Three-dimensional display of cortical anatomy and vasculature: Magnetic resonance angiography versus multimodality integration

We present two methods for acquiring and viewing integrated three-dimensional (3D) images of cerebral vasculature and cortical anatomy. The aim of each technique is to provide the neurosurgeon or radiologist with a 3D image containing information which cannot ordinarily be obtained from a single imaging modality. The first approach employs recent developments in MR which is now capable of imaging flowing blood as well as static tissue. Here, true 3D data are acquired and displayed using volume or surface rendering techniques. The second approach is based on the integration of x-ray projection angiograms and tomographic image data, allowing a composite image of anatomy and vasculature to be viewed in 3D. This is accomplished by superimposing an angiographic stereo-pair onto volume rendered images of either CT or MR data created with matched viewing geometries. The two approaches are outlined and compared. Results are presented for each technique and potential clinical applications discussed.