GATE
Download
1 / 17

GATE G eant4 A - PowerPoint PPT Presentation


  • 187 Views
  • Uploaded on

GATE ( G eant4 A pplication for T omographic E mission): a PET/SPECT general-purpose simulation platform. G.Santin (ESA-ESTEC & Trieste University) D.Strul, C.Morel (Lausanne University) (for the OpenGATE Collaboration). Imaging in Nuclear Medicine. Anatomical imaging

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'GATE G eant4 A' - daniel_millan


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

GATE(Geant4 Application for Tomographic Emission):a PET/SPECT general-purpose simulation platform

G.Santin (ESA-ESTEC & Trieste University)

D.Strul, C.Morel (Lausanne University)

(for the OpenGATE Collaboration)


Imaging in nuclear medicine
Imaging in Nuclear Medicine

  • Anatomical imaging

    • X-rays, MRI scanners, CAT, ultrasound

    • Detailed info about the tissue structure and composition

  • Functional imaging

    • In vivo physiologic analysis

    • Spatial distribution (and evolution!) of radio nuclides in the body (pharmacokinetics, metabolism)  We see the organ during its activity

    • Quantitative analysis (concentrations)

  • PET:

    • Biological molecules tagged with radioactive isotopes with short life-time (15OT1/2~2 min, 11C20 min)

    • Resolution down to a few mm3

  • SPECT:

    • Longer decay times (99mTc6 h, 123I13 h , 133Xe5 d)

      • no need for accelerator facilities

    • Poorer sensitivity (and resolution)

G.Santin GATE

  • Multimodality

    • Due to low resolution  recently often associated to other modalities of scanning (MRI, CT)


Simulations in nuclear medicine
Simulations in Nuclear Medicine

  • Wide range of applications

    • scanner design, image reconstruction, scatter correction, protocol optimization,…

  • Analytical computations

  • Since a couple of decades: accurate Monte Carlo simulations are widely used in parallel to analytical computations or experimental studies for a large range of PET and SPECT applications

    • PETsim, SimSET, EIDOLON, SIMIND, SimSPECT, SORTEO, MCMATV, PET-EGS, …

    • Non exaustive list

  • Computation time

    • Is still a concern

    • ( see later)

G.Santin GATE


Two approaches
Two approaches…

  • Dedicated simulation programs (PETsim, SimSET, Eidolon,… )

    • Simple geometry, limited number of requirements

    • Fast development

    • Optimized on application

    • Limits in the physics description

    • Maintenance, upgrades?

  • General purpose simulation codes (Geant4, EGS4, MCNP)

    • Wide community of developers and users

    • code and physics validation

    • documentation and support

    • Complexity

    • Speed

GATE

G.Santin GATE


GATE

  • Based on Geant4

    • Physics description

    • Long term availability

    • Upgrades, documentation & support

    • Object Oriented Analysis & Design

  • Extensions to build a simulation platform for PET/SPECT

    • Ease of use for non C++ programmers

      • scripting almost everywhere, geometry included…

    • Typical Nuclear Medicine options included

      • material database, sources, readout,…

G.Santin GATE

  • AND MORE !

    • Time management

    • Movements


How it works
How it works

  • 3 different layers

  • Developer level

    • Framework and application classes

    • C++ programming

  • User level

    • Simulation parameters

      • Geometry

      • Sources

    • Scripting only

User Interface

Application classes

Framework

G.Santin GATE

Geant4


Gate detailed structure
GATE detailed structure

Analysis scripting

Timing scripting

I/O choice scripting

Source scripting

Specific source type

Specific source

Specific I/O

Geometry scripting

Specific analysis

Time

mgr

Analysis mgr

Source mgr

Specific volume

G.Santin GATE

I/O mgr

Geometry mgr

Geant4

User Interface


Geometry scripting

Scanner

Source

Body

Head

Rsector

Crystal

LSO

BGO

Geometry scripting

world

G.Santin GATE

D.Strul

Uni Lausanne


Geometry examples

Collimator detail

Geometry examples

PET

SPECT

S. Staelens, Univ. Ghent

G.Santin GATE


Source management
Source management

  • Multiple sources

    • Controlled by source manager

    • Inserted via scripting

    • Complex geometries: customized GPS

  • Optimized decay

    • Customized G4 Radioactive Decay Module (RDM)

    • PET-specific sources

  • An example:

    • Dual isotope scan

    • Simulation for independent time frames

      • 0-2 and 14-16 min

G.Santin GATE


Timing

0s

20s

40s

60s

Timing

  • Simulation time

    • A clock models the passing of time during experiments

    • The user defines the experiment timing

  • Time-dependent objects

    • Updated when time changes

    • Allows programming of movement, tracer kinetics...

G.Santin GATE


Sensitive volumes and digitisation
Sensitive volumes and digitisation

  • Pre-programmed components

    • Sensitive detectors

    • Trajectory analyser

  • Digitizer

    • Linear signal processing chain

    • Modular: set-up via scripting

Hits

Digis

Energyresponse

Spatialresponse

Centroidreadout

ThresholdElectronics

G.Santin GATE


Data output
Data output

  • Pluggable output modules

    • Multiple parallel output channels ROOT, ASCII…

    • Include features for real-time display

GATE

G.Santin GATE

Output management

ASCII

ROOT

Binary format


Validation

IASA gamma camera

D. Lazaro, LPC-IN2P3, Clermont-Ferrand

Validation

  • Several SPECT/gamma camera projects

    • Clermont-Ferrand

    • Ghent

  • PET validation work to start soon

    • Lausanne, ….

G.Santin GATE


Toward parallel computation

Input file

Input file exploding

Data basefile

Database file

GATE on the Grid

Output result file

Grid-GATEoutput file

Output file merging

D. Lazaro, LPC-IN2P3, Clermont-Ferrand

Toward parallel computation

  • Computation speed is essential

    • “Simple” geometry

    • But: voxels, huge number of events, …

  • Projects

    • LAN parallelisation

    • Implementation on DATAGRID (W.I.P.)

G.Santin GATE


Opengate collaboration
OpenGATE collaboration

  • Shared development

    • Optimal use of manpower and skills

    • Long-term maintenance and support

    • Coordination of efforts

    • Multiple development axes: tool implementation, validation, …

  • Current composition

    • 10 groups

    • Fields: SPECT, PET, PET

    • Application: design, validation

  • All members contribute

    • According to their interests and know-how

    • On a best-effort basis

  • Coordination

    • A spokesman

    • Steering committee (one delegate/member)

    • Technical meetings

G.Santin GATE


Summary
Summary

  • On-going project

    • Develop a versatile simulation platform for PET/SPECT

    • Build a shared-development collaboration

    • Development and validation work on their way

  • For more info

    http://www-iphe.unil.ch/~PET/research/gate/

The End

G.Santin GATE


ad