http://www.k-wave.org/forum/topic/loss-of-intensity-for-shallow-structures Support for the k-Wave MATLAB toolbox en-US Tue, 12 May 2026 21:37:35 +0000 http://bbpress.org/?v=1.0.2 q http://www.k-wave.org/forum/search.php http://www.k-wave.org/forum/topic/loss-of-intensity-for-shallow-structures#post-9049 Sat, 16 Mar 2024 02:34:05 +0000 daga_pankaj 9049@http://www.k-wave.org/forum/ <p>It is definitely that. Reducing the alpha coefficient really helped! </p> http://www.k-wave.org/forum/topic/loss-of-intensity-for-shallow-structures#post-9048 Sat, 16 Mar 2024 02:29:03 +0000 daga_pankaj 9048@http://www.k-wave.org/forum/ <p>Thanks for replying!</p> <p>Do you suggest just tuning the alpha coefficient and power or maybe experimenting with some other TGC functions rather than uniform exponential gain? </p> http://www.k-wave.org/forum/topic/loss-of-intensity-for-shallow-structures#post-9047 Fri, 15 Mar 2024 16:43:51 +0000 Bradley Treeby 9047@http://www.k-wave.org/forum/ <p>Is it an issue with the time-gain-compensation increasing the amplitude of the deeper structures too much? </p> http://www.k-wave.org/forum/topic/loss-of-intensity-for-shallow-structures#post-9046 Wed, 13 Mar 2024 18:02:48 +0000 daga_pankaj 9046@http://www.k-wave.org/forum/ <p>I am simulating image formation for a phantom which is slightly on the deeper side (80mm).</p> <p>I am using a signal at 5 MHz and what I notice is basically a smooth degradation of the signal from bottom to top i.e. the bottom structures are more easily visible and the signal drops to almost zero from 30-40 mm upwards. I tried to set the focus at various depths but the result is the same.</p> <p>Additionally, I doubled the PML size in both directions as well.</p> <p>The focus int he elevation plane is set to the default of 19mm as in the US linear transducer example.</p> <p>Looking for some advise on trying out things that could help with diagnosing the issue. Similar phantoms at 40 mm depth have all resulted in ok looking images. So, it seems to be a depth issue. </p>