[Castor-users] PSF+TOF reconstruction error

[Hadi Rezaei]

Hi marina and other castor users
Should I change or add TOF information in .cdh file manually to see the
effect of TOF variations?
As I mentioned in the previous emails when I use  "-TOF reso" command on
castor-GATERootToCastor I see the warning:" quantization TOF bin size wrong
or not provided, so switching to TOF list-mode reconstruction which
neglects the quantization TOF bin size!" on the reconstruction process. In
previous email I sent two of the content of the .cdh files.
Thank you so much for your help
Best
Hadi


On Tue, Sep 15, 2020 at 8:27 PM Hadi Rezaei <hrezaei.m.ph at gmail.com> wrote:

> I use castor_v3.0.1. Two of the content of my .cdh files are below:
> 1)
> Data filename: miniderenzo420ring0.6sTOF_df.Cdf
> Number of events: 46858725
> Data mode: list-mode
> Data type: PET
> Start time (s): 0
> Duration (s): 0.6
> Scanner name: miniderenzo420ring0.6sTOF
> Calibration factor: 1
> Isotope: unknown
> TOF information flag: 1
> TOF resolution (ps): 430
> List TOF measurement range (ps): 5753.19
> Coincidence kind flag: 1
> Maximum axial difference mm: 1200
>
> 2)
> Data filename: miniderenzo336ring0.6sTOF350_df.Cdf
> Number of events: 42513982
> Data mode: list-mode
> Data type: PET
> Start time (s): 0
> Duration (s): 0.6
> Scanner name: miniderenzo336ring0.6sTOF350
> Calibration factor: 1
> Isotope: unknown
> TOF information flag: 1
> TOF resolution (ps): 350
> List TOF measurement range (ps): 4800
> Coincidence kind flag: 1
> Maximum axial difference mm: 960
> ***********************************************
> The TOF values are 430 ps and 350 ps that I added on "-TOF reso" on
> cstor-GATERootToCastor. I only added "Maximum axial difference" on .cdh
> files.
> thank you so much
> Best
>
> On Tue, Sep 15, 2020 at 7:21 PM FILIPOVIC PIERUCCI Marina <
> Marina.FILIPOVICPIERUCCI at cea.fr> wrote:
>
>> Strange, which version of CASToR do you use? What is the size of the list
>> mode TOF quantization bin and what do you mean by different TOF values,
>> different values of the TOF quantization bin size? Do you add this info in
>> the .cdh yourself or do you rely on the GATE to CASToR converter?
>> ------------------------------
>> *De :* Hadi Rezaei [hrezaei.m.ph at gmail.com]
>> *Envoyé :* mardi 15 septembre 2020 16:29
>> *À :* FILIPOVIC PIERUCCI Marina
>> *Cc :* castor-users at lists.castor-project.org
>> *Objet :* Re: [Castor-users] PSF+TOF reconstruction error
>>
>> Hi Marina
>> Thank you for responding
>> My reconstructed image is Ok and when I imply only TOF (not PSF) I don't
>> see this warning and the TOF bin is provided in .cdh file however the
>> different TOF values don't make a difference in image quality. Is this an
>> issue in the reconstruction process or it is normal?
>> Thank you
>> Best
>> Hai
>>
>> On Tue, Sep 15, 2020 at 2:46 PM FILIPOVIC PIERUCCI Marina <
>> Marina.FILIPOVICPIERUCCI at cea.fr> wrote:
>>
>>> Hi Hadi,
>>>
>>> This warning should be related only to TOF, not to the use of PSF. It
>>> says that your input datafile implies that your scanner has an (almost)
>>> infinite precision for TOF measurements. If this is the case everything's
>>> ok, otherwise if your scanner quantizes TOF measurements, you should
>>> provide the quantization bin or step it in the datafile header (.cdh).
>>>
>>> All of this won't really make a difference for the reconstructed image,
>>> unless the quantization of the TOF measurements is very rough, which is
>>> probably not the case for your scanner.
>>>
>>> Is the reconstructed image OK?
>>>
>>> Best
>>>
>>> Marina
>>>
>>> ------------------------------
>>> *De :* Castor-users [castor-users-bounces at lists.castor-project.org] de
>>> la part de Hadi Rezaei [hrezaei.m.ph at gmail.com]
>>> *Envoyé :* mardi 15 septembre 2020 12:05
>>> *À :* castor-users at lists.castor-project.org
>>> *Objet :* [Castor-users] PSF+TOF reconstruction error
>>>
>>> Dear CASToR users
>>> I used TOF + psf for reconstruction a Derenzo phantom but I found this
>>> warning.
>>> *"Warning: quantization TOF bin size wrong or not provided, so switching
>>> to TOF list-mode reconstruction which neglects the quantization TOF bin
>>> size!"*
>>> Does it mean that I can not use psf and TOF together in CASTOR??  I need
>>> to investigate PSF+TOF. How can I do it??
>>> Any help would be appreciated.
>>> Best
>>> Hadi
>>>
>>
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