Multi-planar reformatting (MPR)

is the process of using the data from axial CT images to create non axial 2D images. It is the process of creating sections or cuts through a volumetric dataset. MPR are coronal, sagittal, oblique, or curved plane images. A multi-planar reformatting can be defined in any arbitrary plane but most commonly orthographic views are used for visualization (Axial, Coronal & Sagittal). It is the most standardized method for visualization of 3D dataset or the method of choice for initial inspection.

The basic visualization configuration for displaying MPR data set is to present 3 orthographic views (Axial, Coronal & Sagittal) in three separate windows. Sometime with a cross hair tool. which is used to identify a landmark or a region of interest while keeping track of the same point in the other views. However, a mental correlation and 3D reconstruction is required and expected from the user.

Another visualization configuration for displaying MPR dataset is to visualize the 3 orthographic views in a single rendering window. This has the advantage of a better 3D correlation and mental reconstruction since the user is not disturbed by shifting his eyes away from the region of interest to identify the same region on the other views. However, in some cases the view may become obscured when the 3 views are orthogonal to each other which will require some camera rotation and zooming to enhance the view.

A 3D model (Surface or Volume rendered) can also be displayed overlayed with the orthographic views. It has the advantage of better orientation by being able to scroll through the slices to the region of interest. No mental reconstruction is required and correlation is enhanced. In most cases, it is actually faster to orient yourself in 3D and to identify the slice in question when you overlay a 3D surface with the 2D orthogonal slices which can foster the clinical work flow.