9.4.2008

DICOM International Conference & Seminar

Work Item Implants – Current State and Outlook

Michael Gessatmichael.gessat@iccas.de

Thomas Trommer, Armin Löpfe, Oliver Burgert

2Outline

Implant Templates and Implantation Planning

Motivation

Features

Information Models

Examples

3Implant Templates & Implantation Planning

The pre-operative selection of the most suitable implant and the determination of the optimal position and fixation of an implant in the patient’s body is called implantation planning.

Planning is done with radiological images and graphical representations of implants, called implant templates.

4Implant Templates & Implantation Planning

5Motivation

PACS Server

Vendor Template Repository

Planning Workstation

Patient Images

Implant Templates

Planning Report

Required Templates

Intraoperative SystemPatient Images

HISEHR Data

At present: No standardized semantics and syntax for implant

templates No standardized format for planning results No integration of information flow into PACS

6Motivation

Patient Images

Implant Templates

Planning Report

Required Templates

Intraoperative SystemPatient Images

HISEHR Data

Planning Report

Required Templates

PACS Serverincl. Temp. Rep.

Planning Workstation

Our goal: Implant templates standardized in DICOM Implantation plans standardizes in DICOM All data stored in PACS server Whole data is exchanged via PACS

7Required Concepts

Patient‘s Morphology X-Rays, CTs, 3D Ultrasound Segmentation and Classification

Implant Geometry 2D 3D

Result Simulation Biomechanical properties Tissue deformation

Transfer into the OR Network technology & Displays Transfer protocols and formats

8DICOM Sup. 131 and 134

Bone MountedImplants

ImplantsImplantsImplantsImplants

Stents, Valves, … Many more

HipHip ShoulderShoulder DentalDentalSpineSpine Middle EarMiddle Ear

Implant Repository:Implant Repository:Bone Mounted Implant Template Storage

SOP Class

Patient Specific Plan / Report:Patient Specific Plan / Report:Implantation Plan Document SOP Class

General SurfaceMesh Module

EncapsulatedHPGL 2

Based on SR

9Workshops

In workshops with representatives from the implant industry and implantation planning software industry. Leipzig, December 13, 2007 San Francisco, March 3, 2008

A set of features and attributes was elaborated.

Working Group 24 is working on the translation of the workshop results into DICOM Supplements.

In parallel, ICCAS works on a test implementation of the new DICOM SOP Classes.

10Features

Implant Templates contain 2D and/or 3D representation, contain (anatomical) landmarks for

registration with patient images, contain information about indication, and can consist of several components,

Component assembly is described:compatibility,geometric constraints, and degrees of freedom.

11Information Model - Implant Templates

Implant

Component

1

1-n

Surface ModelFiducial

Manufacturer

Frame of Reference

11-n

11-n

1

0-n

Contact

0-n 1-naccepts

has has has

spatially defines

produces

consistsof

1

0-n

1

0-1

2D Template

has

1

0-n

12Example

Component 1“Hip Joint Head”“Material: Porcelain”Contact 1

CoordinatesAxesLink: Comp. 2, CP 1

Component 2“Hip Joint Shaft”“Material: Titan”Contact 1

CoordinatesAxesLink: Comp. 1, CP 1

Fiducial 1Femur Axis

13Implant Types

Implants for different purposes differ very much in the Attributes and landmarks that describe them.

We propose an encoding mechanism that leaves room for a lot of flexibility.

Only the Attributes that are applicable to the type of implant that is described in one Instance need to be present.

General Implant Attributes Hip Joint

Assembly

Dental Implant

14Implantation Plan SR Document: Features

Registration

Templates (Implant Components)

Patient Image VisualizationAnatomical

Fiducials

Implantation Plan Assembly

description

Planning Information

Derived Fiducials

Images: ENDOTEC

15Information Model - Implantation Plan SR Document

Implant IOD

Surface ModelFiducials

Implantation Plan SR

contains

references

Registration IOD

Image IOD

Surface Seg. IOD

Spatial Fiducials IOD

refers to

spatiallyaligns

2D Templates

9.4.2008

Acknowledgements

The Innovation Center Computer Assisted Surgery (ICCAS) at the Faculty of Medicine at the University of Leipzig is funded by the German Federal Ministry for Education and Research (BMBF) and the Saxon Ministry of Science and the Fine Arts (SMWK) in the scope of the initiative “Unternehmen Region” with the grant numbers 03 ZIK 031 and 03 ZIK 032.

Gefördert im Rahmen der Technologieförderung mit Mitteln des Europäischen Fonds für regionale Entwicklung (EFRE) und mit Mitteln des Freistaates Sachsen.

Thank you very much for your attention!