<?xml version="1.0" encoding="utf-8"?><feed xmlns="http://www.w3.org/2005/Atom" ><generator uri="https://jekyllrb.com/" version="3.9.2">Jekyll</generator><link href="/feed.xml" rel="self" type="application/atom+xml" /><link href="/" rel="alternate" type="text/html" /><updated>2022-06-01T16:11:35+00:00</updated><id>/feed.xml</id><title type="html">rcallagh</title><subtitle>This is my site</subtitle><author><name>Ross Callaghan</name></author><entry><title type="html">ConFiG - A new state-of-the-art white matter numerical phantom generator</title><link href="/diffusionmri/2020/06/22/config/" rel="alternate" type="text/html" title="ConFiG - A new state-of-the-art white matter numerical phantom generator" /><published>2020-06-22T10:00:00+00:00</published><updated>2020-06-22T10:00:00+00:00</updated><id>/diffusionmri/2020/06/22/config</id><content type="html" xml:base="/diffusionmri/2020/06/22/config/">&lt;p&gt;Here we present &lt;a href=&quot;https://arxiv.org/abs/2003.10197&quot;&gt;ConFiG: Contextual Fibre Growth&lt;/a&gt;, a brand-new state-of-the-art numerical phantom generator capable of creating more realistic synthetic white matter tissues than ever before. We do this by mimicking the way axons grow in nature, following chemical cues in their envrionment. The video below shows a ConFiG phantom alongside a series of virtual histological slices, demonstrating the complex morphology ConFiG can generate.&lt;/p&gt;
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  &lt;iframe src=&quot;https://player.vimeo.com/video/402472645&quot; width=&quot;600&quot; height=&quot;300&quot; frameborder=&quot;0&quot; webkitallowfullscreen=&quot;&quot; mozallowfullscreen=&quot;&quot; allowfullscreen=&quot;&quot;&gt;
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&lt;p&gt;For full details of exactly how we make this happen, check out the full journal article &lt;a href=&quot;https://arxiv.org/abs/2003.10197&quot;&gt;here&lt;/a&gt;&lt;/p&gt;

&lt;p&gt;ConFiG generates microstructurally realistic phantoms as evidenced in the below two figures. Firstly, Figure 1 shows that ConFiG captures the diameter profile well when compared to real axons. Not only that, but fine details like the bulges and bends in fibres are seen in both ConFiG and real fibres - note that none of these fine details are explicitly imposed, but just arise organically from the ConFiG growth algorithm.&lt;/p&gt;

&lt;figure class=&quot;fig-fluid&quot;&gt;
    &lt;a href=&quot;/assets/img/posts/config/diameter_dist.png&quot; class=&quot;img-gallery&quot; data-sub-html=&quot;Figure 1: Comparison of diameter distributions in real axons and ConFiG phantoms. ConFiG is able to capture then general shape of the diameter and coefficient of variation as well as capturing fine details on a per fibre basis such as bulges (shown in d)&quot;&gt;
        &lt;img src=&quot;/assets/img/posts/config/diameter_dist.png&quot; class=&quot;img-fig&quot; /&gt;
    &lt;/a&gt;
    &lt;figcaption&gt; Figure 1: Comparison of diameter distributions in real axons and ConFiG phantoms. ConFiG is able to capture then general shape of the diameter and coefficient of variation as well as capturing fine details on a per fibre basis such as bulges (shown in d) &lt;/figcaption&gt;
&lt;/figure&gt;

&lt;figure class=&quot;fig-fluid&quot;&gt;
    &lt;a href=&quot;/assets/img/posts/config/virthist.png&quot; class=&quot;img-gallery&quot; data-sub-html=&quot;Figure 2: Comparison of a real histological slice and virtual histology from a ConFiG phantom. Whilst not capturing the details of the histological constrast, ConFiG phantoms capture complex morphological features seen in real tissue that no other WM phantom generator is capable of.&quot;&gt;
        &lt;img src=&quot;/assets/img/posts/config/virthist.png&quot; class=&quot;img-fig&quot; /&gt;
    &lt;/a&gt;
    &lt;figcaption&gt; Figure 2: Comparison of a real histological slice and virtual histology from a ConFiG phantom. Whilst not capturing the details of the histological constrast, ConFiG phantoms capture complex morphological features seen in real tissue that no other WM phantom generator is capable of. &lt;/figcaption&gt;
&lt;/figure&gt;

&lt;p&gt;These realistic synthetic tissues also give rise to realistic simulated diffusion MRI (dMRI) signals as shown in Figure 3. Here, we generated three ConFiG phantoms to be representative of three WM regions in the brain. Using these phantoms, we simulated the dMRI signal using the Human Connetome Project (HCP) measurement scheme and compared the simulated signal to real signal from an HCP subject. As Figure 3 shows, the simulated and real signals correspond well, both in terms of direction averaged signal (bottom row) and direction dependent signal (middle row). There is some devation from the real signal at high |n.G| in the middle row (i.e. measuring the signal along the main fibre bundle direction), though this to be expected as the real signal reaches the noise floor and the noise-free simulated signals continue to decay.&lt;/p&gt;

&lt;figure class=&quot;fig-fluid&quot;&gt;
    &lt;a href=&quot;/assets/img/posts/config/hcp_vs_sim.png&quot; class=&quot;img-gallery&quot; data-sub-html=&quot;Figure 3: Comparison of real dMRI signals from an HCP subject and simulated signals from ConFiG phantoms, demonstrating the ability of ConFiG phantoms to reproduce dMRI signals well.&quot;&gt;
        &lt;img src=&quot;/assets/img/posts/config/hcp_vs_sim.png&quot; class=&quot;img-fig&quot; /&gt;
    &lt;/a&gt;
    &lt;figcaption&gt; Figure 3: Comparison of real dMRI signals from an HCP subject and simulated signals from ConFiG phantoms, demonstrating the ability of ConFiG phantoms to reproduce dMRI signals well. &lt;/figcaption&gt;
&lt;/figure&gt;

&lt;p&gt;ConFiG is a valuable new tool, giving us the capability to investigate microstructural features with more detail than ever before. This opens up avenues for thorough validation of exisiting microstructure imaging methods as well as development of exiting new models for microstructure imaging.&lt;/p&gt;</content><author><name>Ross Callaghan</name></author><category term="diffusionMRI" /><category term="diffsionMRI" /><summary type="html">Here we present ConFiG: Contextual Fibre Growth, a brand-new state-of-the-art numerical phantom generator capable of creating more realistic synthetic white matter tissues than ever before. We do this by mimicking the way axons grow in nature, following chemical cues in their envrionment. The video below shows a ConFiG phantom alongside a series of virtual histological slices, demonstrating the complex morphology ConFiG can generate.</summary></entry><entry><title type="html">Hello World</title><link href="/general/2020/05/22/welcome-to-jekyll/" rel="alternate" type="text/html" title="Hello World" /><published>2020-05-22T10:00:00+00:00</published><updated>2020-05-22T10:00:00+00:00</updated><id>/general/2020/05/22/welcome-to-jekyll</id><content type="html" xml:base="/general/2020/05/22/welcome-to-jekyll/">&lt;p&gt;You’ll find this post in your &lt;code class=&quot;language-plaintext highlighter-rouge&quot;&gt;_posts&lt;/code&gt; directory. Go ahead and edit it and re-build the site to see your changes. You can rebuild the site in many different ways, but the most common way is to run &lt;code class=&quot;language-plaintext highlighter-rouge&quot;&gt;jekyll serve&lt;/code&gt;, which launches a web server and auto-regenerates your site when a file is updated.&lt;/p&gt;

&lt;p&gt;To add new posts, simply add a file in the &lt;code class=&quot;language-plaintext highlighter-rouge&quot;&gt;_posts&lt;/code&gt; directory that follows the convention &lt;code class=&quot;language-plaintext highlighter-rouge&quot;&gt;YYYY-MM-DD-name-of-post.ext&lt;/code&gt; and includes the necessary front matter. Take a look at the source for this post to get an idea about how it works.&lt;/p&gt;

&lt;p&gt;Jekyll also offers powerful support for code snippets:&lt;/p&gt;

&lt;figure class=&quot;highlight&quot;&gt;&lt;pre&gt;&lt;code class=&quot;language-ruby&quot; data-lang=&quot;ruby&quot;&gt;&lt;span class=&quot;k&quot;&gt;def&lt;/span&gt; &lt;span class=&quot;nf&quot;&gt;print_hi&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;nb&quot;&gt;name&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
  &lt;span class=&quot;nb&quot;&gt;puts&lt;/span&gt; &lt;span class=&quot;s2&quot;&gt;&quot;Hi, &lt;/span&gt;&lt;span class=&quot;si&quot;&gt;#{&lt;/span&gt;&lt;span class=&quot;nb&quot;&gt;name&lt;/span&gt;&lt;span class=&quot;si&quot;&gt;}&lt;/span&gt;&lt;span class=&quot;s2&quot;&gt;&quot;&lt;/span&gt;
&lt;span class=&quot;k&quot;&gt;end&lt;/span&gt;
&lt;span class=&quot;n&quot;&gt;print_hi&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;(&lt;/span&gt;&lt;span class=&quot;s1&quot;&gt;'Tom'&lt;/span&gt;&lt;span class=&quot;p&quot;&gt;)&lt;/span&gt;
&lt;span class=&quot;c1&quot;&gt;#=&amp;gt; prints 'Hi, Tom' to STDOUT.&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/figure&gt;

&lt;p&gt;Check out the &lt;a href=&quot;https://jekyllrb.com/docs/home&quot;&gt;Jekyll docs&lt;/a&gt; for more info on how to get the most out of Jekyll. File all bugs/feature requests at &lt;a href=&quot;https://github.com/jekyll/jekyll&quot;&gt;Jekyll’s GitHub repo&lt;/a&gt;. If you have questions, you can ask them on &lt;a href=&quot;https://talk.jekyllrb.com/&quot;&gt;Jekyll Talk&lt;/a&gt;.&lt;/p&gt;</content><author><name>Ross Callaghan</name></author><category term="general" /><summary type="html">You’ll find this post in your _posts directory. Go ahead and edit it and re-build the site to see your changes. You can rebuild the site in many different ways, but the most common way is to run jekyll serve, which launches a web server and auto-regenerates your site when a file is updated.</summary></entry></feed>