P07.11 3-Tesla MR imaging in planning of microsurgical operations for deep brain tumors of pineal and mesencephalic region in pediatric patients

Abstract

Background: Pineal and mesencephalic tumors are deep brain lesions, and neurosurgical access to them is difficult and requires careful preoperative selection and preparing, especially in pediatric patients. Aim of the study: In preparing for microsurgical operation to it is very important to identify and analyze all anatomic structures including relationship between pineal gland, quadrigeminal plate and superior colliculi, and deep cerebral veins, that have to be preserved during operation, especially in children where venous variability and collaterals are uncertain. Methods: For pineal and deep brain lesions we used high resolution 3T-MR images (including MR angiography and MR venography) that clearly and precisely show all important neural and vascular structures that have to be preserved during surgery. In selected or uncertain MR images, for preoperative distinction of tumors from vascular malformations or developmental anomalies, we performed 3T-MR spectroscopy. For assessment of long functional tracts in cerebral white matter and visualizing axonal connections in the brain, in older children with multiple brain tumors we used 3T diffusion tensor tractography. Results: 3T-MR images show extraordinarily clear and precise relations between tumor and dorsal mesencephalon, exact location and inflow tributary branches of deep veins, and possible venous variations including left or right dominance of deep venous brain outflow. Conclusion: 3T-magnetic resonance imaging, MR angiography, MR venography, MR spectroscopy and diffusion tensor imaging are very useful in planning of successful operative approach. This helps to achieve minimal or absent operative morbidity and favorable result in microsurgical removal of brain tumors in children.