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iage analysis through intensity-time plots
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| I have a series of 60 images (from DSC-MRI) that I need to analyze in
order to detect the region of a tumor tissue. I need to perform a
pixel by pixel analysis to get the time at which the signal is
minimum (signal drops due to arrival of contrast agent).
Here is the loop in I tried to use to get the time at minimum signal
intensity,where MF is a 3D array with the 60 (128x128)images
for i=1:128
for ii=1:128
MinS(i,ii)=(min(MF(i,ii,1:60)));
end
end
I need to map the minimum signal intensity with respect to the the
time at minimum intensity. It is expected that the time values be
around image #20, (19,20,21, within that range). I also need to
compute the full width at half minimum for each pixel and map that.
If anyone has any hints for me, please do share!
Thanks,
Dina
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| Peter Boettcher 2005-11-23, 7:05 pm |
| Dee <dandoun@uab.edu> writes:
> I have a series of 60 images (from DSC-MRI) that I need to analyze in
> order to detect the region of a tumor tissue. I need to perform a
> pixel by pixel analysis to get the time at which the signal is
> minimum (signal drops due to arrival of contrast agent).
> Here is the loop in I tried to use to get the time at minimum signal
> intensity,where MF is a 3D array with the 60 (128x128)images
>
> for i=1:128
> for ii=1:128
> MinS(i,ii)=(min(MF(i,ii,1:60)));
> end
> end
>
> I need to map the minimum signal intensity with respect to the the
> time at minimum intensity. It is expected that the time values be
> around image #20, (19,20,21, within that range). I also need to
> compute the full width at half minimum for each pixel and map that.
> If anyone has any hints for me, please do share!
You should be able to run:
[minv mins] = min(MF, 3);
That is, minimum along the 3rd dimension, and return both the minimum
value, and the index at which the minimum occurs.
--
Peter Boettcher <boettcher@ll.mit.edu>
MIT Lincoln Laboratory
MATLAB FAQ: http://www.mit.edu/~pwb/cssm/
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| Peter Boettcher wrote:
>
>
> Dee <dandoun@uab.edu> writes:
>
> analyze in
a[color=darkred]
> signal
> the
be[color=darkred]
>
>
> You should be able to run:
>
> [minv mins] = min(MF, 3);
>
> That is, minimum along the 3rd dimension, and return both the
> minimum
> value, and the index at which the minimum occurs.
>
>
> --
> Peter Boettcher <boettcher@ll.mit.edu>
> MIT Lincoln Laboratory
> MATLAB FAQ: <http://www.mit.edu/~pwb/cssm/>
>
I just tried that and I got this error message,
Error using ==> min
MIN with two matrices to compare and two output arguments is not
supported.
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| Peter Boettcher 2005-11-29, 7:07 pm |
| dee <dandoun@uab.edu> writes:
> Peter Boettcher wrote:
> I just tried that and I got this error message,
> Error using ==> min
> MIN with two matrices to compare and two output arguments is not
> supported.
Oops. I missed the middle argument.
You could always try "help min", which would say:
[Y,I] = MIN(X,[],DIM) operates along the dimension DIM.
That's what I meant.
--
Peter Boettcher <boettcher@ll.mit.edu>
MIT Lincoln Laboratory
MATLAB FAQ: http://www.mit.edu/~pwb/cssm/
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