The need for an API:
The need for an API SR is primarily encoded in DICOM
DICOM parsing/encoding requires tools
May need transcoding into XML, HL7 …
Input methods, rendering rules essentially independent of encoding
Standard API to separate encoding from applications
Transcoding Applications:
Transcoding Applications …
(0x0040,0xa491) <COMPLETE>
(0x0040,0xa493) <VERIFIED>
(0x0040,0xa730) Content Sequence
(0x0040,0xa010) <HAS OBS CONTEXT>
(0x0040,0xa040) <PNAME >
(0x0040,0xa043) Concept Name Code Sequence
(0x0008,0x0100) <000555>
(0x0008,0x0102) <LNdemo>
(0x0008,0x0104) <Recording 0bserver>
(0x0040,0xa123) <Smith^John^^Dr^ >
... <contentsequence>
<contentitem>
<contentlabel>1.1</contentlabel>
<relationshiptype>HAS OBS CONTEXT</relationshiptype>
<conceptname>
<codesequence>
<codevalue>000555</codevalue>
<codingschemedesignator>LNdemo</codingschemedesignator>
<codemeaning>Recording Observer</codemeaning>
</codesequence>
</conceptname>
<valuetype>PNAME</valuetype>
<personname>Smith^John^^Dr^</personname>
</contentitem>
<contentitem> DICOM Internal XML
Rendering Applications:
Rendering Applications …
(0x0040,0xa491) <COMPLETE>
(0x0040,0xa493) <VERIFIED>
(0x0040,0xa730) Content Sequence
(0x0040,0xa010) <HAS OBS CONTEXT>
(0x0040,0xa040) <PNAME >
(0x0040,0xa043) Concept Name Code Sequence
(0x0008,0x0100) <000555>
(0x0008,0x0102) <LNdemo>
(0x0008,0x0104) <Recording 0bserver>
(0x0040,0xa123) <Smith^John^^Dr^ >
... <contentsequence>
<contentitem>
<contentlabel>1.1</contentlabel>
<relationshiptype>HAS OBS CONTEXT</relationshiptype>
<conceptname>
<codesequence>
<codevalue>000555</codevalue>
<codingschemedesignator>LNdemo</codingschemedesignator>
<codemeaning>Recording Observer</codemeaning> Parser A Parser B Common API Report of Chest X-Ray (PA and LateralViews)
Patient Jane Homer
Study # 123456
Recorded by Dr. John Smith
The finding is a mass measuring 1.3 cm in diameter with an infiltrative margination. Chest X-Ray
has concept modifier Views=PA and Lateral
Recording Observer=Smith^John^^Dr^
Study Instance UID …=1.2.3.4.5.6.7.100
Patient-Data-Acquisition-Subject=Homer^Jane^^^
Finding=Mass
has properties diameter=1.3 cm
has properties margination=infiltrative (1.4.2) Display C Display D DICOM XML
Input Applications:
Input Applications …
(0x0040,0xa491) <COMPLETE>
(0x0040,0xa493) <VERIFIED>
(0x0040,0xa730) Content Sequence
(0x0040,0xa010) <HAS OBS CONTEXT>
(0x0040,0xa040) <PNAME >
(0x0040,0xa043) Concept Name Code Sequence
(0x0008,0x0100) <000555>
(0x0008,0x0102) <LNdemo>
(0x0008,0x0104) <Recording 0bserver>
(0x0040,0xa123) <Smith^John^^Dr^ >
... <contentsequence>
<contentitem>
<contentlabel>1.1</contentlabel>
<relationshiptype>HAS OBS CONTEXT</relationshiptype>
<conceptname>
<codesequence>
<codevalue>000555</codevalue>
<codingschemedesignator>LNdemo</codingschemedesignator>
<codemeaning>Recording Observer</codemeaning> GUI A NLP B Common API Report of Chest X-Ray (PA and LateralViews)
Patient Jane Homer
Study # 123456
Recorded by Dr. John Smith
The finding is a mass measuring 1.3 cm in diameter with an infiltrative margination. Encoder C Encoder D
Tree rewriting:
Tree rewriting Specific Application
Tree rewriting:
Tree rewriting Rules in pattern language Generic Application
Precedent in XML World - DOM:
Precedent in XML World - DOM Document Object Model (W3C rec.)
Parse an XML document
Validate against DTD
Represent as tree
Multi-language bindings for accessor methods
Edit/generate tree elements
Write out as an XML document
SR - why not just use DOM ?:
SR - why not just use DOM ? Structure of the SR tree slightly different
Node content different
Constraints on value types different
XML - just PCDATA
SR - PNAME, NUM, IMAGE, SCOORD etc.
SR Object Model (SR-OM) API:
SR Object Model (SR-OM) API Follow DOM as closely as possible
Generic specification in IDL
Multiple language bindings
C++
Java
ECMAScript, Python, ...
Accessor methods rather than generic collections (STL, Java 2 Collections)
SR-OM Classes and Interfaces:
SR-OM Classes and Interfaces interface SRDocument {
SRNode getRootNode();
};
interface SRNode {
String getConceptName();
SRValueType getValueType();
SRValue getValue();
…
SRNode getParent();
SRNode getFirstChild();
SRNode getNextChild();
…
};
SR-OM Decisions:
SR-OM Decisions Is DOM concept sufficient ?
other XML API approaches
SAX - event driven tree traversal
Accessors
Iterators: getNextChild()
Indexed: getNamedChild(ConceptName)
Validation a separate interface ?
SR-OM Home:
SR-OM Home DICOM Working Group home ?
WG 8 SR, WG 6 Base Standard, new WG ?
Joint effort with HL-7 (WG 20)
Vendor concensus (ad hoc group) ?
Document home ?
DICOM Standard ?
DICOM Recommendation ?
Ad hoc concensus document