[gate-users] Image Reconstruction of Gate output

Mutanga Theodore muathe02 at student.umu.se
Mon Jan 3 18:43:49 CET 2005


Hello there,
thanks very much, I was working on your code again today using the tip
from Kris, I still got the segmetation fault
well its best I wait for you to test it. I look forward to hearing from
you tomorrow.
Thanks for the information about the data for comparison. I already had
that one, I was looking for any articles with ECAT exact hr+ using NEMA
2001 maybe someone knows something ... ?

regards

Theodore

> Dear Theodore and Long,
>
> Yes I'm back, and sorry for taking me time replying to your emails.
> Long, I think what you have suggested in your previous email regarding
> evaluating the sinogram binner for the DST, and try to incorporate it
> with GATE, is a great idea. Meanwhile, I am also testing that for the
> DST configuration. Hopefully I will get back to you tomorrow with my
> feedback.
>
> Theodore, for your NEMA measurements, I know O. Mawlawi at M.D. Anderson
> did the NEMA2001 measurements for the DST. It was published in the JNM
> (J Nucl Med. 2004 Oct;45(10):1734-42); you may wana refer to that, and
> reproduce their analysis method, for comparison.
>
>
> 	Cheers,
>
> 	Sadek
>
>
>
> -----Original Message-----
> From: gate-users-bounces at lphe1pet1.epfl.ch
> [mailto:gate-users-bounces at lphe1pet1.epfl.ch] On Behalf Of Mutanga
> Theodore
> Sent: Monday, January 03, 2005 11:30 AM
> To: Long ZHANG; GATE feedback and helpline for Users
> Subject: Re:RE: [gate-users] Image Reconstruction of Gate output
>
> Hi Long,
> it seems Sadek is back, have you written to him about the code ?
>
> Cheers
>
> Theodore
>
> By the way I was simulating the ECAT exact hr+ and I would like to
> compare my results with someone Here is what I had for the resolution
> measurements , NEMA 2001 !
>
> transverse @ 1cm = 8.3 mm
> axial @1 cm 11.5 mm
>
>
> transverse radial @ 10cm = 10.59mm
> transverse tangential@ 10cm = 10.66mm
>
> axial @10cm 10.31 mm
>
>
> I wish to find out from the GATE users if these look reasonable, I was
> planning to do measurements myself on the ecat but I dont have acceess
> to one since initially I was simulating the DST. Also in the NEMA 2001
> there is no mention about matrix size for reconstruction , doesnt this
> affect the resolution ? I did not correct for anythin in the data from
> GATE , would it be better to correct for randoms, scatter ect , if so
> HOW (using GATE ?)?
>
>
> Cheers
>
> 'Theo
>
>> Dear Kris,
>>
>> Thank you very much.
>>
>> It seems that I have mistake the sinogram width (angle position) as
>> sinogram length (view number, or tangential bin number, or
>> displacement position).
>> Am I
>> right now?
>>
>> Regards,
>>
>> Long
>>
>> In your mail:
>>>From:"Kris Thielemans" <kris.thielemans at csc.mrc.ac.uk>
>>>Reply-To: GATE feedback and helpline for Users
>>><gate-users at lphe1pet1.epfl.ch>
>>>To: "'Long ZHANG'" <zhanglong99 at tsinghua.org.cn>,
>>   "'GATE feedback and helplinefor Users'"
>> <gate-users at lphe1pet1.epfl.ch>
>>>Subject: RE: [gate-users] Image Reconstruction of Gate output
>>>
>>>>
>>>> BTW, I was pussled by the sinogram width of DST (420 crystal per
>>>> ring). The number 249 is larger than the 420/2 = 210. How can DST
>>>> get the extra LORs of 39? By interpolation? Could this help to
>>>> improve the spatial resolution? Thank you!
>>>>
>>>Notation: N= num_detectors per ring
>>>
>>>Why do you think that the max sinogram width is N /2? This is a
>>>hardware choice (recent CTI scanners tend to have sinogram_width=N/2).
>
>>>The 'physical' maximum of LORs in 2D sinograms is (N^2-N)/2 (i.e. all
>>>lines between pairs of detectors, excluding the degenerate cases, and
>>>identifying det pairs ij and ji). The max number of views is N/2
>>>(you'd expect N, but it's halved because of interleaving). So, the max
>
>>>sinogram width is something like (N-1)
>>>
>>>
>>>Kris
>>>
>>>_______________________________________________
>>>gate-users mailing list
>>>gate-users at lphe1pet1.epfl.ch
>>>http://lphe1pet1.epfl.ch/mailman/listinfo/gate-users
>>>
>>
>>
>> _______________________________________________
>> gate-users mailing list
>> gate-users at lphe1pet1.epfl.ch
>> http://lphe1pet1.epfl.ch/mailman/listinfo/gate-users
>>
>
> _______________________________________________
> gate-users mailing list
> gate-users at lphe1pet1.epfl.ch
> http://lphe1pet1.epfl.ch/mailman/listinfo/gate-users
>
>
>
>
>
>      =====================================================================
>
>      Please note that this e-mail and any files transmitted with it may be
>      privileged, confidential, and protected from disclosure under
>      applicable law. If the reader of this message is not the intended
>      recipient, or an employee or agent responsible for delivering this
>      message to the intended recipient, you are hereby notified that any
>      reading, dissemination, distribution, copying, or other use of this
>      communication or any of its attachments is strictly prohibited.  If
>      you have received this communication in error, please notify the
>      sender immediately by replying to this message and deleting this
>      message, any attachments, and all copies and backups from your
>      computer.
>
>
> _______________________________________________
> gate-users mailing list
> gate-users at lphe1pet1.epfl.ch
> http://lphe1pet1.epfl.ch/mailman/listinfo/gate-users
>



More information about the Gate-users mailing list