k-Wave

1. wsimson
   

   Member
   Joined: Feb '19
   Posts: 12

   Hi all,

   I'm having an interesting issue with a simulation of a filament phantom simulation. Over greater depths, the PSF of the point scatterer seems to double (see image). The Images are made with an aperture of 64 elements and 3 plane-wave coherent compounding with transmit angles of [-8, 0,8].
   Two further points are that the same artifacts are visible when only one plane wave is used, and can also be seen in the channel data. This only occurs in the simulation but not when using data of in-silico phantoms.

   One thought of mine is that both interfaces of the discretization cell are being imaged, but that doesn't explain to me why the reflections in the top if the image are still so tightly bound. Another thought I had was the edge waves some how cause this. I'm looking for any insight into why this might happening in my sims.

   Thanks,
   Walter
   Filament phantom
   
   CIRS Phantom image with the same beamforming code.
   
   one point at mid-depth
   

   Posted 3 years ago #

2. Bradley Treeby
   

   Developer
   Joined: Mar '10
   Posts: 1,643

   Hi Walter,

   I'm not sure to be honest. Have you tried looking at the animation of the wave simulation as it runs to see if you can see, e.g., multiple reflections when the wave interacts with the filament? It is puzzling why they spread out at greater depths. Is the speed of sound in the beam-forming code correct? One thought - if you're using absorption, the waves will travel at a slightly different speed to medium.sound_speed due to dispersion, so you could try re-running with the absorption turned off to see if that's the culprit.

   Brad.

   Posted 3 years ago #

3. wsimson
   

   Member
   Joined: Feb '19
   Posts: 12

   I looked into the animation and seem to have cleared this error. I believe it was operator error in this case.

   Posted 3 years ago #

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