cn=Merge MWL,dicomDeviceName=dcm4chee-arc,cn=Devices,cn=DICOM Configuration,dc=dcm4che,dc=org
    dcmDIMSE: C_STORE_RQ
    dcmProperty: SendingApplicationEntityTitle=MERGE_MWL
    dicomTransferRole: SCU
    dcmMergeMWLMatchingKey: StudyInstanceUID
    dcmMergeMWLTemplateURI: ${jboss.server.temp.url}/dcm4chee-arc/mwl2series.xsl
    objectClass: dcmArchiveAttributeCoercion
    dcmNoKeywords: TRUE
    cn: Merge MWL
  

• Ensure DICOM VR Compliance of attribute values

  The attribute values in incoming DICOM objects can be corrected so that the attribute values comply with the DICOM Value Representation. The below example stylesheet corrects the attributes in the dataset which are on root level only and not inside nested datasets

  Correct VR stylesheet example

  Below table shows the corrections that shall be applied for the corresponding VRs and formats, if the example stylesheet is used..

  VR	Format	Correction
  AS	nnnD, nnnW, nnnM, nnnY	nullify
  CS	[0-9A-Z_ ]{0,16}	nullify
  DA	YYYYMMDD	nullify
  DS	Decimal String	nullify
  DT	YYYYMMDDHHMMSS.FFFFFF&ZZXX	nullify
  IS	Integer String	nullify
  LO	<= 64 chars	truncate
  SH	<= 16 chars	truncate
  TM	HHMMSS.FFFFFF	nullify

  The LDAP configuration for the same would be :

   dn: cn=Correct VR,dicomDeviceName=dcm4chee-arc,cn=Devices,cn=DICOM Configuration,dc=dcm4che,dc=org
   objectClass: dcmArchiveAttributeCoercion
   cn: Correct VR
   dcmDIMSE: C_STORE_RQ
   dicomTransferRole: SCP
   dcmProperty: ReceivingApplicationEntityTitle=CORRECT_VR
   dcmNoKeywords: TRUE
   dcmURI: ${jboss.server.temp.url}/dcm4chee-arc/correct-vr.xsl
  

• Always ensure Patient ID before storing object(s) to archive if it is missing in the received object(s)

  Ensure Patient ID stylesheet example

  The LDAP configuration for the same would be :

   dn: cn=Ensure PID,dicomDeviceName=dcm4chee-arc,cn=Devices,cn=DICOM Configuration,dc=dcm4che,dc=org
   dcmDIMSE: C_STORE_RQ
   dcmProperty: SendingApplicationEntityTitle=ENSURE_PID
   dicomTransferRole: SCU
   objectClass: dcmArchiveAttributeCoercion
   dcmNoKeywords: TRUE
   dcmURI: ${jboss.server.temp.url}/dcm4chee-arc/ensure-pid.xsl
   cn: Ensure PID
  

• Patient name not to be shown for research or test or demo purpose(s)

  Nullify Patient Name stylesheet example

  The LDAP configuration for the same would be :

   dn: cn=Nullify PN,dicomDeviceName=dcm4chee-arc,cn=Devices,cn=DICOM Configuration,dc=dcm4che,dc=org
   dcmDIMSE: C_STORE_RQ
   dcmProperty: ReceivingApplicationEntityTitle=NULLIFY_PN
   dicomTransferRole: SCP
   objectClass: dcmArchiveAttributeCoercion
   dcmNoKeywords: TRUE
   dcmURI: ${jboss.server.temp.url}/dcm4chee-arc/nullify-pn.xsl
   cn: Nullify PN