http://www.k-wave.org/forum/topic/how-to-simulate-speckle-pattern-in-photoacoustic-imaging Support for the k-Wave MATLAB toolbox en-US Wed, 13 May 2026 00:22:31 +0000 http://bbpress.org/?v=1.0.2 q http://www.k-wave.org/forum/search.php http://www.k-wave.org/forum/topic/how-to-simulate-speckle-pattern-in-photoacoustic-imaging#post-8070 Thu, 25 Feb 2021 22:52:29 +0000 lokesh 8070@http://www.k-wave.org/forum/ <p>Hi Ben,<br /> Yes, it helps me for a better understanding of simulations.</p> <p>I tried simulating PA signals with random initialization of medium.sound_speed and medium.density. But, no success. </p> <p>As you mentioned the issue maybe with the grid size since the simulation was done using a higher frequency (21 MHz). </p> http://www.k-wave.org/forum/topic/how-to-simulate-speckle-pattern-in-photoacoustic-imaging#post-8015 Tue, 19 Jan 2021 20:39:11 +0000 bencox 8015@http://www.k-wave.org/forum/ <p>Hi lokesh,</p> <p>US scattering is caused by spatial variations in a medium's acoustic properties, so in k-Wave the way to do it has to be via the <code>medium.sound_speed</code> and <code>medium.density</code> inputs. Making these properties random (with different means and standard deviations for different regions perhaps) might be worth a try.</p> <p>It's tricky, though, because speckle arises when scattering occurs from scatterers that can't be separately resolved by the imaging system, so if the resolution length is L, to model speckle you need to be able to model scatterers spaced by distances much shorter than L. Perhaps many tens of scatterers in a L^3 volume would be needed. That is difficult to achieve in k-Wave as it is grid based, so you end up needing a very finely spaced grid.</p> <p>Something else to ponder is that speckle is essentially a narrowband phenomenon, and k-Wave is designed for modelling broadband signals, because photoacoustic waves are naturally broadband. </p> <p>Does that help? </p> http://www.k-wave.org/forum/topic/how-to-simulate-speckle-pattern-in-photoacoustic-imaging#post-7993 Wed, 06 Jan 2021 02:23:56 +0000 lokesh 7993@http://www.k-wave.org/forum/ <p>Hi Bradley, sorry for the late update I didn't see the forum for many days.</p> <p>I struck at defining a medium that is similar to US imaging, where the medium is defined with a number of scatterers.<br /> In PA imaging, the source is defined as PA absorbers and gives the US signal. I have a confusion between the source and the medium. </p> http://www.k-wave.org/forum/topic/how-to-simulate-speckle-pattern-in-photoacoustic-imaging#post-7900 Sun, 01 Nov 2020 22:29:07 +0000 Bradley Treeby 7900@http://www.k-wave.org/forum/ <p>Hi lokesh,</p> <p>What part are you stuck on?</p> <p>Brad </p> http://www.k-wave.org/forum/topic/how-to-simulate-speckle-pattern-in-photoacoustic-imaging#post-7882 Fri, 16 Oct 2020 23:39:23 +0000 lokesh 7882@http://www.k-wave.org/forum/ <p>Hi,<br /> I am working with high frequency photoacoustic simulations (12-30 MHz). Please help me to simulate a photoacoustic image that has speckle patten similar to US image.<br /> Thanks. </p>