[Gate-users] CT import for voxelized phantom

[Nada Fakhoury]

Dear all,

I have been struggling with an issue for quite some time now and I  
cannot seem to find a solution for it.
The issue is when trying to create a voxelized phantom from a  
patient's CT, I get an error for out of range Hounsfield Units from my  
CT file:

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|
|GateVImageVolume.cc (l.365):  I find H=8448 in the image, while  
Hounsfield range stop at 3000
|
|

I have tried to "override" this problem by simply expanding the range  
and then of course my simulation runs.
However, even though it works on my build, on my laptop, when I try to  
run it on the GateLab cluster, I get another error, this time in the  
HounsfieldMaterialTable.cc:

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|
|GateHounsfieldMaterialTable.cc (l.127): Current H1=-1050 is different  
from previous H2=-32768. Abort.
|
|

Now, the problem is that the only time I actually managed to run my  
simulation with a CT-based phantom was when I used the .mhd file  
provided in the Gate radiotherapy examples, instead of the .hdr ones  
generated by the CTs I have.

At first I thought I probably should change the HU range, but in my  
Dicom files the HU conversion is the default one..

Note that this problem arose in every version of Gate I installed,  
whether it was 6.2, 7.0 or 7.1.. I've tried to use every solution I  
could find on the user's list archive..

May it be that something goes wrong when I convert it from dicom to  
.hdr? (I use ImageJ for this)

I tried converting it to .mhd but then I get again the same problem..

|
|
|GateVImageVolume.cc (l.365):  I find H=63488 in the image, while  
Hounsfield range stop at 3000.
|
|

I also tried importing CTs from different modalities, but I still have  
no luck..

If anyone has any thoughts, I'd really appreciate the help.


Thank you in advance for any feedback.

Nada
-- 
Nada Fakhoury
MSc "Medical Physics" Student