1. ACC 2001 Demonstration of DICOM Structured Reporting
Jonathan L. Elion MD, FACC
Associate Professor of Medicine
Brown University and the Miriam Hospital
Providence, RI USA Chief Medical Director and Co-Founder Heartlab, Inc., Westerly, RI USA

2. DICOM Structured Reporting
Image data represents only a fraction of the clinically useful information describing the diagnostic studies done on any individual patient. 
The American College of Cardiology’s “Structured Reporting 2001” demonstration represents the first comprehensive application of DICOM SR to information interchange in Cardiology. 
In large measure, Structured Reporting is the final, critical element in the development of a DICOM-based integration of cardiovascular information.

3. Diagnostic Procedures Network-Connected Review
DICOM: The Foundation
Diagnostic Procedures
Network-Connected Review
Stand-Alone Review
Remote Facility
DICOM SR expands DICOM capabilities beyond image management, and adds the ability to interchange additional clinical data

4. DICOM Structured Reporting
Hemodynamics
Physical Findings
ECG Reports
Consults and Notes
Other Database Information
Ultrasound Measurements
History
Codes
Standard
DICOM SR expands DICOM capabilities beyond image management, and adds the ability to interchange additional clinical data
DICOM SR

5. Customization in DICOM SR
“Presentation” – the way the data appears on the screen or printed report is not specified by DICOM SR.
DICOM SR also does not specify the user interface that is used to gather or interact with the information.
Think of DICOM SR as “Structured Data Interchange”
Finally, DICOM SR does not specify anything about the implementation of the database that underlies the data.

6. Demo System XML Standalone Viewer Web Browser XML Style Sheets
Database
DICOM Files
Web
Browser
SRGen
SRVue
Templates
A high-level overview of the data generation and display strategy for the demonstration
XML

7. DICOMDIR Source Listing
Development System
DICOM Source Listings
DCMGen
Database
Editor
build
DICOM Files
DICOMDIR Source Listing
DDGen
SRGen
DICOM SR
Source
Listing
DICOM Source Listings are used (a human-reading representation of the DICOM content)
Templates
Editor

8. Making DICOM SR for SR2001
A database of patient information was created.
Templates were created for each of the information types shown in this demonstration; ECG, Cardiac Cath, Hemodynamics, and QCA/QVA (381 lines of specs, 2599 context group items!).
A computer program (written in Java) reads a template, and combines it with its corresponding patient data. A DICOM SR file is created.
Another computer program (also written in Java) transforms a DICOM file into its XML equivalent.
Remember, we are going to generate XML via a Java routine, but…
An XML “Stylesheet” (XSL) is used to specify how the data from the XML file is to appear on the final report.
Many web browsers can show the XML+XSL directly, but for this demonstration, HTML was created.

9. Database Schema Patients Table Patient ID <more Patient data>
SR QCA Table
SOP Instance UID
Series Instance UID
<more QCA data>
SR QCA Data Table
SOP Instance UID
<more QCA data>
Studies Table
Study Instance UID
Patient ID
<more Study data>
Image Table
SOP Instance UID
Series Instance UID
<more Image data>
DICOM XA Images
Series Table
Series Instance UID
Study Instance UID
<more Series data>
SR Cath Data Table
SOP Instance UID
<more Cath data>
SR Cath Table
Series Instance UID
Some of the reports need secondary tables to hold their data

10. Templates Drive Database Schema
A row that has a VM of 1 can all live in the main data table
A template whose VM’s are all 1 corresponds to a database schema with a single (wide) row
Any row of the template that has a VM of anything other than 1 requires a secondary table
A CONTAINER with a VM that is not 1 requires a secondary table
A CONTAINER with any row that has a VM that is not 1 requires a secondary table

11. Templates: Diagram
Remember, we are going to generate XML via a Java routine, but…

12. Templates NL Relationship with Parent Value Type Concept Name VM 1
CONTAINER
Resting 12-Lead ECG Report 18
>
CONTAINS
ECG Waveform Information 23
>>
HAS ACQ CONTEXT
PNAME
Technician Name/ID 25
DATETIME
Acquisition DateTime 27
NUM
Lo Pass Filter 29
Quantitative Analysis 30
INCLUDE
Global Measurements 31
Lead Measurements 32
Qualitative Analysis 33
TEXT
Clinical Interpretation 34
Interpretive Statement
1-n
Remember, we are going to generate XML via a Java routine, but…

13. Extending Template Descriptions
Each row of the template that specifies actual data had two additional columns added:
Name of the ODBC connection for the data source (table)
Name of the field within the table that holds the data value
This connection between template and data turned out to be the single most important factor to manage for the project
As database schemas to support the templates were developed, these two columns established the connection between templates and data

14. DICOM SR from ECG
; Template ECG01 Row 25 >> VM=1 [HAS ACQ CONTEXT] DATETIME "Acquisition DateTime"
(FFFE,E000) 0xffffffff ; Item #I17
(0040,A010) "HAS ACQ CONTEXT" ; Relationship Type
(0040,A040) DATETIME ; Value Type
(0040,A043) 0xffffffff ; Concept Name Code Sequence
(FFFE,E000) 0xffffffff ; Item #I18
(0008,0100) TI ; Code Value
(0008,0102) ACC ; Coding Scheme Designator
(0008,0104) "Acquisition DateTime“
; Code Meaning
(FFFE,E00D) ; End of Item #I18
(FFFE,E0DD) ; End of Concept Name Code Seq
(0040,A120) ; DateTime
(FFFE,E00D) ; End of Item #I17
Remember, we are going to generate XML via a Java routine, but…

15. Template-Traversing Algorithm
Templates were parsed and data “pulled” to fill the required items (rather than “pushing” data out through a template).
Template specifications were expanded to include the name of the ODBC data source (table) and field name that contained the corresponding information
The algorithm was implemented using stacks to keep track of events, take non-linear processing paths 
Approach chosen for “simplicity” and ease of reading; in retrospect, a fully recursive set of procedures may be more logical and robust
Templates written in conformance with Supplement 53 are difficult to parse using a one-pass approach:
BEGIN/END blocks are not specified explicitly, but rather are inferred from nesting levels (requires look-ahead)
The occurrence of an item with VM of 1-n within a container requires “looping” for the entire container

16. Template-Traversing Algorithm
When INCLUDE found, current parsing status is pushed onto the LIFO stack; when the end of that template is reached, the status is restored from the top of the stack and scanning continues.
For rows or CONTAINERs with a VM that is not 1 the corresponding rows of the Template must be traversed multiple times (in a loop):
The same Stack is used, only this time, at the end of a pass, it's value is not popped off the stack.
Instead, its value is peeked at to find the row that represents the top of the loop. Scanning continues at that row.
This continues until eventually, the data is exhausted. When this happens (sensed at the bottom of the loop), it is time to pop the values off the top of stack (discarding them) and move on.

17. XML from ECG <Item>
<RelationshipType>HAS ACQ CONTEXT</RelationshipType>
<ValueType>DATETIME</ValueType>
<ConceptNameCodeSeq>
<CodeValue>TI-0166</CodeValue>
<CodingSchemeDesignatorACC2001</CodingSchemeDesignator>
<CodeMeaning>Acquisition DateTime</CodeMeaning>
</Item>
</ConceptNameCodeSeq>
<DateTime> </DateTime>
Remember, we are going to generate XML via a Java routine, but…

18. XSL Stylesheet for ECG
<!-- Acquisition DateTime -->
<xsl:for-each select="key('content-item', 'TI-0166')">
<b><xsl:value-of select="ConceptNameCodeSeq/Item/CodeMeaning"/>:
</b>
<xsl:value-of select="substring(DateTime, 5, 2)"/>/<xsl:value-of
select="substring(DateTime, 7, 2)"/>/<xsl:value-of
select="substring(DateTime, 1, 4)"/>,
<xsl:value-of select="substring(DateTime, 9, 2)"/>:<xsl:value-of
select="substring(DateTime, 11, 2)"/><br/>
</xsl:for-each><br/>
A “pull” approach was used for the XSL, creating a report that was “fill-in-the-blank”. Not every XML item was used (only those called for in by the report). This is like a word processor “mail-merge”
Remember, we are going to generate XML via a Java routine, but…

19. HTML for ECG
<p><center><h1>Resting 12-Lead ECG Report: Robert Johnson</h1></center></p>
<b>Clinical Context: </b>Routine<br>
<b>Acquisition DateTime: </b>10/15/2000, 11:20<br>
Remember, we are going to generate XML via a Java routine, but…

20. Integrating Information
Cath Lab Images
Online Review
History
Physical Findings
Hemo- dynamics
ECG Waveforms & Reports
Consults and Notes
Echo Images & Measurements
Digital Integrated
Cardiovascular Record!
DICOM SR expands DICOM capabilities beyond image management, and adds the ability to interchange additional clinical data

21. What’s Next?
Additional templates will be developed for Cardiology, the SR2001 templates will be refined.
These templates will be reviewed first by the interested professional organizations.
The templates will then be presented for public comment and review, and revised as needed.
The templates and Cardiology terms will be finalized and formally incorporated into the DICOM standard as “Information Object Definitions” (IOD’s)

22. Lessons Learned
Template-driven PULL processing is more complex than data-driven PUSH models (but PULL approach is probably needed for template-based SR)
Vocabulary maintenance is a very big task!
XSL for display can be more automated
Extremely helpful to have the printed documentation of the template produced directly from the database (and this tool was handy for formatting the documentation versions)
Central library for templates should be considered with web-based (Java?) editing (password protected)
WG1 has also been using diagrams to show the templates; these are hard to keep in synch with the template when changes are made; an automated approach to produce the diagrams from the templates should be considered