3D-visualization and registration for neurovascular compression syndrome analysis

Abstract

Neurovascular compression syndromes are caused by a pathological contact between vessels and the root entry or exit zone of cranial nerves. Associated with a number of neurological diseases such as trigeminal neuralgia, hemifacial spasm or vertigo, there is also strong evidence for a direct relation with essential arterial hypertension. To treat the related conditions, operative microvascular decompression has proven to be very effective. So far, as a drawback for the examination, 2D representations of tomographic volumes served as exclusive source of information. Aiming at an improved spatial understanding, we introduce a noninvasive and fast approach providing clear delineation and interactive 3D visualization of all relevant structures. It is based on strongly T2 weighted MR volumes with sufficiently high resolution. Due to the size of the nerves and vessels at the brainstem, an explicit segmentation is extremely difficult. Therefore, we propose to segment only coarse structures with a sequence of filtering and volume growing. Consecutively, implicit segmentation with pre-defined transfer functions is applied to delineate the tiny target structures included in the area of cerebrospinal fluid. Additionally, we suggest registration with MR angiography to differentiate between vessels and nerves on one side and between arteries and veins on the other side. Overall, our approach contributes significantly to an optimized 3D analysis of vascular compression syndromes. The high value for the planning of surgery is demonstrated with several clinical examples.