Re: [Freesurfer] white matter errors due to inhomogeneities (bright spots) in cortex

2016-09-05 Thread Ruyuan Zhang

Not sure it's helpful.

The simplest way I can think of is to directly edit WM.mgz. You can load 
wm.mgz into matlab, it's basically a 3D matrix. You can directly set 
values for wm matrix, for instance


wm(wm(:)>200)=110;

Then you save the new wm matrix into wm.mgz.



On 9/5/16 10:54 AM, Benjamin Baird wrote:

Hi Bruce and Clara,

Many thanks for your comments. Indeed the bright points are segmented 
as WM in wm.mgz, however these errors do not occur only in a few 
places but in many slices throughout the brain so manual edits will be 
very extensive, which is why we wanted to double check that there is 
no parameter tweak to recon that might at least help some of these 
errors. But sounds like there's no way to adjust the parameters of 
recon to mitigate this type of error? If not we will move forward with 
manual edits to wm.mgz as you suggest. Also I'm wondering if this is a 
common issue with GE scanners, as I've never encountered it before on 
Siemens, and I recently saw a post to the FS group from someone else 
encountering the same issue on GE


Best regards,
Ben

On Fri, Sep 2, 2016 at 8:36 AM, Clara Kühn <cku...@cbs.mpg.de 
<mailto:cku...@cbs.mpg.de>> wrote:


Hello Ben,

I am no expert, I can only talk from my experience.
I've had similar images in my data. Those might be blood vessels
or dura that were included in the surface. If they are included in
the surface on more than 5 slices and pretty well visible you
could delete those voxels from the brainmask. From the looks of
the attached screenshots however I wouldn't worry about the
brainmask but rather remove a few voxels from the wm.mgz. Then you
rerun the subject with the -wm flag and check again. If it is only
on one or two slices, though, I wouldn't edit it at all. The
surfaces are just not going to be perfect.

Hope I could help.
Clara


- Ursprüngliche Mail -
Von: "Benjamin Baird" <benjamin.s.ba...@gmail.com
<mailto:benjamin.s.ba...@gmail.com>>
An: freesurfer@nmr.mgh.harvard.edu
<mailto:freesurfer@nmr.mgh.harvard.edu>
Gesendet: Donnerstag, 1. September 2016 21:56:58
    Betreff: [Freesurfer] white matter errors due to inhomogeneities
(brightspots) in cortex

Dear Freesurfer experts,

We are currently working with some scans that were collected on a
GE 3T scanner. The goal is to analyze cortical thickness. The
scans seem to be relatively high quality with the exception that
there are what appear to be inhomogeneities in the intensity of
the gray matter (appears too bright in places), which is causing
the WM to extend/jump into cortex (see attached image). We're
wondering if there are any parameter adjustments to recon that
might help with this as the errors occur frequently enough that
fixing them all manually will be fairly cumbersome. This type of
error doesn’t seem to be discussed very much in the available
information on freesurfer quality control as far as we’ve seen.
Thanks in advance for any advice you might be able to offer.

Best regards,
Ben




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The information

Re: [Freesurfer] white matter errors due to inhomogeneities (bright spots) in cortex

2016-09-05 Thread Bruce Fischl

Hi Ben

sorry, but I don't know how to fix it automatically. You have voxels that 
look just like wm in the gm - that's going to be tough to avoid. You could 
try messing with some of the mris_make_surfaces options, but I don't have 
much confidence that it will help.


Any idea why you are getting the bright voxels in the first place?

Bruce


On Mon, 5 Sep 2016, Benjamin 
Baird wrote:



Hi Bruce and Clara,
Many thanks for your comments. Indeed the bright points are segmented as WM
in wm.mgz, however these errors do not occur only in a few places but in
many slices throughout the brain so manual edits will be very extensive,
which is why we wanted to double check that there is no parameter tweak to
recon that might at least help some of these errors. But sounds like there's
no way to adjust the parameters of recon to mitigate this type of error? If
not we will move forward with manual edits to wm.mgz as you suggest. Also
I'm wondering if this is a common issue with GE scanners, as I've never
encountered it before on Siemens, and I recently saw a post to the FS group
from someone else encountering the same issue on GE

Best regards,
Ben

On Fri, Sep 2, 2016 at 8:36 AM, Clara Kühn <cku...@cbs.mpg.de> wrote:
  Hello Ben,

  I am no expert, I can only talk from my experience.
  I've had similar images in my data. Those might be blood vessels
  or dura that were included in the surface. If they are included
  in the surface on more than 5 slices and pretty well visible you
  could delete those voxels from the brainmask. From the looks of
  the attached screenshots however I wouldn't worry about the
  brainmask but rather remove a few voxels from the wm.mgz. Then
  you rerun the subject with the -wm flag and check again. If it
  is only on one or two slices, though, I wouldn't edit it at all.
  The surfaces are just not going to be perfect.

  Hope I could help.
  Clara


  - Ursprüngliche Mail -
  Von: "Benjamin Baird" <benjamin.s.ba...@gmail.com>
  An: freesurfer@nmr.mgh.harvard.edu
  Gesendet: Donnerstag, 1. September 2016 21:56:58
  Betreff: [Freesurfer] white matter errors due to inhomogeneities
  (bright        spots) in cortex

  Dear Freesurfer experts,

  We are currently working with some scans that were collected on
  a GE 3T scanner. The goal is to analyze cortical thickness. The
  scans seem to be relatively high quality with the exception that
  there are what appear to be inhomogeneities in the intensity of
  the gray matter (appears too bright in places), which is causing
  the WM to extend/jump into cortex (see attached image). We're
  wondering if there are any parameter adjustments to recon that
  might help with this as the errors occur frequently enough that
  fixing them all manually will be fairly cumbersome. This type of
  error doesn’t seem to be discussed very much in the available
  information on freesurfer quality control as far as we’ve seen.
  Thanks in advance for any advice you might be able to offer.

  Best regards,
  Ben




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  to whom it is
  addressed. If you believe this e-mail was sent to you in error
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  Compliance HelpLine at
  http://www.partners.org/complianceline . If the e-mail was sent
  to you in error
  but does not contain patient information, please contact the
  sender and properly
  dispose of the e-mail.
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  dispose of the e-mail.



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Re: [Freesurfer] white matter errors due to inhomogeneities (bright spots) in cortex

2016-09-05 Thread Benjamin Baird
Hi Bruce and Clara,

Many thanks for your comments. Indeed the bright points are segmented as WM
in wm.mgz, however these errors do not occur only in a few places but in
many slices throughout the brain so manual edits will be very extensive,
which is why we wanted to double check that there is no parameter tweak to
recon that might at least help some of these errors. But sounds like
there's no way to adjust the parameters of recon to mitigate this type of
error? If not we will move forward with manual edits to wm.mgz as you
suggest. Also I'm wondering if this is a common issue with GE scanners, as
I've never encountered it before on Siemens, and I recently saw a post to
the FS group from someone else encountering the same issue on GE

Best regards,
Ben

On Fri, Sep 2, 2016 at 8:36 AM, Clara Kühn <cku...@cbs.mpg.de> wrote:

> Hello Ben,
>
> I am no expert, I can only talk from my experience.
> I've had similar images in my data. Those might be blood vessels or dura
> that were included in the surface. If they are included in the surface on
> more than 5 slices and pretty well visible you could delete those voxels
> from the brainmask. From the looks of the attached screenshots however I
> wouldn't worry about the brainmask but rather remove a few voxels from the
> wm.mgz. Then you rerun the subject with the -wm flag and check again. If it
> is only on one or two slices, though, I wouldn't edit it at all. The
> surfaces are just not going to be perfect.
>
> Hope I could help.
> Clara
>
>
> - Ursprüngliche Mail -
> Von: "Benjamin Baird" <benjamin.s.ba...@gmail.com>
> An: freesurfer@nmr.mgh.harvard.edu
> Gesendet: Donnerstag, 1. September 2016 21:56:58
> Betreff: [Freesurfer] white matter errors due to inhomogeneities (bright
>   spots) in cortex
>
> Dear Freesurfer experts,
>
> We are currently working with some scans that were collected on a GE 3T
> scanner. The goal is to analyze cortical thickness. The scans seem to be
> relatively high quality with the exception that there are what appear to be
> inhomogeneities in the intensity of the gray matter (appears too bright in
> places), which is causing the WM to extend/jump into cortex (see attached
> image). We're wondering if there are any parameter adjustments to recon
> that might help with this as the errors occur frequently enough that fixing
> them all manually will be fairly cumbersome. This type of error doesn’t
> seem to be discussed very much in the available information on freesurfer
> quality control as far as we’ve seen.
> Thanks in advance for any advice you might be able to offer.
>
> Best regards,
> Ben
>
>
>
>
> ___
> Freesurfer mailing list
> Freesurfer@nmr.mgh.harvard.edu
> https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
>
>
> The information in this e-mail is intended only for the person to whom it
> is
> addressed. If you believe this e-mail was sent to you in error and the
> e-mail
> contains patient information, please contact the Partners Compliance
> HelpLine at
> http://www.partners.org/complianceline . If the e-mail was sent to you in
> error
> but does not contain patient information, please contact the sender and
> properly
> dispose of the e-mail.
> ___
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>
> The information in this e-mail is intended only for the person to whom it
> is
> addressed. If you believe this e-mail was sent to you in error and the
> e-mail
> contains patient information, please contact the Partners Compliance
> HelpLine at
> http://www.partners.org/complianceline . If the e-mail was sent to you in
> error
> but does not contain patient information, please contact the sender and
> properly
> dispose of the e-mail.
>
>
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Re: [Freesurfer] white matter errors due to inhomogeneities (bright spots) in cortex

2016-09-02 Thread Benjamin Baird
Hi Bruce and Clara,

Thanks for your comments. Indeed the bright points are segmented as WM in
wm.mgz, however these errors do not occur only in a few places but in many
slices throughout the brain so manual edits will be quite extensive, which
is why we wanted to double check that there is no parameter tweak to recon
that might at least help some of these errors. But sounds like there's no
way to adjust the parameters of recon to mitigate this type of error? If
not we will move forward with manual edits to wm.mgz as you suggest. Thanks!

Best regards,
Ben

On Fri, Sep 2, 2016 at 8:36 AM, Clara Kühn <cku...@cbs.mpg.de> wrote:

> Hello Ben,
>
> I am no expert, I can only talk from my experience.
> I've had similar images in my data. Those might be blood vessels or dura
> that were included in the surface. If they are included in the surface on
> more than 5 slices and pretty well visible you could delete those voxels
> from the brainmask. From the looks of the attached screenshots however I
> wouldn't worry about the brainmask but rather remove a few voxels from the
> wm.mgz. Then you rerun the subject with the -wm flag and check again. If it
> is only on one or two slices, though, I wouldn't edit it at all. The
> surfaces are just not going to be perfect.
>
> Hope I could help.
> Clara
>
>
> - Ursprüngliche Mail -
> Von: "Benjamin Baird" <benjamin.s.ba...@gmail.com>
> An: freesurfer@nmr.mgh.harvard.edu
> Gesendet: Donnerstag, 1. September 2016 21:56:58
> Betreff: [Freesurfer] white matter errors due to inhomogeneities (bright
>   spots) in cortex
>
> Dear Freesurfer experts,
>
> We are currently working with some scans that were collected on a GE 3T
> scanner. The goal is to analyze cortical thickness. The scans seem to be
> relatively high quality with the exception that there are what appear to be
> inhomogeneities in the intensity of the gray matter (appears too bright in
> places), which is causing the WM to extend/jump into cortex (see attached
> image). We're wondering if there are any parameter adjustments to recon
> that might help with this as the errors occur frequently enough that fixing
> them all manually will be fairly cumbersome. This type of error doesn’t
> seem to be discussed very much in the available information on freesurfer
> quality control as far as we’ve seen.
> Thanks in advance for any advice you might be able to offer.
>
> Best regards,
> Ben
>
>
>
>
> ___
> Freesurfer mailing list
> Freesurfer@nmr.mgh.harvard.edu
> https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
>
>
> The information in this e-mail is intended only for the person to whom it
> is
> addressed. If you believe this e-mail was sent to you in error and the
> e-mail
> contains patient information, please contact the Partners Compliance
> HelpLine at
> http://www.partners.org/complianceline . If the e-mail was sent to you in
> error
> but does not contain patient information, please contact the sender and
> properly
> dispose of the e-mail.
> ___
> Freesurfer mailing list
> Freesurfer@nmr.mgh.harvard.edu
> https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
>
>
> The information in this e-mail is intended only for the person to whom it
> is
> addressed. If you believe this e-mail was sent to you in error and the
> e-mail
> contains patient information, please contact the Partners Compliance
> HelpLine at
> http://www.partners.org/complianceline . If the e-mail was sent to you in
> error
> but does not contain patient information, please contact the sender and
> properly
> dispose of the e-mail.
>
>
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Re: [Freesurfer] white matter errors due to inhomogeneities (bright spots) in cortex

2016-09-02 Thread Clara Kühn
Hello Ben,

I am no expert, I can only talk from my experience. 
I've had similar images in my data. Those might be blood vessels or dura that 
were included in the surface. If they are included in the surface on more than 
5 slices and pretty well visible you could delete those voxels from the 
brainmask. From the looks of the attached screenshots however I wouldn't worry 
about the brainmask but rather remove a few voxels from the wm.mgz. Then you 
rerun the subject with the -wm flag and check again. If it is only on one or 
two slices, though, I wouldn't edit it at all. The surfaces are just not going 
to be perfect.

Hope I could help.
Clara


- Ursprüngliche Mail -
Von: "Benjamin Baird" <benjamin.s.ba...@gmail.com>
An: freesurfer@nmr.mgh.harvard.edu
Gesendet: Donnerstag, 1. September 2016 21:56:58
Betreff: [Freesurfer] white matter errors due to inhomogeneities (bright    
spots) in cortex

Dear Freesurfer experts, 

We are currently working with some scans that were collected on a GE 3T 
scanner. The goal is to analyze cortical thickness. The scans seem to be 
relatively high quality with the exception that there are what appear to be 
inhomogeneities in the intensity of the gray matter (appears too bright in 
places), which is causing the WM to extend/jump into cortex (see attached 
image). We're wondering if there are any parameter adjustments to recon that 
might help with this as the errors occur frequently enough that fixing them all 
manually will be fairly cumbersome. This type of error doesn’t seem to be 
discussed very much in the available information on freesurfer quality control 
as far as we’ve seen. 
Thanks in advance for any advice you might be able to offer. 

Best regards, 
Ben 




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Re: [Freesurfer] white matter errors due to inhomogeneities (bright spots) in cortex

2016-09-01 Thread Bruce Fischl

Hi Ben

are the bright points segmented as wm in the wm.mgz? If so, you might try 
erasing them and rerunning


cheers
Bruce
On Wed, 31 Aug 2016, Benjamin Baird wrote:


Dear Freesurfer experts,

We are currently working with some scans that were collected on a GE 3T
scanner. The goal is to analyze cortical thickness. The scans seem to be
relatively high quality with the exception that there are what appear to be
inhomogeneities in the intensity of the gray matter (appears too bright in
places), which is causing the WM to extend/jump into cortex (see attached
image). We're wondering if there are any parameter adjustments to recon that
might help with this as the errors occur frequently enough that fixing them
all manually will be fairly cumbersome. This type of error doesn’t seem to
be discussed very much in the available information on freesurfer quality
control as far as we’ve seen. Thanks in advance for any thoughts
recommendations or advice you might be able to offer.

Best regards,
Ben

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contains patient information, please contact the Partners Compliance HelpLine at
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