8th Topical Seminar on Innovative
Particle and Radiation Detectors
21 - 24 October 2002
Siena, Italy
GATE
(Geant4 Applicat...
G.SantinGATE
2
Siena21Oct2002
Imaging in Nuclear Medicine
• Anatomical imaging
– X-rays, MRI scanners, CAT, ultrasound
– D...
G.SantinGATE
3
Siena21Oct2002
Simulations in Nuclear Medicine
• Wide range of applications
– scanner design, image reconst...
G.SantinGATE
4
Siena21Oct2002
Two approaches…
• Dedicated simulation programs (PETsim, SimSET, Eidolon,… )
– Simple geomet...
G.SantinGATE
5
Siena21Oct2002
GATE
• Based on Geant4
– Physics description
– Long term availability
– Upgrades, documentat...
G.SantinGATE
6
Siena21Oct2002
How it works
• 3 different layers
• Developer level
– Framework and application classes
– C+...
G.SantinGATE
7
Siena21Oct2002
GATE detailed structure
Geometry
mgr
Specific I/O
Source
scripting
Source
mgr
Time
mgr Analy...
G.SantinGATE
8
Siena21Oct2002
Geometry scripting world
Sourc
e
Body Head
Scanner
Rsector
Crystal
LSO BG
O
D.Strul
Uni Laus...
G.SantinGATE
9
Siena21Oct2002
Geometry examples
SPECT
S. Staelens, Univ. Ghent
PET
Collimator detail
G.SantinGATE
10
Siena21Oct2002
Source
management
• Multiple sources
– Controlled by source manager
– Inserted via scriptin...
G.SantinGATE
11
Siena21Oct2002
Timing
• Simulation time
– A clock models the passing of time
during experiments
– The user...
G.SantinGATE
12
Siena21Oct2002
Sensitive volumes and digitisation
• Pre-programmed components
– Sensitive detectors
– Traj...
G.SantinGATE
13
Siena21Oct2002
Data output
• Pluggable output modules
– Multiple parallel output channels ROOT, ASCII…
– ...
G.SantinGATE
14
Siena21Oct2002
Validation
• Several SPECT/gamma camera projects
– Clermont-Ferrand
– Ghent
– …
• PET valid...
G.SantinGATE
15
Siena21Oct2002
Toward parallel computation
• Computation speed is essential
– “Simple” geometry
– But: vox...
G.SantinGATE
16
Siena21Oct2002
OpenGATE collaboration
• Shared development
– Optimal use of manpower and skills
– Long-ter...
G.SantinGATE
17
Siena21Oct2002
Summary • On-going project
– Develop a versatile simulation platform for
PET/SPECT
– Build ...
Upcoming SlideShare
Loading in …5
×

talk

404 views

Published on

Published in: Technology, Health & Medicine
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
404
On SlideShare
0
From Embeds
0
Number of Embeds
3
Actions
Shares
0
Downloads
14
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide
  • Selling your ideas is challenging. First, you must get your listeners to agree with you in principle. Then, you must move them to action. Use the Dale Carnegie Training® Evidence – Action – Benefit formula, and you will deliver a motivational, action-oriented presentation.
  • http://www.irus.rri.on.ca/~pslomka/research00.html
    Nuclear Medicine is an imaging modality which provides valuable and often unique information about the function of various organs by imaging the distribution of radiopharmaceuticals inside patient’s body.
    AUTOMATED MULTIMODALITY IMAGE REGISTRATION
    Due to the low resolution of functional images (SPECT, PET ) it is desirable to integrate the functional information with the anatomical information obtained from other modalities, usually Magnetic Resonance Imaging (MRI) and Computed Tomography (CT).
    howstuffworks
    Imaging in Nuclear MedicineOne problem with the human body is that it is opaque, and looking inside is generally painful. In the past, exploratory surgery was one common way to look inside the body, but today doctors can use a huge array of non-invasive techniques. Some of these techniques include things like X-rays, MRI scanners, CAT scans, ultrasound and so on. Each of these techniques has advantages and disadvantages that make them useful for different conditions and different parts of the body. Nuclear medicine imaging techniques give doctors another way to look inside the human body. The techniques combine the use of computers, detectors, and radioactive substances. These techniques include:
    Positron emission tomography (PET)
    Single photon emission computed tomography (SPECT)
    Cardiovascular imaging
    Bone scanning
    All of these techniques use different properties of radioactive elements to create an image. See How Radioactivity works for complete details. Nuclear medicine imaging is useful for detecting:
    tumors
    aneurysms (weak spots in blood vessel walls)
    irregular or inadequate blood flow to various tissues
    blood cell disorders and inadequate functioning of organs, such as thyroid and pulmonary function deficiencies.
    The use of any specific test, or combination of tests, depends upon the patient's symptoms and the disease being diagnosed.
    Single Photon Emission Computed Tomography (SPECT)SPECT is a technique similar to PET. But the radioactive substances used in SPECT (Xenon-133, Technetium-99, Iodine-123) have longer decay times than those used in PET, and emit single instead of double gamma rays. SPECT can provide information about blood flow and the distribution of radioactive substances in the body. Its images have less sensitivity and are less detailed than PET images, but the SPECT technique is less expensive than PET. Also, SPECT centers are more accessible than PET centers because they do not have to be located near a particle accelerator.
  • talk

    1. 1. 8th Topical Seminar on Innovative Particle and Radiation Detectors 21 - 24 October 2002 Siena, Italy 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)
    2. 2. G.SantinGATE 2 Siena21Oct2002 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 (15 OT1/2~2 min, 11 C20 min) – Resolution down to a few mm3 • SPECT: – Longer decay times (99m Tc6 h, 123 I13 h , 133 Xe5 d) • no need for accelerator facilities – Poorer sensitivity (and resolution) • Multimodality – Due to low resolution  recently often associated to other modalities of scanning (MRI, CT)
    3. 3. G.SantinGATE 3 Siena21Oct2002 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)
    4. 4. G.SantinGATE 4 Siena21Oct2002 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
    5. 5. G.SantinGATE 5 Siena21Oct2002 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,… • AND MORE ! – Time management – Movements
    6. 6. G.SantinGATE 6 Siena21Oct2002 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 Geant4
    7. 7. G.SantinGATE 7 Siena21Oct2002 GATE detailed structure Geometry mgr Specific I/O Source scripting Source mgr Time mgr Analysis mgr I/O mgr Geometry scripting I/O choice scriptingSpecific source type Specifi c source Geant4 Specifi c analysi s Analysis scripting Timing scripting Specifi c volume User Interface
    8. 8. G.SantinGATE 8 Siena21Oct2002 Geometry scripting world Sourc e Body Head Scanner Rsector Crystal LSO BG O D.Strul Uni Lausanne
    9. 9. G.SantinGATE 9 Siena21Oct2002 Geometry examples SPECT S. Staelens, Univ. Ghent PET Collimator detail
    10. 10. G.SantinGATE 10 Siena21Oct2002 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 15 O and 11 C 0 1000 2000 3000 4000 5000 6000 7000 0 5 10 15 20 25 time (min) counts
    11. 11. G.SantinGATE 11 Siena21Oct2002 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... 0s 20s 40s 60s
    12. 12. G.SantinGATE 12 Siena21Oct2002 Sensitive volumes and digitisation • Pre-programmed components – Sensitive detectors – Trajectory analyser • Digitizer – Linear signal processing chain – Modular: set-up via scripting Hits Energy response Spatial response Centroid readout Threshold Electronics Digis
    13. 13. G.SantinGATE 13 Siena21Oct2002 Data output • Pluggable output modules – Multiple parallel output channels ROOT, ASCII… – Include features for real-time display Output management ASCII ROOT Binary format GATE
    14. 14. G.SantinGATE 14 Siena21Oct2002 Validation • Several SPECT/gamma camera projects – Clermont-Ferrand – Ghent – … • PET validation work to start soon – Lausanne, …. D. Lazaro, LPC-IN2P3, Clermont-Ferrand IASA gamma camera
    15. 15. G.SantinGATE 15 Siena21Oct2002 Toward parallel computation • Computation speed is essential – “Simple” geometry – But: voxels, huge number of events, … • Projects – LAN parallelisation – Implementation on DATAGRID (W.I.P.) Input file Data base file Input file exploding Output file merging Grid- GATE output file Output result file GATE on the Grid Data base file D. Lazaro, LPC-IN2P3, Clermont-Ferrand
    16. 16. G.SantinGATE 16 Siena21Oct2002 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, µPET – 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
    17. 17. G.SantinGATE 17 Siena21Oct2002 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

    ×