[Gate-users] Usage of voxelized geometry (hdr/img)

[刘斌信件]

hi,
    I want to use voxelized geometry  as tumor phantom , Step 1 : Get an initial CT image . Get a CT image (generally in DICOM format) and convert it to a 3D image format [Analyze hdr/img format] .  I use MRIConvert-2.0.4-win32 (not Vv)  convert CT image (DICOM format ) to Analyze hdr/img  3D image. 

First ,the one slice of CT image information :
Title: CT24.dcm
Width:  550.00 mm (512)
Height:  550.00 mm (512)
Resolution:  0.931 pixels per mm
Pixel size: 1.07x1.07 mm
ID: -8
Coordinate origin:  0,0
Bits per pixel: 16 (signed)
Display range: -20 - 80
No Threshold
 
Calibration Function: y = a+bx
  a: -32768.000000
  b: 1.000000
  Unit: "Gray Value"
Path: F:\RT\ysrCT2.5\CT24.dcm

Second, the converted hdr/img file  by MRIConvert  information :
Title: 20120220_YANG_SHU_REN____20120214_8025_002_1_1_Head_Helical_5mm.img
Width:  550.00 pixels (512)
Height:  550.00 pixels (512)
Depth:  172.50 pixels (69)
Resolution:  0.931 pixels per pixel
Voxel size: 1.07x1.07x2.50 pixel
ID: -10
Coordinate origin:  0,0,0
Bits per pixel: 16 (unsigned)
Display range: 30768 - 35030
Frame: 1/69
Frame interval: 0.00000 sec
No Threshold
Uncalibrated
Path: C:\Documents and Settings\Administrator\desktop\20120220_YANG_SHU_REN____20120214_8025_002_1_1_Head_Helical_5mm.img
No Selection

At last , to insert an image I  use  following command :
          /gate/world/daughters/name patient
          /gate/world/daughters/insert ImageNestedParametrisedVolume
          /gate/patient/geometry/SetImage data/patient.hdr
          /gate/geometry/setMaterialDatabase data/patient-HUmaterials.db
          /gate/patient/geometry/SetHUToMaterialFile data/patient-HU2mat.txt 

However   there is  a error output :  src/GateHounsfieldMateriaTable.cc(l.129): Current  H1=-1050 is different  from previous H2=-2000. Abort .  
I think that the H2=-2000  is a obvious  error ,because the minimal HU value  is -1050 to Air.

     I want to know that how Gate to convert hdr/img  3D image value to  HU ,  Can  I  use MRIcro or MRIConvert deal with  CT image ?
Best wishes,
Bin.