title: Overlay mask to the next time point in Simple ITK
body: <p>We are working on a problem of lesion tracking. So we have 3-d series of dicom images for two time points. Lesions are marked on time point - 1, using this we want to project the same lesions to the time point 2.</p>
  <p>Currently we are following the approach below:</p>
  <ul>
  <li><p>Register 3-d series of images from timepoint-1(moving_image) with 3-d series of images from timepoint-2(fixed_image).</p>
  </li>
  <li><p>Use the transform from the above registration to resample the masks on timepoint-1 with fixed image on timepoint-2 ==== This gives fixed_mask on time point 2.</p>
  </li>
  <li><p>Overlay this fixed_mask to fixed_image to get the lesions on the timepoint-2.</p>
  </li>
  </ul>
  <p>Doing the above gives all blank images as the mask is mostly filled with null except that one tiny point.</p>
  <p>Am I following the right approach? Is there any other way to overlay the mask from one time point to the next?</p>