Currently, standard-of-care tractography is based on information obtained from diffusion tensor imaging (DTI). DTI is a diffusion magnetic resonance imaging (dMRI) technique that is routinely obtained on neurosurgical patients to assist in pre-operative planning. The primary objective of the proposed study is to determine the ability of msHARDI-based tractography to discern fibers in edematous brain regions.

Inclusion Criteria:

• brain lesions, including but not limited to tumors, epileptic foci, and vascular abnormalities, in or around eloquent brain regions (i.e., motor, language);
• clinical need for pre-operative 'advanced imaging' (which includes conventional DTI);
• age between 18-80 years of age;
• male or female gender. Eloquent regions include: Temporal and frontal lobes (speech/language); bilateral occipital lobes (vision); bilateral parietal lobes (sensation); and bilateral motor cortex (movement).

Exclusion Criteria:

• a contraindication for obtaining an MRI scan (e.g. implanted devices, retrained foreign body)
• pregnancy
• absence of the capacity to make medical decisions or provide informed consent.

patients with brain lesions near eloquent cortex