Lawrence Tarbox, Ph.D. Washington University in St. Louis School of Medicine Mallinckrodt Institute of Radiology, Electronic Radiology Lab

Provocative Statement DICOM WG-23 hopes to fundamentally change the way the medical imaging world thinks in regards to the distribution and deployment of medical imaging applications.

Status Quo  Medical imaging workstations generally are closed systems.  There is no common, standardized method for adding new functionality to a medical workstation.  The key stakeholders who wish to see new functionality added often are not the workstation provider.  New ‘cool’ tools often require adding entire workstations to a site’s infrastructure.

From the SIIM 2007 Workflow Demonstrations  Cardio Workflow – Dr. Anwer Quershi “… going back and forth to various workstations and the use of different equipment is disruptive and slows treatment …”  Nuclear Workflow – Dr. Eliot Siegel “... This case illustrates the disruptions that can be introduced due to multiple systems and the need to go back and forth....”

A Brave New World? Separate the provision of infrastructure from the application.  Infrastructure providers concentrate on the movement and storage of data and results, and on workflow management.  Application providers concentrate on the processing and analysis of that data, providing results back to the infrastructure. Minimize the ‘reinvention of the wheel’.

Proposed Solution  Create a mechanism where applications written by one party could be launched and run on systems created by multiple other parties.  Allow launched applications to efficiently access images and other resources controlled by the hosting system.  Provide a framework for exchanging information about those applications.  Support both research and clinical environments.

Typical Plug-in Concept … A E BCD F

DICOM WG-23 Goal Portable applications that ‘ plug into ’ any host that implements the standardized ‘ socket ’ Syngo Cedara caBIG Advantage Agfa any WG23 Host

Idealized Goals A Standardized API that is:  Easy to learn and use  Language independent  Platform independent  Based on publicly available technology  Extensible  Secure

Reality Check “Life is a compromise”  Language and platform independence often translates into reduced performance.  Choice of development environment often restricts portability. The real goal is to come as close to the ideal as practical, and minimize the impact where we fall short. Take one step at a time.

Suggested Staging  Stage one – Access to DICOM Datasets and Results Recording  Stage Two – Access to Non-Interactive Application Services (e.g. print, archive)  Stage Three – Access to Interactive Application Services (e.g. GUI, ‘skins’, rendering)  Stage Four – Standard Workflow Descriptions, and Interactions Between Hosted Software

Targets for Stage One  Basic Launch and Control of a Hosted Application  Load, Unload, Start, Abort  Simple Interchange of Data Between a Hosting System and Hosted Applications  File-based data exchange for existing applications  Model-based data exchange for new applications  Manual Configuration  Java and.net technology bindings

Model-Based Data Exchange Data Objects Conversion Bulk Data (e.g. voxels) Abstract Data Subset Full Native Data

Abstract vs. Native Models  Abstract Models  Includes data common to multiple formats (e.g. DICOM, Analyze)  Application need not know the format of the native data  Does include references to the native data from which the abstract model was derived  Native Models  Gives full access to all information available in the native data  Allows an application to just access those parts of the native data that are of interest  Bulk Data Access  File name (URI) plus offset (for performance)

Pushing for Adoption  Standardization being done via DICOM with participation from both medical imaging vendors and users  Open-source, commercial friendly reference implementation being created  XIP – the eXtensible Imaging Platform  WG-23 participants (vendors and the XIP developers) exchange test implementations to insure interoperability

WG23 / XIP Relationship WG-23 addresses clinical integration and vendor inter-operability by defining standardized “plugs” and “sockets” (APIs) WG-23 addresses clinical integration and vendor inter-operability by defining standardized “plugs” and “sockets” (APIs) caBIG XIP addresses an open- architecture, open-source, integrated environment for rapid application development based on WG 23 APIs caBIG XIP addresses an open- architecture, open-source, integrated environment for rapid application development based on WG 23 APIs Unix, Mac, PCInternet ServerCommercial Vendor #2 … Commercial Vendor #1  Clinical   Prototype & Collaboration  XIP developed Application Standard API

 The eXtensible Imaging Platform (XIP™) is the image analysis and visualization tool for caBIG.  XIP is an open source environment for rapidly developing medical imaging applications from an extensible set of modular elements.  XIP may be used by vendors to prototype or develop new applications.  Imaging applications developed by research groups will be accessible within the clinical operating environment, using a new DICOM Plug-in interface first implemented in XIP.  XIP serves as a reference implementation of the DICOM WG-23 Application Hosting interfaces. What is the ?

Major Parts of the  XIP Reference Host  XIP Libraries  XIP Reference Applications  XIP Development Tools The top 3 combine to form an XIP Workstation

XIP Application (Can be replaced with any DICOM WG23- compatible Host) XIP Host Adapter XIP Modules Host Independent WG 23 XIP Host WG 23 Web-based Application Medical Imaging Workstation Standalone Application Distribute DICOM, HL7, & other services per IHE caGRID Services via Imaging Middleware XIP Application Builder XIP Class Library Auto Conversion Tool Host-Specific Plug-in Libs WG 23 Distribute ITKVTK XIP LIB... XIP Development Process

An Application Developer may use the XIP Builder tool from Siemens Corporate Research to create the app’s scene graph and processing pipelines from XIP Libraries

The XIP Builder tool can be used to test and debug the scene graph

Application Developer controls the scene graph by creating a GUI program (e.g. via Java Swing)

Provides the infrastructure in which XIP or DICOM WG-23 Applications run Authenticates user Manages installation, launching, and termination of XIP Applications Provides data and services to XIP Applications Accepts status information and results back from XIP Applications Deals with auditing and controls access to services and data Isolates the XIP application from the nature of databases, archives, networks, and possibly image data formats Manages access to DICOM networks, objects, and services Creates Abstract Models from input data Handles workflow issues IHE General Purpose Worklist support Supports any application that follows the DICOM WG-23 Application Hosting Interface Standard

Summary  XIP provides the ability to create rapidly create applications customized to specific tasks.  The DICOM WG-23 Application Hosting interfaces allow those applications to run on any workstation that supports the standard interfaces  XIP includes a reference host implementation  Other vendors may eventually host applications  XIP with DICOM WG-23 represent new paradigm for writing and distributing medical imaging applications