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<div dir="ltr">Dear gate users,
<div><br>
</div>
<div>I am reaching out to you to ask for your help concerning
a GATE simulation that I am working on at the moment. I am
trying to perform a dynamic simulation by integrating
time-activity curves (TAC) to a voxelized NEMA phantom
geometry. I use a CT image as the phantom (<i>CT.mha)</i> and
a labeled image (<i>CTMuliLabel.mha), </i>of the same size
as the phantom image, as my activity image. In order to
perform the TAC implementation I followed the example
provided on the GateContrib on <a
href="https://github.com/OpenGATE/GateContrib/tree/master/imaging/TimeActivityCurve"
target="_blank">github: https://github.com/OpenGATE/GateContrib/tree/master/imaging/TimeActivityCurve</a></div>
<div><br>
</div>
<div>However, I noticed that GATE doesn't seem to be taking
into account my TAC even though I believe to have correctly
followed the example. In my experience, Gate only seems to
consider the <i>activityRange.dat </i>file when defining the
activity and not the <i>acti.range</i> which indexes the TAC
to be used. What is weird is that while compiling the
simulation, the verbose I get in the terminal shows that the
TAC file has been read but the activity values contained in
the file are not given to the corresponding voxels. In order
to verify this, I did a simulation with and without the TAC
integration while keeping an identical seed and the
generated results are identical. Therefore, I concluded that
my simulation only takes into account the activities entered
in the <i>activityRange.dat</i> file and completely ignores
the TAC indexed in the <i>acti.range </i>file.</div>
<div><br>
</div>
<div>Linked below in the email you can find a <a
href="https://drive.google.com/drive/folders/1NeWu2e1eojkL03pUZKUqq_-9IKmK8MUN?usp=sharing"
target="_blank">link </a>to a simplified version of my
simulations with and without TAC along with the necessary
data (in the data folder). To run the simulation you simply
need to run one of the main macros:</div>
<div> - for the simulation with TAC: <i>Gate
mac/main_with_TAC.mac</i></div>
<div> - for the simulation without TAC: <i>Gate
mac/main_with_NO_TAC.mac</i></div>
<div><br>
</div>
<div>Pay attention to the fact that "total activity (Bq)"
provided by the Voxel reader verbose only takes into account
the value provided in the <i>activityRange.dat </i>(the
value in this field is obtained by multiplying the activity
provided in the <i>activityRange.dat </i>file, which is 8 Bq
for voxels with an intensity of 8, and the number of pixels
which have an intensity of 8, which are 13939 in my
example):</div>
<div><img src="cid:part3.946025A9.A4EE882D@u-bourgogne.fr"
alt="image.png" class="gmail-CToWUd" width="452"
height="87"><br>
</div>
<div><br>
</div>
<div>Other than wanting to know why the simulation doesn't
take into account the TACs, I have some other questions as
well:</div>
<div><br>
</div>
<div>1) Why do we still need the activityRange.dat file in a
dynamic setting? Since we use TACs, I do not understand the
use of using a rangeTranslator and the activityRange.dat</div>
<div><br>
</div>
<div>2) Is there a better or newer method to attribute TACs to
a voxelized geometry?</div>
<div><br>
</div>
<div>Thank you for your time.</div>
<div><br>
</div>
<div>Best regards,</div>
<div>Ben</div>
<div><br>
</div>
<div><br>
</div>
<div><a
href="https://drive.google.com/drive/folders/1NeWu2e1eojkL03pUZKUqq_-9IKmK8MUN?usp=sharing"
target="_blank">https://drive.google.com/drive/folders/1NeWu2e1eojkL03pUZKUqq_-9IKmK8MUN?usp=sharing</a></div>
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