[Mristudio-users] DTI gradient table

Fri Jan 27 16:27:04 EST 2012

Hi Hangji,
               I figured out that it was Philips 3T scanner (but we still
don't know what kind, though it is out of state scanner images we got), and
it has 25 gradient directions (including the bo image). I used the
following gradient table:

0: 0, 0, 0

1: 0.532212965784, 0.104012540712, -0.840196852187

2: 0.250139840140, -0.721834058886, 0.645279514479

3: -0.633506688611, -0.753135632571, -0.177358378534

4: -0.218922463231, 0.850392517067, 0.478440719431

5: -0.413149806364, -0.780294228218, 0.469519067675

6: 0.734236034340, -0.661803691272, 0.151371463942

7: 0.936469940841, 0.054189066241, 0.346536570943

8: -0.333112408327, -0.242859001882, 0.911073887576

9: 0.103315488089, -0.991677012629, -0.076828461807

10: -0.926539655526, 0.372983070696, -0.049070313963

11: 0.801488967040, 0.543143312217, -0.250221458126

12: -0.916836769339, -0.261947685782, 0.301320009791

13: -0.537755795155, 0.438027927278, -0.720382009562

14: -0.213559057919, -0.664684481487, -0.715951862105

15: -0.124138610474, -0.051815651202, -0.990911067493

16: 0.273979937314, 0.960273112918, -0.053014550417

17: -0.443315490443, 0.878048334487, -0.180284492503

18: 0.024170841904, 0.368771526312, 0.929205753202

19: 0.568365159741, 0.637098308775, 0.520640749604

20: 0.930930389545, -0.168157726945, -0.324178328533

21: -0.825458835938, -0.182178469442, -0.534255290516

22: 0.472597880311, -0.629557481175, -0.616691674520

23: 0.504263360030, -0.129264527496, 0.853820323992

24: 0.149335563174, 0.688742589708, -0.709459325610

25: -0.694717409994, 0.344411933027, 0.631465074759
 But unfortunately, the image quality looks very bad for the color map
images...
I'll appreciate your reply.

Thanks
Supreet.

On Fri, Jan 27, 2012 at 2:22 PM, Hangyi Jiang <hjiang at jhmi.edu> wrote:

> hi,Supreet
>
>  seems that your dataset has not being loaded in correctly,  or they are
> not in Siemens Mosaic format.
>
> you said that the dataset has " 25 gradient directions", right?  if so,
> you will get 25 image volumes (and maybe more,  since B0 images) after
> "File->Dti Mapping -> Siemens Mosaic...".  please double check if the
> images are loaded in correctly before you figure out the gradient table.
>
> regards,
>
> hangyi
>
>
>
>
>
> ________________________________________
> From: Supreet kaur [ksupreet6 at gmail.com]
> Sent: Friday, January 27, 2012 1:31 PM
> To: Hangyi Jiang
> Subject: Re: DTI gradient table
>
> Hi Hangyi,
>                        When I do the steps as you suggested , it gives a
> the following: I don't know what to do at this point, Please help
>
> 0: 0.000000, 0.000000, 0.000000, 1703965
> 1: 0.000000, 0.000000, 0.000000, 524297
> 2: 0.000000, 0.000000, 0.000000, 1507345
> 3: 0.000000, 0.000000, 0.000000, 851980
> 4: 0, 0, 0, 0
> 5: 0, 0, 0, 0
> 6: 0, 0, 0, 0
> 7: 0, 0, 0, 0
> 8: 0, 0, 0, 0
> 9: 0, 0, 0, 0
> 10: 0, 0, 0, 0
> 11: 0, 0, 0, 0
> 12: 0, 0, 0, 0
> 13: 0, 0, 0, 0
> 14: 0, 0, 0, 0
> 15: 0, 0, 0, 0
> 16: 0, 0, 0, 0
> 17: 0, 0, 0, 0
> 18: 0, 0, 0, 0
> 19: 0, 0, 0, 0
> 20: 0, 0, 0, 0
> 21: 0, 0, 0, 0
> 22: 0, 0, 0, 0
> 23: 0, 0, 0, 0
> 24: 0, 0, 0, 0
> 25: 0, 0, 0, 0
> 26: 0, 0, 0, 0
> 27: 0, 0, 0, 0
> 28: 0, 0, 0, 0
> 29: 0, 0, 0, 0
> 30: 0, 0, 0, 0
> 31: 0, 0, 0, 0
> 32: 0, 0, 0, 0
> 33: 0, 0, 0, 0
> 34: 0, 0, 0, 0
> 35: 0, 0, 0, 0
> 36: 0, 0, 0, 0
> 37: 0, 0, 0, 0
> 38: 0, 0, 0, 0
> 39: 0, 0, 0, 0
> 40: 0, 0, 0, 0
> 41: 0, 0, 0, 0
> 42: 0, 0, 0, 0
> 43: 0, 0, 0, 0
> 44: 0, 0, 0, 0
> 45: 0, 0, 0, 0
> 46: 0, 0, 0, 0
> 47: 0, 0, 0, 0
> 48: 0, 0, 0, 0
> 49: 0, 0, 0, 0
> 50: 0, 0, 0, 0
> 51: 0, 0, 0, 0
> 52: 0, 0, 0, 0
> 53: 0, 0, 0, 0
> 54: 0, 0, 0, 0
> 55: 0, 0, 0, 0
> 56: 0, 0, 0, 0
> 57: 0, 0, 0, 0
> 58: 0, 0, 0, 0
> 59: 0, 0, 0, 0
> 60: 0, 0, 0, 0
> 61: 0, 0, 0, 0
> 62: 0, 0, 0, 0
> 63: 0, 0, 0, 0
>
> On Fri, Jan 27, 2012 at 1:11 PM, Hangyi Jiang <hjiang at jhmi.edu<mailto:
> hjiang at jhmi.edu>> wrote:
>
> if the dataset is saved as Siemens Mosaic format, you can try to get the
> gradients from file header.
> try this:  File->DtiMapping -> Siemens Mosaic ->.. specify the file name
> (actually folder name).. clicking "get gradients from file header"
> button....;
>
> let me know if you have any problems..
>
> hangyi
>
> hangyi
>
>
>
>
>
>
> ________________________________________
> From: Supreet kaur [ksupreet6 at gmail.com<mailto:ksupreet6 at gmail.com>]
> Sent: Friday, January 27, 2012 12:15 PM
> To: DTI Studio, ROI Editor, DiffeoMap Questions/Support
> Cc: Hangyi Jiang; Susumu Mori
> Subject: DTI gradient table
>
> Dear DTI experts,
>                            I have a DTI data with 25 gradient directions,
> what gradient table should we use for that?
> Its a Siemens 3T scanner...
> I'll appreciate your help.
>
> Thanks
>
> Sincerely,
>
> Supreet kaur,
> Biomedical research engineer,
> Nationwide Childrens Hospital,
> Columbus, OH
> (614)355-3509<tel:%28614%29355-3509>
>
>
>
>
> --
> Sincerely,
>
> Supreet kaur,
> Biomedical research engineer,
> Nationwide Childrens Hospital,
> Columbus, OH
> (614)355-3509
>
>

-- 
Sincerely,

Supreet kaur,
Biomedical research engineer,
Nationwide Childrens Hospital,
Columbus, OH
(614)355-3509
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