Mapping, registration and atlases IMAGE workshop breakout group Members of group • • • • • • • Derek Hill, London Richard Baldock, Edinburgh Dave Berry, Edinburgh Tilak Ratnanather, Baltimore Xavier Pennec, Nice Denise Ecklund, Edinburgh Vincent Breton, Clermont Ferrand Aims of breakouts • To generate written report about issues • Make recommendations for future work • Highlight areas that might benefit from future research funding • Make links with industrial activity • Facilitate international collaboration Breakout group sub-headings • How do we make image registration grid services intraoperable? • Can the grid provide a technology push? • How should we represent mappings? • Should we use grid-services for a major cross validation of algorithms? • How can, or should,atlases be shared? • How could these services be used commercially (eg: for drug discovery) • What user interaction is required? • Statistics of mappings • How do we make image registration grid services intraoperable? – Do we need to devise an abstract model for these services? • Eg: what is a spatial transformation • ITK is going some of the way in this direction and illustrates some of the difficulties • Can the grid provide a technology push – New techniques that simultaneously analysis cohorts – Treating time better – User interaction • How should we represent mappings? – Definition of coordinate systems – Representing diffeomorphisms and other types of mappings – Do we need an ontology? • Should we use grid-services for a major cross validation of algorithms? – Compare with 1995 retrospective registration evaluation project which used ftp for international multicentre collaboration – Do you need a “gold standard” to do this? – Could we share the necessary data internationally? • Two approaches: – Test algorithms against standard data including sensitivity to data perturbations – Test data against algorithms • Who would pay for CPU cycles? • Compare results of new algorithms with those of established algorithms eg: SPM • How can, or should, atlases be shared? – Component data for atlas – Algorithms that form part of atlas • We need to carefully define what we mean by an atlas – Is there an agreed definition for a static atlas? – Is it an evolving representation of the state of knowledge • How could these services be used commercially (eg: for drug discovery) – Regulatory approval? – The grid could provide access to established validated algorithms – Mechanisms for licensing s/w on a per-use basis. User interface • A user interface will be needed to interact with the algorithm – Set parameters, use best practice parameters – Customize to application – Interact with the registration process, eg: to add prior knowledge about corresponding features • Tutorials • Visualization of results: how do we visualize mappings (application specific) • Mapping statistics – Statistics on deformations might be part of an atlas How do we overlap with other groups • Visualization and data exploration – We need visualization tools for interaction and viewing results/metrics • Image analysis, measurement and query – How do we use queries to reason with mappings generated by regn. algorithms? – Metrics from mappings – Metrics from registered images • Data management, metadata, ontologies, provenance – We obviously need all of this stuff! Issue of generalization • Almost all headings in “registration” could be applied to other image analysis techniques eg: segmentations Future work of this group • Select sub-headings for detailed discussions leading to recommendations • What is easy to do, not easy to do, or dependent on other activity? • Can we identify the state-of-the-art in these areas? • Can we facilitate international collaboration? • Link our aspirations to the current state of grid technology A registration test bed ? • Registration is a core technology in medical image analysis • There is no one algorithm that solves all problems • There continues to be substantial algorithm development • Registration needs to fit into many different image analysis workflows Scenario 1 • Prototyping a new application – – – – New sort of data New question Want to find the right algorithm Grid can be used to do large scale comparison of different algorithms Scenario 2 • “Production” image registration service – Provides easy use for customers • Application scientists eg: clinical research fellow • Companies (eg: pharma) • Healthcare organisations Scenario 3 • Cross validation – Grid services providing image registration – Reference datasets – Definition of how to to add a new registration service or new data – Can be used by researchers to compare algorithms prior to publication – Challenges to compare algorithms on new problems, eg: one brought by a pharma company, new algorithms Scenario 0 • To build a grid application to enable comparison of registration algorithms • Limited grid demonstrator – Loose collaboration of resources, algorithms and researchers – At least 3 algorithms – At least 3 data repositories (?include pathology) – At least 3 compute resources – At least 3 research teams – Demonstrate expandability, heterogeneity Obstacles • Image file formats – We could use the DICOM core fields • Access to grid infrastructure – Hardware – Support and training to set it up • Architecture – Coordination – Portal – registry More Obstacles • Transformation format – Could initially provide tutorial, example standard transformation, i/o libraries – Should we have a minimum subset of data eg: vector field of resolution of original target image – Origins etc… • How do you quantify differences between algorithms? • Security and confidentiality – We would start with anonymised data for which suitable consent had been obtained Way forward • We want to keep it small so that things can happen for scenario 0. • We could keep it small by proposing it is initially done with no funding. • This needs to be application lead • The primary aim is to answer scientific questions about image registration Partners and Roles • INRIA linux cluster, – already has a PhD student working on parallellising registration algorithm, – could probably generate interest in putting this on the grid. • KCL & Imperial (IXI) – Already implementing registration service • NESC – Could assist with registry and portal (a month or so of effort to do something) • Hopkins • Supercomputer on the grid running registration • Others to give global coverage Timetable • Set up email list – Sept 2003 • Invite key application groups to meeting at MICCAI 2003, Montreal in November 2003 • Initial demonstration of concept, and description of project for eHealth in January 2004 • Need a grid technology support from NESC and Clermont Ferrand