Clutter-free volume rendering for magnetic resonance angiography using fuzzy connectedness

Abstract

The purpose of this paper is to describe a practical method for the clutter-free, three-dimensional (3D) volume rendering of magnetic resonance angiographic (MRA) data. In MRA, clutter due to artifacts or nearby high-intensity structures prevents clear visualization of the vessel under investigation. We offer an alternative to the manual editing that is commonly used to remove clutter. The method is near automatic and requires the user to point at structures on a 3D maximum intensity projection (MIP) display. It utilizes recently developed fuzzy connected object delineation algorithms to extract the vessels of interest. Because the resulting definition is nonbinary, it can be displayed via MIP or more sophisticated volume-rendering techniques. The improved renditions are illustrated with several MRA studies. Implementation of the fuzzy connectedness method proved to be effective in removing the associated clutter in the images and, in some cases, dramatically improving visibility. Additionally, vessels could be extracted with a nominal number of points selected within the object by the user that retained most of the information present in the conventional MIP display. This could all be performed in a practical time frame: the first vessel delineation in 30 s, subsequent delineations in 2–10 s per view, all on a 100-MHz Pentium PC. Automatic delineation of vessels for 3D MRA visualization is feasible via fuzzy connectedness principles. The method retains the original intensity constitution, an advantage of the MIP method, and mostly eliminates the clutter commonly observed in MIP. Its speed and effectiveness make it feasible for routine clinical use.© 2000 John Wiley & Sons, Inc. Int J Imaging Syst Technol, 11, 62–70, 2000