Feasibility of intraoperative MRI guidance for craniotomy and tumor resection in the semisitting position

Intraoperative magnetic resonance imaging (iMRI) has emerged as a reliable and useful tool in intracranial brain tumor surgery. Patient placement in a semisitting position may be advantageous in certain cases, but has so far seemed incompatible with conductance of iMRI-guided procedures. The general iMRI setup and the imaging protocol were tested and described earlier. Having performed a preliminary phantom study and a minimally invasive burr-hole procedure in the semisitting position, we have transferred our setup into craniotomy: an iMRI-guided microsurgical tumor resection was performed in a patient with a recurrent glioblastoma in the occipital lobe extending to the corpus callosum using a mobile 0.15 Tesla iMRI system. All safety precautions commonly used in semisitting craniotomy were also applied. Patient positioning as well as preoperative and intraoperative image acquisition could be accomplished. Tumor resection was performed in a standard microsurgical image-guided manner using neuronavigation. On intraoperative imaging, we could demonstrate complete resection of enhancing tissue, which was later confirmed by early postoperative high-field MRI. After our established protocol of patient monitoring, no complications or adverse events were noted intraoperatively or in the early or late postoperative phases. The iMRI-guided brain tumor resection is feasible in combination with semisitting patient positioning. However, special safety precautions must be followed.