Preoperative evaluation of the deep cerebral veins using 3-Tesla magnetic resonance imaging

Background: Surgical treatment of deep-seated tumors such as supratentorial intraventricular and thalamic-pineal-tectal region tumors carries a risk of postoperative deficits due to possible damage to deep cerebral veins including the internal cerebral vein. It is often difficult to identify whether the vessel encountered during surgery needs to be preserved or not through the small operative field. Therefore, preoperative evaluation of deep venous structures is important. We evaluated the usefulness of 3-Tesla magnetic resonance imaging (3T MRI) for this purpose. Methods: First, the ability to detect deep venous structures was compared with both 3-dimensional computed tomographical angiography (3D-CTA) and 3T MRI in patients without any damage to deep venous structures. Images of 7 consecutive patients suffering from insulo-opercular gliomas who underwent both imaging modes for the identification of lateral striate arteries were reconstructed for evaluation of the deep cerebral veins. Subsequently, surgery for tumors at the supratentorial intraventricular and thalamic-pineal-tectal regions was prospectively performed with preoperative evaluation of deep venous system only using 3T MRI. Results: Information on the deep venous systems acquired by 3T MRI was as useful as that acquired by 3D-CTA. Until today, we have treated 8 cases of supratentorial intraventricular and thalamic-pineal-tectal region tumors with preoperative evaluation of the deep venous system using 3T MRI without any morbidity. Conclusion: Information on the deep venous system obtained with 3T MRI aids the surgery of supratentorial intraventricular and thalamic-pineal-tectal region tumors. As the required sequences of 3T MRI are same as those necessary for the neuronavigation system, and 3T MRI can be achieved without the use of iodine-based contrast agents, 3T MRI can be an alternative for preoperative evaluation of the deep venous systems.