Clinical Efficacy of a Non-Invasive Measure of Intracranial Pressure

Inclusion Criteria: * Patients referred for a MRI by Attendings in the Department of Neurological Surgery at the University of Miam with intracranial pathology with external ventricular drains (EVDs) or intracranial bolts placed for hydrocephalus or intracranial hypertension. Bolts must be placed prior to enrollment in the study to avoid any alterations in standard procedure * All pathological entities that produce intracranial hypertension will be included (trauma, tumor, vascular, infectious, inflammatory, etc). * Patients must undergo a MRI for another clinically indicated reason (diagnosis, surveillance, cervical MRI clearance, prognosis, etc). * English and Spanish-speaking patients Exclusion Criteria: * Unable to obtain MRI due to prior implants, metallic material, inability to sit still * Refractory intracranial hypertension (not controlled with medications, surgery, or EVD) * Unable to obtain informed consent