Differences between revisions 4 and 18 (spanning 14 versions)

Name

mri_watershed - strips skull and other outer non-brain voxels from an acquired volume (usually T1).

Synopsis

mri_watershed [<options>] [input volume] [brain volume]

Positional Arguments

[input volume]
[output volume]

Required Flagged Arguments

None

Optional Flagged Arguments

-atlas	use the atlas information to correct the segmentation.	When the segmented brain is not correct, this option might help you.
-surf [surfname]	save the BEM surfaces.	In order to get the surfaces consistent with tkmedit, you have to use the option -useSRAS.
-useSRAS	use the surface RAS coordinates (not the scanner RAS) for surfaces.
-noT1	don't do T1 analysis. (Useful when running out of memory)
-less	shrink the surface
-more	expand the surface
-wat	use only the watershed algorithm
-T1	specify T1 input volume (T1 grey value = 110)
-wat+temp	watershed algo and first template smoothing
-first_temp	use only the first template smoothing + local matching
-surf_debug	visualize the surfaces onto the output volume
-brainsurf [surfname]	save the brain surface
-shk_br_surf [int_h surfname]	to save the brain surface shrank inward of int_h mm
-s [int_i int_j int_k]	add a seed point
-c [int_i int_j int_k]	specify the center of the brain (in voxel unit)
-r int_r	specify the radius of the brain (in voxel unit)
-t int_threshold	change the threshold in the watershed analyze process
-h int_hpf	precize the preflooding height (in percent)
-n	not use the watershed analyze process
-LABEL	labelize the output volume into scalp, skull, csf, gray and white
-man [int_csf int_trn int_gray]	to change the different parameters csf_max, transition_intensity and GM_intensity
-mask	mask a volume with the brain mask
--help	show usage message
--version	show the current version

Outputs

[brain volume]	skull stripped brain volume
[BEM surfaces]	when you specify the option -brainsurf surfname

Description

Produce the brain volume from T1 volume or the scanned volume.

Example 1

mri-watershed -atlas T1 brain

where T1 is the T1 volume and brain is the output brain volume. When the cerebellum is cut-off from the brain or getting the left/right asymmetric brain, you should first try this -atlas option.

Example 2

mri-watershed T1 brain

The same as the first example, but no correction is applied to the intermediate result.

Bugs

None

Links

FreeSurfer, FsFast

Methods Description

The "watershed" segmentation algorithm was used to dertermine the intensity values for white matter, grey matter, and CSF. 
A force field was then used to fit a spherical surface to the brain. The shape of the surface fit was then evaluated against a previously derived template. 

If you used -atlas option, then { The template was used to correct the surface. }

The finely grained sphere was fit to the brain.

(Segonne 2004)

References

["References/Segonne2004"]

Reporting Bugs

Report bugs to <freesurfer@nmr.mgh.harvard.edu>

Author/s

YasunariTosa

-  ⇤ ← Revision 4 as of 2004-08-03 21:51:16 → 
  Size: 857
  Editor: DavidTuch
  Comment: Modified for new Template.
+   ← Revision 18 as of 2004-08-23 12:05:40 → ⇥
  Size: 3875
  Editor: DavidTuch
  Comment: touched up formatting
-Deletions are marked like this.
+Additions are marked like this.
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-= mri_watershed =
+## Note: This page was created with the CommandTemplate
##
## If you're modifying this page please take a look at the
## latest version of CommandTemplate to ensure that you're
## using the latest version of the CommandTemplate
##
## See HelpOnCommandTemplate for description of formatting
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- mri_watershed - strip skull and other non-brain tissue voxels from a normalized T1 volume
+= Name =
mri_watershed - strips skull and other outer non-brain voxels from an acquired volume (usually T1).
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+Line 15:
- command argA argB -flag1 <arg1> -flag2 <arg2> -flag3 <arg3>
+mri_watershed  [<options>] [input volume] [brain volume]
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- argA

 Description

 argB 

 Description
+||[input volume]|| ||
||[output volume]|| ||
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+Line 22:
- -flag1 <arg1>

 Description

 - flag2 <arg2>

 Description
+None
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- -flag3 <arg3>

 Description.
+|| -atlas || use the atlas information to correct the segmentation.|| When the segmented brain is not correct, this option might help you. ||
|| -surf [surfname] || save the BEM surfaces.||  In order to get the surfaces consistent with tkmedit, you have to use the option -useSRAS.  ||
|| -useSRAS || use the surface RAS coordinates (not the scanner RAS) for surfaces. || ||
|| -noT1    || don't do T1 analysis.  (Useful when running out of memory) || ||
|| -less    || shrink the surface || ||
|| -more    || expand the surface || ||
|| -wat     || use only the watershed algorithm || ||
|| -T1      || specify T1 input volume (T1 grey value = 110) || ||
|| -wat+temp  || watershed algo and first template smoothing || ||
|| -first_temp || use only the first template smoothing + local matching || ||
|| -surf_debug || visualize the surfaces onto the output volume || ||
|| -brainsurf [surfname]  || save the brain surface || ||
|| -shk_br_surf [int_h surfname] || to save the brain surface shrank inward of int_h mm || ||
|| -s [int_i int_j int_k] || add a seed point || ||
|| -c [int_i int_j int_k] || specify the center of the brain (in voxel unit) || ||
|| -r int_r             || specify the radius of the brain (in voxel unit) || ||
|| -t int_threshold     || change the threshold in the watershed analyze process || ||
|| -h int_hpf           || precize the preflooding height (in percent) || ||
|| -n                   || not use the watershed analyze process || ||
|| -LABEL               || labelize the output volume into scalp, skull, csf, gray and white || ||
|| -man [int_csf int_trn int_gray] ||  to change the different parameters csf_max, transition_intensity and GM_intensity  || ||
|| -mask                || mask a volume with the brain mask || ||
|| --help               || show usage message || ||
|| --version            || show the current version || ||
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- file1
+|| [brain volume] || skull stripped brain volume ||
|| [BEM surfaces] || when you specify the option -brainsurf surfname ||
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- Description

 file2 

 Description
+= Description =
Produce the brain volume from T1 volume or the scanned volume.
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+Line 58:
- command argA argB -flag1 foo -flag2 goo
+mri-watershed -atlas T1 brain
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+Line 60:
- Description
+where T1 is the T1 volume and brain is the output brain volume.   
When the cerebellum is cut-off from the brain or getting the left/right asymmetric brain, you should first try this -atlas 
option.
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+Line 65:
- command argA argB -flag1 foo -flag2 goo -flag3 hoo
+mri-watershed T1 brain
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- Description
+The same as the first example, but no correction is applied to the intermediate result.
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-= Author =
 JaneSmith
+= Bugs =
None

= See Also =
["mri_normalize"]
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- CommandGuide
+FreeSurfer, FsFast
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- SkullStripping
+= Methods Description =
{{{

The "watershed" segmentation algorithm was used to dertermine the intensity values for white matter, grey matter, and CSF. 
A force field was then used to fit a spherical surface to the brain. The shape of the surface fit was then evaluated against a previously derived template. 

If you used -atlas option, then { The template was used to correct the surface. }

The finely grained sphere was fit to the brain.

(Segonne 2004) 
}}}
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- [wiki:Self:References#NameYear NameYear]
+["References/Segonne2004"]
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+Line 94:
-= Category =
 CategoryFreeSurferCommandSkullStripping
+= Reporting Bugs =
Report bugs to <freesurfer@nmr.mgh.harvard.edu>

= Author/s =
YasunariTosa