Cerebrovascular biomodelling: A technical note

BACKGROUND Recently computed tomographic angiography (CTA) and MR angiography (MRA) ha ve been used to image cerebrovascular structures. Although CTA and MRA are accurate and sensitive imaging modalities, limitations have been identified in relation to image interpretation. Stereolithographic (SL) biomodelling is a new technology that allows three-dimensional (3D) CT and NIR data to b e used to accurately manufacture solid plastic replicas of anatomical struc tures. A prospective trial of SL biomodelling in cerebrovascular surgery ha s been performed to investigate the feasibility and clinical utility of thi s new display medium. METHODS Fifteen patients with cerebral aneurysms and 1 patient with a cerebral arte riovenous malformation (AVM) were selected. 3D CT and/or MR angiograms were acquired and 19 solid anatomical biomodels manufactured using the rapid pr ototyping technology of stereolithography. The biomodels were used for pati ent education, diagnosis, operative planning and surgical navigation. RESULTS The biomodels replicated the CTA and MRA source data. The accuracy of one b iomodel was verified by comparison with a post mortem specimen, which corre sponded exactly in the x and y planes but differed by 2 mm in the z plane. The ability to closely study an overview of complex cerebrovascular anatomy from any perspective on a solid biomodel was reported to enhance the surge on's understanding, particularly when conventional images were equivocal. C erebrovascular biomodels were found to be useful when positioning the patie nt's head for surgery, for selecting the best aneurysm clip and for the sim ulation of clipping. Patient informed consent was anecdotally improved. Dis advantages of the technology were the cost and manufacturing time. CONCLUSIONS Cerebrovascular biomodelling may have utility in complex cases or when the standard imaging is felt to be equivocal. (C) 1999 by Elsevier Science Inc.