[MINC-users] get_meansd_voi --- problems with PET volumes

[EJ Nikelski]

Thanks Alex,

    Yup, I really should have that 3rd cup of coffee before posting
anything. Thanks again.


-Jim




Alex ZIJDENBOS wrote:
> Judging by your volume's start values, I would say that your PET
> volume is not in Talairach space at all, and the Talairach (world)
> coordinate 0,0,0 is most likely well outside your volume... You should
> register/resample to stx space first.
> 
> -- Alex
> 
> On Wed, Mar 15, 2006 at 01:45:16PM -0500, EJ Nikelski wrote:
> 
>>Hi,
>>
>>   I'm trying to extract VOI mean and sd using get_meansd_voi. When I
>>try it using ...
>>
>>
>>>get_meansd_voi pet.mnc 0 0 0 1 0
>>
>>... which should get me the value at Talairach (0,0,0), instead, I get
>>
>>
>>>n/a n/a 0
>>
>>   Interestingly, if I try to use a larger roi radius, I get ...
>>
>>[~] 83 >get_meansd_voi pet.mnc 0 0 0 1 3
>>ncvarget: ncid 3: Index exceeds dimension bound
>>miicv_get: MINC package entry point
>>ncvarget: ncid 3: Index exceeds dimension bound
>>miicv_get: MINC package entry point
>>0.000 0.000 3
>>
>>   Now, if I try this with the average 305 MRI T1, I get no problems.
>>Perhaps the problem is related to the volume data type? The PET volume
>>I'm using is the usual ...
>>
>>[~] 84 >mincinfo pet.mnc
>>file: pet.mnc
>>image: signed__ short -32000 to 32000
>>image dimensions: zspace yspace xspace
>>    dimension name         length         step        start
>>    --------------         ------         ----        -----
>>    zspace                     63       -2.425      -427.96
>>    yspace                    128        2.025     -128.588
>>    xspace                    128        2.025     -128.588
>>
>>
>>   Now, I'm certain this has worked before ... and on the same PET
>>volumes. What am I missing?
>>
>>
>>Thanks,
>>
>>-Jim
>>
>>
>>-- 
>>E. James Nikelski, Ph.D.
>>Postdoctoral Research Fellow
>>Bloomfield Centre for Research in Aging
>>Lady Davis Institute for Medical Research
>>Sir Mortimer B. Davis - Jewish General Hospital
>>McGill University
>>Tel: (514) 340-8222 x 2298
>>Fax: (514) 340-8295
>>_______________________________________________
>>MINC-users at bic.mni.mcgill.ca
>>http://www.bic.mni.mcgill.ca/mailman/listinfo/minc-users
> 
> 
> 
>