Growing, erosive and infiltrative tumors of the skull base such as lymphomas, malignant sinonasal tumors, gliomas, pituitary adenomas, meningiomas, craniopharyngiomas and metastatic disease represent a large percentage of all intracranial tumors and pose some of the most complex challenges in neurosurgery. Not only is skull base tumor pathology difficult to treat, but the anatomic location of these tumors involves the most densely populated critical structures in the brain. Endoscopic endonasal surgery (EES) has transformed skull base tumor resection as it exploits safer, more direct, minimally invasive anatomical access routes to a large number of intracranial lesions. However, three major challenges still impede the use of EES. These are: 1) Injuries to blood vessels that are in close proximity to or encased within the tumor resulting in cataclysmic bleeding, 2) Accidental damage to the optic apparatus, including the optic nerve and chiasm and 3) Limited knowledge of tumor composition and boundaries, preventing safe and complete resection. Magnetic resonance imaging (MRI) at ultrahigh field strengths, such as 7 Tesla (7T), offers exceptional resolution and contrast and is particularly effective at elucidating nerves, vasculature, fiber tracts and tumor anatomy. We propose the first ever application of 7T multi-modal MRI to provide ultraprecise image guidance for endoscopic surgical planning and intra-operative decision-making. Our lab has the specific expertise in developing signal transmission tools, such as novel adiabatic radiofrequency (RF) pulses, to upgrade conventional imaging methods to robustly perform at ultrahigh fields. We hypothesize that our optimized 7T imaging techniques will depict tumor anatomy and adjacent structures in unprecedented detail, transforming pre- and intra-operative decision making for EES, and dramatically increasing the success rate, safety and applicability of the technique.