Any segmentation method may be prone to error. Surface rendering of segmented image objects may provide a beautiful display, but the utility of such renderings is useful only insofar as the initial segmentation was correct. An alternative display method is by volume rendering, which shows the actual image data. However, traditional methods of volume rendering are slow in the absence of specialized hardware and do not allow manipulation of individual objects or groups of objects.

We have develeped methods of interactively fast volume rendering of segmented image objects that allows simultaneous display of the actual image data and manipulation of individual objects or groups of objects. A feature of the method is that it allows arbitrary dilation of the segmentation boundaries so that more of the actual image data are shown. The approach provides two alternative visualization methods: a surface rendering about the surface of each object, and a deep volume rendering that casts rays selectively through the confines of each segmented object. The method can also be combined with surface rendering of additional objects.

Volume rendered tumor shown at partial opacity together with surface rendered, colored vessel trees.

Bullitt E, Aylward S (2001) Volume rendering of segmented tubular objects. MICCAI 2001 LNCS 2208: 161-168. <pdf>

Bullitt E, Aylward S. (2002) Volume rendering of segmented image objects. IEEE-TMI 21:998-1002 <pdf>