[Vv] Issue with PET images

[Thomas BAUDIER]

Hello Elia,

My feeling is the image is converted to short integer. I suppose you use 
clitkImageConvert to convert dicom to mha, could you try with the option 
-t ushort please ?
The black area you can see are the values >= 32767 (the short max).

Thomas

On 07/09/2021 16:30, Lombardo, Elia wrote:
>
> Dear vv team,
>
> Me and my colleagues are using vv to preprocess PET Dicom images for a 
> project.
>
> When opening some of the Dicom images in vv we see many  ‘black 
> islands’, i.e. areas with large negative values (top row in the image 
> below). We then turn the negative values to positive values for the 
> island areas, convert dicom to mha and get a reasonably well looking 
> image (bottom row).
>
> However, we checked the exact data value in a few points of interest 
> and compared it with the PET values displayed when opening the 
> original dicom in a Raystation TPS and saw some discrepancies (e.g. in 
> Raystation we get a value of 34000 while in the corrected mha opened 
> in vv we have 31000).
>
> Is this issue known?
>
> Thanks in advance for your help!
>
> Best,
>
> *Elia Lombardo, M.Sc.*
>
> *Medizinische Physik / Medical Physics*
>
> LMU Klinikum
>
> Klinik und Poliklinik für Strahlentherapie und Radioonkologie
>
> Campus Großhadern  | Marchioninistraße 15  | 81377 München
>
> Tel. 089 4400-73757
>
> Elia.Lombardo at med.uni-muenchen.de 
> <mailto:Elia.Lombardo at med.uni-muenchen.de>| 
> _www.lmu-klinikum.de/strahlentherapie-und-radioonkologie 
> <http://www.lmu-klinikum.de/strahlentherapie-und-radioonkologie>_
>
> Das Klinikum der Universität München ist eine Anstalt des öffentlichen 
> Rechts (AöR)
>
> PS:
> Bitte denken Sie an die Umwelt bevor Sie diese E-Mail drucken!
> Please consider the environment before printing this email!
>
>
> _______________________________________________
> vv mailing list
> vv at creatis.insa-lyon.fr
> https://www.creatis.insa-lyon.fr/mailman/listinfo/vv

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.creatis.insa-lyon.fr/pipermail/vv/attachments/20210907/74af4e4d/attachment-0001.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image003.jpg
Type: image/jpeg
Size: 658559 bytes
Desc: not available
URL: <http://www.creatis.insa-lyon.fr/pipermail/vv/attachments/20210907/74af4e4d/attachment-0001.jpg>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image001.png
Type: image/png
Size: 3420 bytes
Desc: not available
URL: <http://www.creatis.insa-lyon.fr/pipermail/vv/attachments/20210907/74af4e4d/attachment-0002.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image002.png
Type: image/png
Size: 20259 bytes
Desc: not available
URL: <http://www.creatis.insa-lyon.fr/pipermail/vv/attachments/20210907/74af4e4d/attachment-0003.png>