The image viewer used on this website is a simplified version of digital MRI and X-Ray viewers that you find in hospitals and imaging centres. Learn how to use the controls by clicking on the topics below.

• Stack (scroll)

  MRI sequences may be made up of several slices. A typical image sequence will have approximately 12-18 slices. Stacking allows you to move through the sequence slices. To move through the slices:

  1. Select the Stacking tool
  2. Move the mouse cursor into one of the images
  3. Click and hold down the left mouse button.
  4. While holding down the left mouse button, move your mouse up or down. Move the mouse down to move forward through the slices, and up to move backward through the slices.

  Tips:
  

  • When multiple images are displayed, the viewer will determine if the images can be synchronized, and if so, the images will scroll together.
  • If your mouse has a scroll wheel, you can also scroll through the slices using the wheel (may not work in some browsers).
  • Likewise, a trackpad on a laptop that supports scrolling can be used to scroll though images by using the trackpad's scrolling function
  • You can also scroll through the slices using the scroll bar to the right side of each image.

• Window

  Windowing allows you to adjust the brightness and contrast of the images which can help better highlight features.

  1. Select the Window tool
  2. Move the mouse cursor into one of the images
  3. Click and hold down the right mouse button.
  4. While holding down the right mouse button, move your mouse up and down to adjust brightness, or left and right to adjust contrast.
     • Up makes the image brighter
     • Down makes the image darker
     • Left increases the contrast (dark areas get darker, light areas get lighter)
     • Right decreases the contrast (dark areas get lighter, light areas get darker).
     • Moving the mouse diagonally adjusts both brightness and contrast at the same time.

  Tips:
  

  • Windowing is applied to each sequence independently (e.g., windowing the T1 sequence does not affect the STIR sequence), but the settings are applied to all images in the selected sequence.
  • Most images will benefit from an increase in contrast.

• Zoom

  Zooming lets you magnify the image to get a closer look at specific features.

  1. Select the Zoom tool
  2. Move the mouse cursor into one of the images
  3. Click and hold down the right mouse button.
  4. While holding down the right mouse button, move your mouse up and down to zoom in and out.

• Move

  The Move tool is often used in conjunction with the Zoom tool. It allows you to move a magnified image around in the viewing area.

  1. Select the Move tool
  2. Move the mouse cursor into one of the images
  3. Click and hold down the left mouse button.
  4. While holding down the left mouse button, move your mouse up, down, left, and right. The image will move with the cursor.

• Annotate

  The Annotate tool lets you draw on an image.

  1. Select the Annotate tool.
  2. In the menu that opens under the tool, select a colour and stylus.
  3. Move the mouse cursor into one of the images.
  4. Click and hold down the left mouse button.
  5. While holding down the left mouse button, move your mouse around. The stylus will be drawn on the image.

  Tips:
  

  • To remove the last annotation, click the button.
  • To clear all annotations in the selected series, click the button.
  • Caution: this action will not remove the annotations from the moderators view.

• Reset

  The Reset tool resets any manipulations made to a sequence (e.g., zoom, window), and removes all annotations.

  1. Select a sequence by clicking the mouse on an image. A sequence is selected when there is a red box around it.
  2. Click the Reset button.

• Horizontal Flip

  Use the Horizontal Flip tool to view a mirror image of the displayed image.

  1. Select a sequence by clicking the mouse on an image. A sequence is selected when there is a red box around it.
  2. Click the Horizontal Flip button.

• Thumbnails

  The online image viewer can display a maximum of two sequences or images. If more than two sequences are available, you will be able to view thumbnails (miniature versions of the images), and choose which sequence or image is displayed in the large image panes.

  1. Open the thumbnail view by clicking on the Thumbnail button.
  2. Click on a thumbnail and hold down the mouse button.
  3. Drag the thumbnail into one of the large image panes.
  4. Release the mouse button.

• Synchronize

  When viewing T1W and STIR sequences of the same scan side by side, it is often preferable to scroll both sequences at the same time. This is the default behaviour of this online image viewer. However, the synchronization will be broken when dragging and dropping images from the thumbnail bar. You can manually turn synchronization on or off using the Syncronize button.

• Toggle Layout

  Toggle between one image pane or two. A single pane will give you a larger viewing area for an image.

• Toggle Rulers

  Toggle the display of the rulers on the left and bottom of the images.
  Tips:

  • A ruler interval is 1 cm.
  • Rulers can be moved. Click and drag a ruler to wherever you need it.

• Measure

  The Measurement tool lets you measure the distance between two arbitrary points.
  

  1. Select the Measurement tool
  2. Move the mouse cursor into one of the images
  3. Click and hold down the left mouse button.
  4. While holding down the left mouse button, move your mouse around. A straight line will be drawn on the image from the point where you first clicked the mouse to the current location of the mouse pointer.
  5. Release the mouse button to complete the line.
  6. The distance between the start and end points will be displayed above the line.
  7. Delete a measurement by clicking the "X" next to the measurement.

  Tips:

  • Measurements are specific to the slice where the measurement was done.

• Audio Controls

  If a case has an audio track, audio controls will be displayed in the control bar. The audio track usually contains a description of the current case and points out features of the case. It is important that you listen to the audio track as you progress through the cases. Use the Pause and Rewind buttons as required so that you can interact with the images based on the audio cues. You may also view or hide the transcript of the audio track by clicking on the Transcript button.

  • Play the audio track
  • Pause the audio track
  • If the track is playing, rewind 5 seconds. If the track is paused, rewind to the beginning.
  • If the track is playing, fast-forwards 5 seconds.
  • Adjust the volume
  • View or hide a transcript of the audio track, if available.

  When a case has a transcript of the audio or a textual desciption, you may flip through the transcript using the Rewind and Fast Forward buttons in the left-hand side of the transcript box.

  1. Open the transcript (if not already open) by clicking
  2. Use and to navigate through the transcript

• Image Features

  Many cases in the MRI course will have features described in the audio track, and may have additional features that are not mentioned in the audio track. Some of these features are highlighted when you move your mouse pointer over the feature on a particular slice.

  • While the feature is highlighted, you can click on it to make the outline stick.
  • Touch the image again to remove the outline.

  When the audio track points out features that you are expected to find, a feature counter will appear in the menu bar telling you how many features you have found out of the total number of features hidden. The audio track will automatically pause until you have found all the features. If you get stuck, you may press Play to continue the audio.

• Case Navigation

  The current case number is displayed in the top-right corner of the image viewer. Navigate through the cases using the following controls:

  • Return to the module introduction/case list
  • Go to the previous case
  • Go to the next case

• Other tips and tricks
  

  • Maximize your browser window so that it fills the entire screen. The larger the images, the better you will be able to see the features.
  • When selecting some controls, directional arrows will appear to the right of the control. You can click on these arrows to perform the same functions as moving the mouse in that direction while holding down the appropriate button.
  • Because some controls are operated with the left mouse button and others with the right mouse button, you can have two controls selected at the same time, e.g., Stack and Window, or Move and Zoom.