title: Bulk renaming using regexp
body: <p>I am using Bulk Rename Utility to change the name of a lot of files. The files have a name similar to this one:</p>
  
  <pre><code>Albert_Silva-MR11_0.dcm
  </code></pre>
  
  <p>On each folder, there are files with the same name, only changing the last number, for example:</p>
  
  <pre><code>Albert_Silva-MR11_13.dcm
  </code></pre>
  
  <p>So, I was trying to find the regex expression to match everything until the last _ character in the file, in order to substitute it by "slice". In the example, "Albert_Silva-MR11_0.dcm" would then become "slice_0.dcm". Note that some file names have more than two ocurrences of _, so looking for the second _ wouldn't be valid.</p>