Clinical applications of integrated 3-D stereoscopic imaging in neurosurgery

Stereotactic neurosurgery planning, an intrinsically three-dimensional procedure, is generally performed on the basis of two-dimensional tomographic or projection images. We present extensions to these conventional approaches that use stereoscopic digital subtraction angiography, three-dimensional volume rendered computed tomography or magnetic resonance images, or a combination of these modalities. The stereoscopic DSA images are analysed interactively on a 3-D workstation. This system employs a liquid-crystal polarizing shutter to display alternate left- and right-eye views to a user wearing polarized glasses. Quantitative planning operations may be performed on the basis of the angiograms alone, or in conjunction with tomographic images of the anatomy. We also describe the procedures used to produce volume-rendered three-dimensional images from MR and CT data-sets, as well as the methodology for combining the stereoscopic angiograms with the volumetric anatomical images.