Hi Dr. Treeby and Dr. Cox
I am using k-wave toolbox to generate my data set and use this data for image reconstruction.
I did it by analytical algorithm like back projection.
I want to use model-based algorithm to reconstruct absorption so for each iteration of model based algorithm i need to simulate forward model to generate pressure signals from corresponding optical absorption.
is it possible to run the forward model for model-based image reconstruction?
best
Moein Mozaffarzadeh
k-Wave
A MATLAB toolbox for the time-domain
simulation of acoustic wave fields
model-based image reconstruction
(5 posts) (3 voices)-
Posted 8 years ago #
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Hi Moein,
Yes, you can use k-Wave as a forward model for model-based image reconstruction, although the most general image reconstruction algorithm incorporated directly into k-Wave is time reversal. There are some examples describing that. 'Model-based' image reconstruction is not a very specific term - all image reconstruction techniques are based on models of the acoustic propagation, although they are not always explicitly stated as such. Sometimes it is used to describe an approach where a matrix formulation of the forward model is used in an iterative minimisation-based reconstruction. Whether or not that is feasible depends on the size of the problem you are tackling. A related approach that doesn't use matrices is based on adjoint equations. Anastasio has done some good work on this recently. The adjoint for k-Wave's forward model is not yet incorporated into the code, but there is a paper that includes a description of how you can do it using the existing toolbox here: arxiv.org/abs/1602.02027
Hope that helps.
BenPosted 8 years ago # -
Dear Dr. Cox
thanks for your help. as you mentioned there are some cases that are working with matrix formulation of the forward model. this is my goal. I want to have the forward matrix model and use iterative minimization approach. how can I have the forward model matrix in k-Wave? is it even possible?
best
Moein MozaffarzadehPosted 8 years ago # -
Hi Moein,
You could in theory build the matrix laboriously by putting point sources at every point, one-after-another, and measuring the response everywhere for all times, and putting those measured 'Green's functions' into a matrix. Not sure what the point of that would be though. The matrix would likely be huge. As I mentioned before, Mark Anastasio's group have written a paper on constructing a matrix version of the forward model that k-Wave is based. See Huang, Chao, et al. "Full-wave iterative image reconstruction in photoacoustic tomography with acoustically inhomogeneous media." IEEE transactions on medical imaging 32.6 (2013): 1097-1110. There has also been work in this area by the group of Daniel Razansky in Munich. They use a different discrete model but it is matrix based.
Best wishes,
Ben
Posted 8 years ago # -
Moein,
Another article which you might find helpful, also by Anastasio et al., is "An Imaging Model Incorporating Ultrasound Transducer Properties for Three-Dimensional Optoacoustic Tomography," IEEE Transactions on Medical Imaging, Vol. 30, No. 2, Feb 2011.
Best,
OsmanPosted 7 years ago #
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