Recent advances and future directions in ophthalmologic neuroimaging

Advances in neuroimaging over the past 5–10 years have offered opportunities to address challenging and previously unanswered clinical questions in ophthalmologic neuroimaging. Among these advances are diffusion-weighted imaging, diffusion-tensor imaging (DTI), perfusion MRI (PWI), functional MRI (fMRI) as well as single-photon emission tomography, PET scanning and high-frequency contrast harmonic ultrasound imaging. The MRI techniques are based on imaging the static or dynamic changes of the hydrogen proton in a controlled magnetic field. Diffusion-weighted imaging, for instance, offers temporal characterization of acute infarction and differentiation of neoplasm from bacterial abscess, or differentiation between certain types of neoplasms that may present with visual symptoms. The addition of PWI allows rapid assessment of tissue at risk (penumbra) beyond the core (umbra) in the setting of acute stroke. PWI, computed tomography perfusion and high-frequency contrast harmonic imaging are used to study the...