From zeph.phillips at gmail.com Thu Apr 12 23:01:26 2018
From: zeph.phillips at gmail.com (Zeph Phillips)
Date: Fri, 13 Apr 2018 12:01:26 +0900
Subject: [Nirfast] Inversed Values for Jacobian Matrix
Message-ID:
When I try to construct the Jacobian matrix for continuous wave DOT, I
find that my values are inversed than what I expect, according to
literature and other figures (if we assume that the each value is the log
amplitude change/log ua changes). Thus to get the correct DOT image, I have
to multiply these values by a negative one value.
Has anyone run into this issue? Perhaps I am constructing the Jacobian
matrix inappropriately or interpreting it wrong?
Jacobian Construction:
J = jacobian(mesh,0,850);
Optical Properties:
val.mua=0.018;
val.mus=0.69;
val.ri=1.3;
--
______________________
Kind Regards,
*Zeph Phillips*
*zeph.phillips at gmail.com*
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From h.dehghani at cs.bham.ac.uk Fri Apr 13 07:03:15 2018
From: h.dehghani at cs.bham.ac.uk (Hamid Dehghani)
Date: Fri, 13 Apr 2018 12:03:15 +0100
Subject: [Nirfast] Inversed Values for Jacobian Matrix
In-Reply-To:
References:
Message-ID: <66e33c27-17d8-fe59-aff4-0c609bdc991f@cs.bham.ac.uk>
Dear Zeph
Are you using a spectral mesh?
If so, then the Jacobian is in fact Log amplitude/ua and not
Log amplitude change/log ua
If you are using a single wavelength mesh (standard) than when you use
the Jacobian function, it gives you two values for J
J.complex = is the amplitude/mua or kappa
J.complete = is the log amplitude/mua or kappa
The plot you show, appears correct to me.
Hamid
On 13/04/2018 04:01, zeph.phillips at gmail.com wrote:
> When I try to construct the Jacobian matrix for continuous wave DOT, I
> find that my values are inversed than what I expect, according to
> literature and other figures (if we assume that the each value is the
> log amplitude change/log ua changes). Thus to get the correct DOT image,
> I have to multiply these values by a negative one value.
>
> Has anyone run into this issue? Perhaps I am constructing the Jacobian
> matrix inappropriately or interpreting it wrong?
>
> Jacobian Construction:
> J = jacobian(mesh,0,850);
>
> Optical Properties:
> val.mua=0.018;
> val.mus=0.69;
> val.ri=1.3;
>
>
>
>
> --
> ______________________
> Kind?Regards,
> *Zeph Phillips*
> /zeph.phillips at gmail.com/
>
>
> _______________________________________________
> Nirfast mailing list
> Nirfast at public.kitware.com
> https://public.kitware.com/mailman/listinfo/nirfast
>
--
--------------------------
Hamid Dehghani, PhD, MIPEM
Professor of Medical Imaging
School of Computer Science
Co-Director, Physical Sciences for Health Doctoral Training Centre
University of Birmingham
B15 2TT
0121 414 8728
https://www.cs.bham.ac.uk/~dehghanh/mi-lab.html