<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
</head>
<body text="#000000" bgcolor="#FFFFFF">
<p>Hello Yeongkyeong,</p>
<p>Both PET benchmarks were indeed contain TOF data. For histogram
data, the number of events corresponds to the number of histogram
bins, and not the number of counts as for list-mode data.</p>
<p>Could you indicate what is different between the images
reconstructed from the histogram and list-mode datafiles generated
from your GATE simulation data ? The resulting images should be
identical, but there could be some small differences due to the
way the sensitivity image is computed in both case.</p>
<p>Best,</p>
<p><br>
</p>
<div class="moz-cite-prefix">On 04/01/2019 10:49, 김연경 wrote:<br>
</div>
<blockquote type="cite"
cite="mid:CA+f9Ky95zJAUocQLguRB35pgSnQFVvjynWgQu8fS0UcPa1HJsw@mail.gmail.com">
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<div dir="ltr">
<div dir="ltr">
<div dir="ltr">
<div dir="ltr">
<div dir="ltr">
<div dir="ltr">Dear, CASTor user
<div><br>
</div>
<div>First, thank you for your reply. Merlin<br>
</div>
<div><br>
</div>
<div>I reconstructed the TOF image using the benchmark
example. There were two example files.</div>
<div>One is list-mode data, and the other is
histogram-mode data.</div>
<div>However, when I looked at the header file of both
data, they were both TOF data.</div>
<div>The differences found in the two header files
were the number of events different. The number of
counts of list-mode data was about 1.5 times larger.</div>
<div>Why does this make a difference?</div>
<div><br>
</div>
<div>I compared non-TOF data obtained by Gate
simulation and converted images into list-mode and
histogram-mode, respectively. In conclusion, images
using histogram-mode data were better.</div>
<div>Could you explain the exact reason?</div>
<div><br>
</div>
<div>
<div>Any help I would really appreciate it.</div>
<div><br>
</div>
<div>Best regards,</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
<br>
<div class="gmail_quote">
<div dir="ltr">2019년 1월 4일 (금) 오전 1:05, Thibaut Merlin <<a
href="mailto:Thibaut.Merlin@univ-brest.fr"
moz-do-not-send="true">Thibaut.Merlin@univ-brest.fr</a>>님이
작성:<br>
</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px
0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
Hi Yeongkyeong,<br>
<br>
There is no additional commands to use besides /-TOF_reso/,
which will<br>
provide the assumed time resolution of the system. The TOF
measurements<br>
/dt/ for each event is computed from the time1 and time2 ROOT
variables,<br>
and the time measurement range (written in the datafile
header) is<br>
recovered during the conversion process. You could check if
the /dt/<br>
measurements in your datafile seems consistent using the<br>
castor-datafileExplorer executable with the following options
to explore<br>
the datafile event by event : /-df /path/to/datafile/header
-i -e/<br>
Depending on the ToF resolution, the convergence with ToF
correction could<br>
be much faster than with non ToF. At some point, increasing
the number of<br>
iterations would just increase the noise level, so it could be
worth to<br>
check the image you get just after a few iterations (e.g 3, 4
iterations,<br>
without subsets).<br>
<br>
Hope this helps !<br>
<br>
Kind regards,<br>
Thibaut<br>
<br>
김연경 <<a href="mailto:dusrud026@gmail.com" target="_blank"
moz-do-not-send="true">dusrud026@gmail.com</a>> a écrit :<br>
<br>
> Dear CASToR users,<br>
> <br>
> I try to reconstruct the TOF image by
converting the<br>
> root result obtained by the GATE simulation into a castor
file.<br>
> I have added the TOF_reso command and converted
the data. Do I<br>
> need any other commands besides this command?<br>
> <br>
> The command I wrote is below.<br>
> castor-GATERootToCastor -i my_data.root -m
my_data.mac -o<br>
> my_TOF_image -s my_data -TOF_reso 220. -src<br>
> In the above command, TOF image and nonTOF image
were<br>
> reconstructed using TOF_reso command. However, image
results were nonTOF<br>
> image better than TOF image.<br>
><br>
> <br>
> The commands used to create the two images are
shown below.<br>
> castor-recon -vb 2 -df
181221_nonTOF_t15_60s_jaszczak_src_df.Cdh<br>
> -fout 181221_nonTOF_t15_60_jaszczak_src -it 5:5 -dim
400,400,400 -opti<br>
> MLEM -proj joseph -conv gaussian,3.,3.,3.::psf<br>
><br>
><br>
> How can we solve it?<br>
> Any help I would really appreciate it.<br>
> <br>
> Best regards,<br>
> <br>
> Yeongkyeong KIM<br>
> <br>
> --<br>
><br>
> YEONKYEONG KIM<br>
><br>
> Molecular Imaging Research&Education
Laboratory (MIRE Lab)<br>
> Department of Electronic Engineering,Sogang University<br>
><br>
> Email : <a href="mailto:dusrud026@gmail.com"
target="_blank" moz-do-not-send="true">dusrud026@gmail.com</a><br>
</blockquote>
</div>
<br clear="all">
<div><br>
</div>
-- <br>
<div dir="ltr" class="gmail_signature">
<div dir="ltr">
<p><font face="tahoma, sans-serif" color="#666666">YEONKYEONG
KIM</font></p>
<p><font face="tahoma,sans-serif" color="#666666">Molecular
Imaging Research&Education Laboratory (MIRE Lab)<br>
Department of Electronic Engineering,Sogang University</font></p>
<p><font face="tahoma,sans-serif" color="#666666">1105,
Teilhard Hall(TE 1105), Sogang University<br>
35 Baekbeom-ro, Mapo-gu, Seoul, South Korea 121-742<br>
Tel : +82-2-713-2652<br>
Mobile : +82-10-9996-3644<br>
Email : <a href="mailto:dusrud026@gmail.com"
style="color:rgb(17,85,204)" target="_blank"
moz-do-not-send="true">dusrud026@gmail.com</a></font></p>
</div>
</div>
</blockquote>
<pre class="moz-signature" cols="72">--
Thibaut MERLIN -- PhD
Docteur en Imagerie Médicale au Laboratoire de Traitement de l'Information Medicale (LaTIM - INSERM UMR 1101)
Bâtiment 1
CHRU Morvan - 2, Av. Foch
29609 Brest CEDEX - FRANCE
Tel: 06.75.12.24.90</pre>
</body>
</html>