[Castor-users] SPECT reading Interfile

Carlier Thomas thomas.carlier at chu-nantes.fr
Mon Apr 24 18:34:24 CEST 2017


Dear Michael,


The attenuation coefficient is in cm-1 as explicitly specified in the 
manual. The attenuation map was extracted directly from the Siemens 
computation which uses (as you assume) a wide beam approach. The correct 
value should be the one you mention for the methodology used by CASToR. 
I apologize for this misunderstanding and a correct mu-map will be 
uploaded soon.

Thanks for pointing out this small error.


Best regards


Thomas Carlier


Le 19/04/2017 à 16:42, Michael Ljungberg a écrit :
>
> Dear Simon and Didier
>
> Thank you for your comments and information. I have now written a 
> conversion program between simind interfiles and castor and I can 
> reconstruct images :-) . I have a final question for the moment and 
> that concerns the units of the mu map. I assume it is mu (cm-1) for 
> the current photon energy. When I looked at the SPECT benchmark file 
> the average value in a ROI is however, around 0.128 cm-1 instead of 
> 0.154 which is this the linear attenuation coefficient for water. Is 
> this an ‘effective attenuation coefficient map’ with lower values with 
> the purpose of compensate for presence of scatter? I just want to be 
> clear about what values the mu-map should reflect.
>
> Hälsningar / Best regards
>
> Michael
>
> *From: *Castor-users <castor-users-bounces at lists.castor-project.org> 
> on behalf of Simon Stute <simon.stute at cea.fr>
> *Date: *Tuesday, 18 April 2017 at 17:26
> *To: *"castor-users at lists.castor-project.org" 
> <castor-users at lists.castor-project.org>
> *Subject: *Re: [Castor-users] SPECT reading Interfile
>
> Hello,
>
> The castor configuration folder also contains other configuration 
> files, so it is not only related to the scanner geometries.
>
> However, a third possibility is to copy the whole 'config' folder (it 
> is light) into your working directory, put your geom files inside the 
> 'scanner' sub-folder and then you can use the '-conf 
> ./your_config_folder' option to overload the path of the configuration 
> directory at run-time.
>
> The '-conf' option is described when calling 'castor-recon -help-misc'.
>
> Regards
> Simon
>
>
> Le 18/04/2017 à 17:13, Didier Benoit a écrit :
>
>     In our software, we didn't plan to read the .geom files in 2 or
>     more folders. I think you have 2 solutions :
>
>     1- You can copy all your .geom files for each different kind of
>     scanners in the CASTOR_CONFIG folder
>
>     2- Or creating a "castor_test" folder, where you write all your
>     .geom files (and the .geom files provided by CASToR) and set
>     CASTOR_CONFIG to the location of "castor_test" during the
>     installation.
>
>     Kind regards,
>     Didier
>
>     On 04/18/2017 04:36 PM, Michael Ljungberg wrote:
>
>         Sorry Didier
>
>         I meant the CASTOR_CONFIG folder. That was my question - if it
>         would be possible for your software to search first in the
>         local directory for a scanner name before looking in the
>         CASTOR_CONFIG folder. Sometimes one do simulations as function
>         of different camera geometries and I can then imagine I would
>         need one .geom file for each of them. If the search for the
>         scanner name is first made in the local directory and then in
>         the CASTOR_CONFIG folder then these local .geom files could be
>         isolated from the more permanent scanner system files, stored
>         in the CASTOR_CONFIG folder.
>
>         Hälsningar / Best regards
>
>         Michael
>
>         *From: *Didier Benoit <didier.benoit at inserm.fr>
>         <mailto:didier.benoit at inserm.fr>
>         *Date: *Tuesday, 18 April 2017 at 16:07
>         *To: *Michael Ljungberg <michael.ljungberg at med.lu.se>
>         <mailto:michael.ljungberg at med.lu.se>,
>         "castor-users at lists.castor-project.org"
>         <mailto:castor-users at lists.castor-project.org>
>         <castor-users at lists.castor-project.org>
>         <mailto:castor-users at lists.castor-project.org>
>         *Subject: *Re: [Castor-users] SPECT reading Interfile
>
>         With a time value set to 0, the SPECT reconstruction should work.
>
>         In your second question, what do you exactly mean by "SYSTEM
>         location" ? I'm not sure to understand. Is it your scanner
>         system location defined by "CASTOR_CONFIG" during the
>         compilation ? If it's the case you can't add a path in the Cdf
>         file for the tag " Scanner name". If you want to create a
>         custom scanner file you have to save it in the "CASTOR_CONFIG"
>         directory.
>
>         Kind Regards,
>         Didier
>
>
>
>         On 04/18/2017 03:26 PM, Michael Ljungberg wrote:
>
>             Dear Didier
>
>             Thank you for your explanation. I think it will not be a
>             major problem to implement. For SPECT reconstructions,
>             does the Time value be clearly defined?
>
>             Another related question regards the files for the system.
>             I wonder if it would be possible to allow castor-recon
>             program to first look in the local folder for a geometry
>             file before looking in the standard SYSTEM location? If I
>             implement direct writing to the caster format in the
>             simind program, I can foresee that the SYSTEM folder can
>             be quickly filled with files.  Alternatively, is it
>             possible to add a path to the system name in the cdh file?
>
>             Hälsningar / Best regards
>
>             Michael
>
>             *From: *Castor-users
>             <castor-users-bounces at lists.castor-project.org>
>             <mailto:castor-users-bounces at lists.castor-project.org> on
>             behalf of Didier Benoit <didier.benoit at inserm.fr>
>             <mailto:didier.benoit at inserm.fr>
>             *Date: *Tuesday, 18 April 2017 at 14:52
>             *To: *"castor-users at lists.castor-project.org"
>             <mailto:castor-users at lists.castor-project.org>
>             <castor-users at lists.castor-project.org>
>             <mailto:castor-users at lists.castor-project.org>
>             *Subject: *Re: [Castor-users] SPECT reading Interfile
>
>             Dear Michael,
>
>             Thanks for your interest. Interfile format is only used as
>             input/output format for image (not projection data). As
>             you have seen, input data for SPECT (and also for PET) is
>             composed of 2 files: a header file (*.Cdh) and a binary
>             file (*.Cdf) storing the data from a machine or a Monte
>             Carlo simulation. Here is some information about this Cdf
>             file. This file is not a pure histogram (a successive
>             number of counts by bin). The Data should (must) be
>             arrange as described in the “CASToR general documentation”
>             page 30.
>
>             For instance, in the case of a 64x64 float matrix for 64
>             angles (and I consider you don't have both normalization
>             and scatter informations), your Cdf file should contain
>             262 144 events (64x64x64) with the following format:
>
>             EVENT 0:
>             time: 0 (uint32_t)
>             data: 32 (float/double) it's your data for a specific bin
>             projection ID: 0 (uint32_t) it's the angle ID between 0
>             and 63 in this example
>             binID: 0 (uint32_t) it's the bin ID between 0 and (64x64 –
>             1) in this example
>
>             We don't provide a SPECT/PET data converter, but the
>             easiest way to create a correct Cdf file (I consider you
>             are using C/C++) is to create a struct like this:
>
>             struct SPECT_CASTOR_EVENT_FORMAT {
>                uint32_t     time;
>                float          data;
>                uint32_t    projectionID;
>                uint32_t    binID;
>             };
>
>             and store each bin from your data in the CASToR event format.
>
>             Kind Regards,
>             Didier Benoit
>
>
>
>             On 04/14/2017 05:34 PM, Michael Ljungberg wrote:
>
>                 Dear Castor developers
>
>                 I ran into this release a week ago and it is really a
>                 nice contribution you have made. I have been working
>                 with Monte Carlo simulations for many years developing
>                 the program simind and often I get this question of
>                 supplying reconstruction software since simind only
>                 produce projections. So being able to direct to your
>                 webpage would be natural.
>
>                 However, I dont understand how to read data into
>                 castor-recon. I also use Interfile and float values so
>                 when reading in the manual at you are using interfile
>                 for both input data and output gave me confidence for
>                 a smooth connection. But I dont see how to actual do
>                 this. I checked the spect benchmark file but the cdh
>                 format is different. So my question is how I can read
>                 in for example a 64x64 float matrices for 64 angles
>                 stored in a data file and with an associated interfile
>                 header file.
>
>                 Hälsningar / Best regards
>
>                 Michael Ljungberg
>
>                 Lund University
>
>                 Sweden
>
>
>
>
>
>
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>
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>
>
>
>
>             -- 
>
>             -------------------------------------------------------------------------------
>
>             Didier BENOIT, PhD,
>
>             Laboratoire de Traitement de l'Information Médicale (LaTIM - INSERM UMR 1101)
>
>             CHRU Morvan, bâtiment 1, étage 1
>
>             5 Avenue Foch
>
>             29609 Brest
>
>             FRANCE
>
>               
>
>             E-mail:
>
>             didier.benoit at univ-brest.fr
>             <mailto:didier.benoit at univ-brest.fr>
>
>             didier.benoit at inserm.fr <mailto:didier.benoit at inserm.fr>
>
>               
>
>             Tél: +33 (0)2 98 01 81 96
>
>             -------------------------------------------------------------------------------
>
>
>
>
>         -- 
>
>         -------------------------------------------------------------------------------
>
>         Didier BENOIT, PhD,
>
>         Laboratoire de Traitement de l'Information Médicale (LaTIM - INSERM UMR 1101)
>
>         CHRU Morvan, bâtiment 1, étage 1
>
>         5 Avenue Foch
>
>         29609 Brest
>
>         FRANCE
>
>           
>
>         E-mail:
>
>         didier.benoit at univ-brest.fr <mailto:didier.benoit at univ-brest.fr>
>
>         didier.benoit at inserm.fr <mailto:didier.benoit at inserm.fr>
>
>           
>
>         Tél: +33 (0)2 98 01 81 96
>
>         -------------------------------------------------------------------------------
>
>
>
>     -- 
>
>     -------------------------------------------------------------------------------
>
>     Didier BENOIT, PhD,
>
>     Laboratoire de Traitement de l'Information Médicale (LaTIM - INSERM UMR 1101)
>
>     CHRU Morvan, bâtiment 1, étage 1
>
>     5 Avenue Foch
>
>     29609 Brest
>
>     FRANCE
>
>     E-mail:
>
>     didier.benoit at univ-brest.fr <mailto:didier.benoit at univ-brest.fr>
>
>     didier.benoit at inserm.fr <mailto:didier.benoit at inserm.fr>
>
>     Tél: +33 (0)2 98 01 81 96
>
>     -------------------------------------------------------------------------------
>
>
>
>
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