Difference between revisions of "Visualizing Images: Displaying images using the triplanar-dual view"

Latest revision as of 15:33, 21 February 2012

The triplanar-dual view displays two image datasets (referred to as Image A and Image B) and a blended version of both Image A and Image B from three orthogonal planes.

To view image datasets using this view
1 Open two 3D or 4D images, which become known as Image A and Image B.
2 Load Image B into Image A.
3 Select Image > Views > Triplanar-Dual. The triplanar-dual view appears in an image window.

The image window for the triplanar-dual view is quite similar to the image window for the triplanar view. The File and Options menus contain the same commands except for one command-the Options menu for the triplanar view contains the command Link to Another TriImage. Since the triplanar-dual view shows two datasets in the image window and allows you to manipulate them together, linking to another image is not necessary. Most of the icons and buttons on the toolbars for both views are the same with one primary difference: The triplanar-dual view allows you to create VOIs on the images; the triplanar view does not.

Like the triplanar view, you can use the icons and buttons on the toolbar to change magnification, draw, change colors, change opacity, and apply a new intensity to selected voxels in the images.

Showing and hiding axes, cross hairs, and Talairach grid

By default, the triplanar-dual view automatically shows the axes and cross hairs on Image A, Image B, and the blended dataset.

To show or hide axes on images
To hide the axes, select Options > Show Axes (Figure 2). The check mark disappears from the check box in front of the command on the menu, and the axes disappear from all of the images.

To display the axes on the images again, simply select Options > Show Axes. The check mark reappears in the check box in front of the command.

To show or hide cross hairs
Showing or hiding cross hairs works just as showing or hiding axes. To hide the cross hairs, select Options > Show Cross Hairs. To show them, select Options > Show Cross Hairs again.
To show or hide the Talairach grid
By default, the Talairach grid does not automatically display on the images unless you specifically select it to do so. To show the grid, select Options > Show Talairach Grid. The grid appears on all of the images shown in the triplanar-dual view. When you want to hide the grid, select Options > Show Talairach Grid again.

Creating VOIs on images

You can create point or line VOIs on the images.
To create point VOIs
1 Click .
2 Click in the image where you want to create a point.
3 Repeat steps 1 and 2 for all other desired points.

To draw line VOIs
1 Click .
2 Click in the image where the line should begin and drag the line to where it should end.
The numbers beneath the line indicate the length of the line in millimeters.
To change the line VOI, simply click on the VOI and then drag it to another position in the image.

You can only create one line VOI per orthogonal plane, although you can create a line VOI in each one of the three orthogonal planes.

To delete line VOIs
You cannot delete a line VOI. However, you can remove the display of the line VOI on the image. To do so, click . The line VOI disappears.

Figure 3. Triplanar-Dual window

File	Close Frame-Closes this window.
Options	Show Axes-Displays the XY (top left), ZY (top right), and ZX (bottom left) axes on the images.
	Show Cross Hairs-Displays the cross-hair lines on the images. When you move these lines on one image, it also moves to the corresponding points all of the other images.
	Show Talairach Grid-Displays a Talairach (stereo tactic) grid on the images.
Traverse image	Aligns two images.
Magnify image 2.0x	Enlarges the images to twice their current size. It might be necessary to manually resize the window and use scroll bars to view all of the images.
Magnify image 0.5x	Reduces the images to half of their current size.
Magnify image 1.0x	Restores the images to their original size.
Draw line VOI	Draw a line VOI.
Identify center of volume	Reassigns a new center to each dataset. The location that you select appears in the center of each image.
Alignment tool	Allows you to apply a transformation matrix to an image dataset.
Applies rotations and translations	Applies the rotations and translations made to the images.
Add point	Draws a point on an image. This point is only on the image you select.
Initiate new VOI	Indicates that the next VOI is a new VOI rather than a change to the currently existing VOI.
Delete point VOI	Removes the point VOI from the image.
Identify crop volume	Displays the bounding box, which is outlined in red, on each image.
Crops image delineated by the bounding cube	Displays in a separate image window only the area enclosed by the bounding box. When you click this icon, the Crop Image dialog box opens.
Draw using a brush	Allows you to draw with a brush on the image.
Picks up a color from the image	Changes the color of the paint used to the color selected on the image.
Fills an area with desired color	Allows you to fill an area with color. When you select this icon, the Paint Grow dialog box opens.
Erases a portion of the image	Removes the paint from the specific spot that you select.
Erase all paint	Removes all paint from all of the images.
Draw using small size	Indicates the size of the paint brush tip. Click this icon to paint one voxel each time the mouse button is clicked.
Draw using medium size	Indicates the size of the paint brush tip. Click this icon to paint 16 voxels (4 x 4 square) each time the mouse button is clicked.
Draw using large size	Indicates the size of the paint brush tip. Click this icon to pain 100 voxels (10 x 10 square) each time the mouse button is clicked.
Change intensity level of paint	Allows you to change the intensity value of the paint. When you click this icon, the Desired Paint Intensity dialog box opens.
You can specify an intensity between -32,768 and 32,767. After you type an intensity level, the icon displays the level you entered.
Change paint color	Changes the color of the paint used. This icon is often used in conjunction with the Draw icons. When you click this icon, the Pick Paint Color dialog box opens. After you change the color, this icon displays the color.
Opacity	Allows you to change the opacity of the paint. When you click this icon, the Paint Opacity dialog box opens.
Changes image where painted	Permanently applies the intensity level to the images.
Undo last region paint	Removes paint from the last area to which it was applied.
Calculate volume of paint	Determines the volume, or number of pixels, in the painted area of the image.
Image A	Performs the action only on Image A.
Image B	Performs the action only on Image B.
Both	Performs the action on both Image A and Image B.

To delete point VOIs
1 Click the first point on the image aligning the middle of the cursor with the center of the point.
2 Click . The point disappears.
3 Repeat the first two steps for every point you want to delete.

Aligning the datasets

The Alignment Tool icon, , allows you to create a new transformation matrix for the dataset.
< 1 Click .
A closed angle appears on each of the images in the triplanar-dual view. On Image A, the angle is red; on Image B, it's yellow; on the blended image, the angle is green.
2 Move the cursor to the arrow on the thin line to the right, and align the cursor with the end of the arrow. At this time, the cursor should be a red cross.

3 Change the size of the angle by dragging the arrow on the thin line up or down depending on the type of angle you want to create. The exact number of degrees appear on the left below the angle.
4 Release the mouse button when you reach the desired number of degrees.

5 Click on the image or on any other area of the triplanar-dual view. The arrows disappear from the angle.
6 Click on the angle again to be able to change the angle again. The arrows reappear and you can repeat the previous steps.

Finding the center of image datasets

To find the center of the dataset, click . The center of each image dataset, shown as , appears in each image in the triplanar-dual view.

Erasing part or all of drawings

If you used the paint brush to draw on the image, you may at times find a need to erase a part of the drawing or the entire drawing.
File:MIPAV VisualizationTools189.gif

Make sure that you want to erase a part of the drawing or the entire drawing. There is no undo.
To erase a part of the drawing
1 Select the image that contains the drawing you want to erase. In other words, select Image A, Image B, or Both.
2 Click .
3 Click on the part of the drawing that you want to erase.
4 Repeat step 3 for as long as needed.

To erase all of the drawing
1 Select the image that contains the drawing you want to erase. Specifically, select Image A, Image B, or Both.
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