Input Images

The diffusion-weighted images that are to be analysed consist of multiple images with the same slice locations but with different contrast due to diffusion weighting. They may be organised in one of three ways, and you must tell the diffusion analysis tool in which way they are organised by the settings in the Input Configuration panel:

diff_input_panel

  • Multiple input images (one per diffusion-weighting). You have as many input images are there are diffusion weightings. Each image contains all slice locations that you want to analyse.

  • Multiple input images (one per slice location). You have as many input images are there are slice locations. Each image contains all the diffusion weightings for that slice.

  • Single input image (all diffusion-weightings and slices). You have just one input image. This image contains all the data (all diffusion-weightings and slice locations) to be analysed. If this is the case, then you must also tell the tool about the ordering of data within this image:

  • Different diffusion-weightings are contiguous in image file. Select this option if the ordering of slices has all diffusion-weightings for the first slice location followed by all diffusion-weightings for the second slice location, etc.

  • Different slice locations are contiguous in image file. Select this option if the ordering of slices has all slice locations for the first diffusion-weighting followed by all slice locations for the second diffusion-weighting, etc.

Select the single input image by clicking on the open and using the file chooser to select the input image, or by pressing the right mouse button and selecting from the menu of recently-used images.

You must also tell the tool how many diffusion-weightings are in the image so that it can distinguish diffusion-weightings from slice locations. A cross-check is also performed between the number you set here and the number of gradient vectors and b-matrices defined in your gradient specification file.

If you selected either of the first two options (multiple input images), then the window changes appearance to that below.

diff_input_setup_multiple_input

The panel below the "Input images:" label shows the current list of selected input images. You use the:

  • select_images_button button to select a new set of images and put them to this list.
  • add_images_button button to select a some more images and add them to this list.
  • remove_all_button button to remove all the images from the list.
  • remove_selected_button button to remove the selected the image(s) from the list (you must first click image(s) in the list to select them).
  • move_up_button and move_down_button buttons to move the selected image(s) up or down the list. Images must be in the correct order for analysis - either in the correct slice order, or in the correct diffusion-weighted order to match the gradient vectors and b-matrices in the gradient specification file. Use these buttons to reorder them if they are not.