DICOM

1
Modellizzazione DICOM in Geant4
Gruppo italiano MC-INFN
Stéphane Chauvie
Santa Croce e Carle Hospital, Cuneo
2
DICOM example in Geant4

• Developed in 2002
• L. Archambault, L. Beaulieu, V.-H. Tremblay
  (Univ. Laval and l'Hôtel-Dieu, Québec)
• Donated to Geant4 for the common profit of the
  scientific community
• under the condition that further improvements and
  developments are made publicly available to the
  community
• Released with Geant4 5.2, June 2003 in an
  extended example
• with some software improvement by S. Guatelli and
  M.G. Pia
• Navigation functionalities
• Pedro Arce (CIEMAT, Madrid)
• Update and maintained
• Pedro Arce (CIEMAT, Madrid)
• Stéphane Chauvie (Santa Croce e Carle Hospital
  INFN, Cuneo Torino)

/examples/extended/medical/DICOM
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extended example Navigation

• Is the only example in GEANT4 to offer 4
  different navigation functionalities
• The 1D optimisation
• It will be very slow because each time a track
  exits a voxel it has to loop to all other voxels
  to know which one it may enter
• The 3D optimisation with G4SmartVoxel
• a 3D grid is built, so that the location of
  voxels is fast, but it requires a lot of memory
• Using G4NestedParameterisation
• The search is done hierarchically in X, Y and Z.
  It is fast and does not require big memory
• Using G4PhantomParameterisation/G4RegularNavigatio
  n
• A special algorithm to navigate in regular
  voxelised geometries (see GEANT4 doc). This is
  the fastest way without any extra memory
  requirement (and it is the default in this
  example). It includes an option (default) to skip
  frontiers between voxels when they have the same
  material.

4
extended example DICOM interface

• Reading image information
• Transformation of pixel data into densities
• Association of densities to a list of
  corresponding materials
• Defining the voxels
• Geant4 parameterised volumes
• parameterisation function material

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HU to material
Interfaccia DICOM
Tessuti molli - relazione CT-tessuto ICRU
Osso - linearità CT-?el - diluizione osso-midollo
Polmone linearità CT-?
6

• Ti ho inserito anche la diapositiva di come fanno
  in Fluka
• Bisogna ovviamente farla vedere ad uno di loro ma
  magari può essere un ambito dove creare siergie
  tra i due gruppi
• Ciao

7
Fluka
writegolem.f
NB No reading CT of variable thickness
27 HU intervals and materials (Schneider) defined
trough elemental composition and nominal mean
density (density corresponding to the HU value at
the centre of the considered interval) -1000 a
-120 9 materiali same compostion but different
nominal density UHgt1600 come Schneider HUgt3600
metallic implants
CORRFACT to account for nuclear and
electromagnetic interaactions (ratio of stopping
power)
Phys. Med. Biol. 52 (2007) 33693387 Clinical
CT-based calculations of dose and positron
emitter distributions in proton therapy using the
FLUKA Monte Carlo code K Parodi1,3, A Ferrari2, F
Sommerer2 and H Paganetti1
Journal of Physics Conference Series 74 (2007) A
MC tool for CT-based calculations of dose
delivery and ß-activation in proton therapy K
Parodi1,3, A Ferrari2, F Sommerer2 and H
Paganetti1