vich Support for the k-Wave MATLAB toolbox en-US Tue, 12 May 2026 23:29:58 +0000 http://bbpress.org/?v=1.0.2 q http://www.k-wave.org/forum/search.php http://www.k-wave.org/forum/topic/modeling-heterogeneity-of-real-tissues#post-7013 Thu, 22 Aug 2019 17:27:23 +0000 Bradley Treeby 7013@http://www.k-wave.org/forum/ <p>Hi Farnaz,</p> <p>We haven't done any more work on this. <a href="https://doi.org/10.1109/TUFFC.2011.1868">This paper</a> by Gianmarco Pinton might be helpful.</p> <p>Brad. </p> http://www.k-wave.org/forum/topic/geforce-gt-630-quadro-p6000#post-6956 Tue, 09 Jul 2019 11:52:11 +0000 Seneca 6956@http://www.k-wave.org/forum/ <p>I am following the issue. </p> http://www.k-wave.org/forum/topic/geforce-gt-630-quadro-p6000#post-6947 Tue, 02 Jul 2019 08:39:15 +0000 Jiri Jaros 6947@http://www.k-wave.org/forum/ <p>Hi Rola,<br /> does the CUDA code print out any error message?</p> <p>Best<br /> Jiri </p> http://www.k-wave.org/forum/topic/modeling-heterogeneity-of-real-tissues#post-6938 Fri, 28 Jun 2019 09:06:55 +0000 Farnaz 6938@http://www.k-wave.org/forum/ <p>Hi, </p> <p>Have you published anything on this matter? I have difficulty in setting realistic speckle noise for real tissue (e.g. breast tissue) </p> <p>If I were to add uniformly distributed random speckle noise in the density domain with mean distribution of a specific number of reflectors per lambda or lambda^2 (2,3,etc.)(having a 5e6Mhz frequency and speed of sound varying 1300-1800 and dx=3.6765e-5).<br /> How this would be possible having a grid size not matched with the lambda^2 requirements? Can one create an arbitrary density domain independent of dx? </p> <p>Best,<br /> Farnaz </p> http://www.k-wave.org/forum/topic/geforce-gt-630-quadro-p6000#post-6892 Sat, 22 Jun 2019 15:13:40 +0000 Rola 6892@http://www.k-wave.org/forum/ <p>Dear all, </p> <p>I am running a simulation in the GPU (GeForce GT 630 Quadro P6000) but something strange is happening, when I try to load the output.h5 I cannot access the data, I have the following error:</p> <p>Error using h5readc<br /> The filename specified was either not found on the MATLAB path or it contains unsupported characters.</p> <p>Error in h5read (line 58)<br /> [data,var_class] = h5readc(Filename,Dataset,start,count,stride);</p> <p>Therefore, when I run my simulations using a GeForce GT 630 Quadro P5000 I do not have the same error, I can have access to the data. Do you have any idea on what is going wrong?</p> <p>Best </p> http://www.k-wave.org/forum/topic/modeling-heterogeneity-of-real-tissues#post-4357 Mon, 03 Mar 2014 15:34:47 +0000 Anthony 4357@http://www.k-wave.org/forum/ <p>Thanks for your answer Bradley,</p> <p>I will try to play with the parameters and see how the backscatter behaves... A sensitivity analysis on my HIFU field will probably also be a good start.</p> <p>Anthony </p> http://www.k-wave.org/forum/topic/modeling-heterogeneity-of-real-tissues#post-4353 Fri, 28 Feb 2014 18:28:59 +0000 Bradley Treeby 4353@http://www.k-wave.org/forum/ <p>Hi Anthony,</p> <p>The values used for this particular simulation were chosen arbitrarily (but hopefully in a vaguely plausible way). I think what is probably most important for imaging simulations is that the backscatter has the right statistics. For example, you could establish a correlation between the standard deviation of the Gaussian noise added to the sound speed/density, and the received backscatter (Szabo's book has some expressions for backscatter if you need them). Then, you could choose the noise statistics for different tissue types based on experimentally measured values of backscatter from the literature.</p> <p>One of my students did some work on creating "equivalent scattering distributions" to give the correct backscatter statistics, but we haven't published anything on it yet. Depending on which parameters you are interested in, the scatterer distribution is not unique. For HIFU, you may also have to consider other aspects of the scattering. Unfortunately, I haven't found much literature on defining small-scale tissue heterogeneities for grid-based models.</p> <p>Hope that helps,</p> <p>Brad. </p> http://www.k-wave.org/forum/topic/modeling-heterogeneity-of-real-tissues#post-4348 Thu, 27 Feb 2014 16:22:07 +0000 Anthony 4348@http://www.k-wave.org/forum/ <p>Hi Brad,</p> <p>In the example "Simulating B-mode Ultrasound Images", you model the heterogeneity of the medium by adding scatterers as a (bounded) gaussian noise on speed of sound and density.</p> <p>I made a quick bibliographic search and did not find anything precise about modeling the heterogeneities in the tissue. Actually, most of the papers I found are focused on the size (and shape) of the scatterers, estimated from image processing (or histology) but I could not find anything about the statistic distribution of the density and speed of sound among the tissue. </p> <p>Do you have some bibliographic references about this or was your example simply based on the visual aspect of the simulated B-mode images, which look realistic? </p> <p>I just want to have a look at the defocusing that occurs due to heterogeneity and seems not to be negligible for HIFU simulations.</p> <p>Best regards,<br /> Anthony </p>