A comprehensive survey of imaging-based methods of measuring intracranial pressure

Intracranial pressure (ICP) measurement is vital in managing and treating patients with brain injuries, brain tumors, and other neuro-ophthalmic conditions. Invasive methods have reached a high standard of accuracy but pose multiple risks to patients and require specialized resources. In contrast, non-invasive methods indirectly estimate ICP based on related physiological properties. This paper surveys imaging-based methods that utilize cerebro-ophthalmic anatomy and fluid dynamics. The theoretical basis of each method is presented, including the physiological attributes and imaging modality used. Details of empirical studies are also presented, including subjects (type, population, medical indication, captured anatomies), methodology, and evaluations of ICP estimation accuracy. The pros and cons of each method are presented in terms of complexity, patient acceptability, operating expertise, potential for clinical application, costs, and time. Whilst none of the methods in the survey has to date achieved the reliability and accuracy of invasive methods used clinically, those based on transcranial and orbital ultrasonography and direct retinal imaging demonstrate great promise. Refinements to these methods, including the application of modern deep learning techniques, offer the prospect of non-invasive, clinically acceptable, accurate and automatic measurement of ICP.