Image Viewer > Advanced Viewing > Multiplanar Reconstruction (MPR)

The MPR workspace has a fixed 2x2 image box layout. The top left image box always contains the source images from which the MPR was started. Each of the three other image boxes are controlled by its own MPR line (or slice line) drawn on a separate reference image, which are colour-coded and labeled for ease of identification.

The MPR line represents the orientation of the images it controls in much the same way reference lines indicate the positions of images in different display sets relative to each other (you can actually turn on reference lines and see how they coincide with the MPR lines). Every generated image will always extend from the top to the bottom of the stack of reference images. One end of each MPR line is marked with an arrowhead to indicate the orientation of the images it generates (the arrow always points from the left side to the right side of the generated images).

Starting MPR

To view a set of images with the MPR Workspace, simply right click on a display set and select the Open with MPR tool. Alternatively, you can select the MPR tool from either the Tools menu or the main toolbar to start MPR using the currently selected display set. If the tool is not visible or is disabled, then there are not enough images in the display set to start MPR.

Screenshot

There are some restrictions on the kind of source images from which MPR can be started:

•	There must be at least three images in the display set.

•	All the images must come from the same study and series.

•	All the images must have the same frame of reference.

•	All the images must have the same image orientation (relative to the patient).

•	The spacing between consecutive images must be consistent.

•	The images may not have a horizontal gantry tilt 1.

Controlling MPR

There are many ways to change the orientation of the three controllable views in the MPR Workspace, all of which have support for undo/redo.

•	Drag the end points of the corresponding MPR line, such as you would a ruler measurement graphic. Screenshot

•	Drag the entire MPR line, much as you would move any measurement or annotation graphic. Screenshot

•	Select a Reslice MPR Tool from the context menu, the drop down on the main toolbar, or from the Tools main menu. You can then draw a new MPR line such as you would draw a new ruler measurement. Screenshots

Note that, with this tool, you can actually draw the MPR line on any other image and not just the original images, provided the image is not in the display set that corresponds to the line. For example, you can draw the MPR (1) line on either MPR (Identity), MPR (2) or MPR (3), but not MPR (1) itself. Screenshot

Drawing the MPR (2) line on the MPR (2) images is not allowed...

But drawing the MPR (1) line on MPR (2) is!

•	Select the Reset All Tool from the context menu, the drop down on the main toolbar, or the Tools main menu. This will revert all views to the standard views. Screenshot