Computer-assisted visualization of arteriovenous malformations on the homepersonal computer

OBJECTIVE: Arteriovenous malformations (AVMs) are difficult lesions to trea t, partly because it is difficult to formulate a three-dimensional mental i mage of the nidus and its supplying arteries, draining veins, and arteries of passage. Our purpose is to develop personal computer software that allow s better visualization of complex, three-dimensional, connected vascular an atomy for surgical planning. METHODS: Vessels are defined from magnetic resonance angiograms and are sym bolically linked to form vascular trees. The nidus of the AVM is also defin ed by magnetic resonance angiography. These representations of the nidus an d vasculature can be viewed together in a software program that allows the user to color-code groups of vessels or to selectively turn connected group s of vessels "off" to avoid obscuring the part of the image that the user w ants to observe. Structures can be viewed from any angle. The vessels can a lso be shown intersecting any magnetic resonance angiogram slice or superim posed upon digital subtraction angiograms obtained from the same patient. RESULTS: We report results from two patients with AVMs in which our represe ntations were compared with the findings during surgery. Our three-dimensio nal vascular trees correctly depicted the relationship of the nidus to feed ing vessels in three dimensions. We show findings in an additional, unopera ted patient for whom vessel trees were created from three-dimensional digit al subtraction angiography data and compared with a volume rendering of the original data set. CONCLUSION: Computer-assisted, three-dimensional visualizations of complex vascular anatomy can be helpful in planning the surgical excision of AVMs. Software programs that produce these images can provide important informati on that is difficult to obtain by traditional techniques. This imaging meth od is also applicable to guidance of endovascular procedures and removal of complex tumors.