Tissue Selective Magnetic Resonance Subtraction Venography

We have developed a procedure to image the major veins of the brain using three dimensional magnetic resonance imaging sequences. This procedure is based on the selective enhancement of blood vessels following intravenous administration of contrast media such as gadolinium. A simple subtraction is performed between the post-contrast and pre-contrast MR images after correcting for overall intensity differences. The brain is segmented from the precontrast image volume. The resulting segmentation mask is dilated and used to extract the vessels of brain from the subtraction volume. The veins are reconstructed in three dimensions for visualization. The resulting tissue selective magnetic resonance venography is comparable to projection angiography for the larger veins. This procedure has been incorporated into a three dimensional stereotactic neurosurgical planning system.