The 3D Cursor tool can be displayed for better correlation of the anatomy when browsing series with different image planes (e.g. Magnetic Resonance study, CT study). It is visible as a blue cross-hair cursor that marks the same point in 3D space on all images.
Hold Shift and drag the mouse, with its left button pressed to change the position of the cursor in the active window. Images in other windows will be scrolled automatically so that the displayed image plane is closest to the 3D cursor. Localizer line will temporarily hidden when the 3D Cursor is active.
If the cursor is located at some distance from the image plane (and no image with a closer plane can be found), it will be displayed in the red color(The projection point to the image plane is displayed).
The 3D Cursor command can be assigned to the left mouse button by choosing it from the toolbar menu or by pressing the Q key
This feature is also available in MPR and 3D images. For 3D images, the projection of 3d cursor point will be displayed on the 3D image